NanoPT2015

The 16th edition of the Trends in Nanotechnology International Conference (TNT2015) is being launched following the overwhelming success of earlier Nanotechnology Conferences.

Lead Organiser

September 07-11, 2015

www.tntconf.org/2015

Inde x

Foreword / Organisers

Page 5

Sponsors/Committees

Page 6

Exhibitors

Page 7

Speakers

Page 12

Abstracts

Page 17

Posters List

Page 109

F o re wor d We take great pleasure in welcoming you to Porto (Portugal) for the 3rd edition of the nanoPT International Conference (nanoPT2015).

The third edition will be held with the purpose of strengthen ties nationally and internationally on Nanotechnology and, pretends to be a reference in Portugal in the upcoming years. This conference will encourage industry and universities working on the Nanotechnology field to know each other and to present their research, allowing new collaborations between nearby countries such as Spain and France. nanoPT 2015 will let participants to present a broad range of current research in Nanoscience & Nanotechnology, not only the most prominent investigations/studies in Portugal but from all over the World.

We are indebted to the following Institutions for their financial support: American Elements, International Iberian Nanotechnology Laboratory (INL) and FEI. We would also like to thank the following companies and institutions for their participation: Raith GmbH, Kurt J. Lesker, SOQUIMICA, Fritsch, BIOPTICA, Oerlikon Leybold Vacuum, NT-MDT, CRESTEC Corporation and ScienTec IbĂŠrica.

In addition, thanks must be given to the staff of all the organising institutions whose hard work has helped planning this conference.

O rga n ise r s

nanoPT2015 Porto (Portugal)

|5

Spo ns or s

Comm ittee s

Organizing Committee Antonio Correia Phantoms Foundation (Spain) Braz Costa CITEVE/CENTI (Portugal) Lars Montelius INL (Portugal) Jose Rivas Santiago de Compostela Univ. (Spain) Vasco Teixeira Univ. Minho (Portugal)

Scientific Committee Jean-Pierre Aimé UMR 5248 CBMN CNRS - Universite Bordeaux (France) Stephan Roche ICN2 (Spain) Juan José Sáenz UAM (Spain)

Technical Committee Viviana Estêvão Phantoms Foundation (Spain) Jose Luis Roldán Phantoms Foundation (Spain)

6|nanoPT2015 Porto (Portugal)

E xh i bi t o rs

SOQUIMICA Since 1929, SOQUIMICA commercializes high quality laboratory equipment and provides highly specialized services to its customers.

We offer our clients the expertise of a qualified and experienced team, which enables support for the development of tailor-made solutions.

The equipment we sell and the services we provide allow our customers to enjoy the best solutions for various Applications (Chemical analyzes, Gas and liquid chromatography, Spectroscopy, Genomics, Life sciences, Laboratory Weighing, Industrial Weighing, Preparation of samples) and Industries (Environment, Forensics and Toxicology, Energy & Chemicals, Food Industry and Agriculture, Pharmaceuticals and Biotechnology Industry, Textile Industry, Inspection of products and materials testing, Clinical research, Refinery & Petrochemicals). www.soquimica.pt

nanoPT2015 Porto (Portugal)

|7

Oerlikon Leybold Vacuum Oerlikon is a worldwide leading high-tech industrial group, specialized in mechanical and industrial engineering. Oerlikon Leybold Vacuum is the vacuum part of the Oerlikon Group. We offer a wide range of advanced vacuum solutions for research purposes and analytical processes, as well as for manufacturing processes. The company's core capabilities center on the development of application and customer specific systems for the creation of vacuum and extraction of process gases. Oerlikon Leybold Vacuum's ability to meet highest requirements of most complex applications gives our customers the competitive edge to succeed. High duty processes in metallurgy, clean-room conditions at worldwide renowned institutes for research and development, or coating applications of minute dimensions – Oerlikon Leybold Vacuum offers highest performance. In Spain the daughter company was established in 1964, being currently responsible for Spain and Portugal. www.oerlikon.com/leyboldvacuum/spain/es

Raith Raith offers innovative solutions for sub-10nm focused ion beam (FIB) nanofabrication, SEMbased electron beam lithography (EBL), large area SEM image capture, gas-assisted nanolithography, in situ nanomanipluation and nanoprofilometry. Raith’s proprietary FIB technology offers a wide range of ion species and elevates FIB based nanofabrication to a new level with highest selectivity and unsurpassed stability for automated wafer-scale patterning. nanoPT2015 Contact: Mr. Vincent Morin Raith GmbH Konrad-Adenauer-Allee 8 44263 Dortmund / Germany www.raith.com sales@raith.com

8|nanoPT2015 Porto (Portugal)

Crestec Corporation CRESTEC is a worldwide Electron Beam Lithography system manufacturer. We are going to present our new product CABL-UH series which is equipped with the world the highest acceleration voltage 130kV this time. The existing Electron Beam Lithography system series CABL-9000C will be displayed and its upgraded basic performances and writing capabilities will be described by display panels. We are offering sample fabrication services suitable for customers needs.

Contact: Crestec Corporation 1-9-2 Owada-machi, Hachioji-shi, Tokyo, 192-0045 Japan +81-42-660-1190 sales@crestec8.co.jp www.crestec8.co.jp

Bióptica For more than 20 years Bióptica, LDA works with Horiba Scientific, a global leader in fluorescence and Raman spectroscopy. Horiba Scientific has a full range of solutions in the nano-spectroscopy field: AFM-Raman, TERS, NSOM, chemical imaging at the nanoscale, nanofluorescence/TCSPC and ellipsometry.

Bioptica, LDA also commercializes: − − − − −

Continuum/Amplitude Systèmes; Laser Quantum/Venteon; CVI Melles Griot; A complete light measurements solutions from the leading company Instrument Systems, GmbH; Cytoviva Hyperspectral Imaging technology designed to provide spectral characterization and mapping of nano-materials.” www.bioptica.pt

nanoPT2015 Porto (Portugal)

|9

NT-MDT From cutting edge scientific research to routine surface investigations, NT-MDT has a unique and unrivalled portfolio of scanning probe microscopes. Our application-focused instruments provide you with a full range of capabilities in AFM-Raman, high-resolution, multi-frequency measurements, and AFM based nanomechanics. As an innovator in SPM for over 20 years, NTMDT has a specialized high-performance solution for your research needs.

Key Products: SPM/AFM/STM; Raman TERS; Spectroscopy info@ntmdt.us www.ntmdt.us

ScienTec Ibérica ScienTec Ibérica, is the spanish branch of ScienTec France, its mission is to serve and attend the Iberian Nano-micro surface analysis market from its office in Madrid. Its field of activity is related to scientific research, R&D and industrial metrology. In terms of product line, we deal with atomic force microscopes, contact profilometry, digital holography, interferometry, nanoindentation, filmetrics and high aspect ratio confocals. Recently we have expanded our portfolio to customized UltraHigh Vacuum Systems, XPS;ESCA… ScienTec Ibérica accompanies you in your various projects by offering system adapted to your applications (nanotechnology, polymer, material surfaces, biology, semiconductor, microfabricaiton and the cutting tool industry…). www.scientec.es

Kurt J. Lesker Company As a leading global provider of high-quality vacuum products and systems, along with an established tradition of service and attention to detail, the Kurt J. Lesker Company® (KJLC®) has built a reputation for “Enabling Technology for a Better World”.

The common attribute across the entire company is the relentless and tireless pursuit of quality and customer satisfaction, both in the vacuum products and the services we provide worldwide.

KJLC takes this responsibility seriously, working at all levels to ensure high quality performance in all our products. www.lesker.com

10 | n a n o P T 2 0 1 5 P o r t o ( P o r t u g a l )

Sp e ak er s

Index alphabetical order K: Keynote Speakers O: Orals (Plenary Session) OP: Orals (Parallel Session)

Spe a k e rs Page

Al-Mutairi, Eid (Chemical Engineering Department, Saudi Arabia) “Design and Optimization of CNTs Production in Chemical Vapor Deposition Reactor” Andrade, Suzana M. (Instituto Superior Técnico - Centro de Química Estrutural, Portugal) “Toward multifunctional gold nanoparticles/graphene hybrid assemblies associated to photoactive molecules” Araújo, José (REQUIMTE / University of Porto, Portugal) “Surpassing NSAIDs side-effects with Lipid Nanoparticles” Artacho, Emilio (CIC nanoGUNE, Spain) “On the origin and switching of a two -dimensional electron gas under a thin perovskite film” Bagaturyants, Alexander (Photochemistry Center RAS, Russia) “Multiscale Atomistic Modeling of Amorphous Organic Functional Materials for Optical Chemical Sensing and OLED Applications” Bettencourt, Ana (Universidade de Lisboa, Portugal) “Does surface charge play a role in nanoparticulate-systems toxicity?”

Bonaccorso, Francesco (IIT, Italy) “Solution processing of grapheme, related 2d crystals and hybrid structures for energy conversion and storage” Borme, Jerome (INL - International Iberian Nanotechnology Laboratory, Portugal) “Wafer-scale fabrication of solution-gated graphene field-effect transistors for biosensing applications” Carrola, Joana (University of Aveiro, Portugal) “Metabolic effects of silver nanoparticles assessed by NMR metabolomics of mice liver and serum” Carvalho, Filomena (Instituto de Medicina Molecular, Portugal) “AFM as a nanotool to evaluate protein-cell interactions and cell-cell adhesion on cardiovascular pathologies” Costa, José Diogo (International Iberian Nanotechnology Laboratory (INL), Portugal) “Nanofabrication of Magnetic Tunnel Junction Pillars Targeting Nano-Oscillator Applications” Costa, Pedro (Physical Sciences and Engineering Division, Saudi Arabia) “The structure and chemistry of CNTs in electrical nanodevices fabricated by beam deposition” Cruz, Fernando (Requimte/CQFB, Universidade Nova de Lisboa, Portugal) “Thermodynamics of DNA Strands Encapsulated into Electrically Charged Nanotubes” Cunha, Eunice (Instituto de Polímeros e Compósitos, Portugal) “Exfoliation of graphite using pyrene and perylene derivatives” Ferreira, Mauro (Trinity College Dublin, Ireland) “Sublattice asymmetry of substitutionally doped impurities in graphene” Ferreira, Quirina (Instituto de Telecomunicações, Portugal) “Biocompatible and nanostructured monolayers on graphite for drug delivery applications” Figueiras, Fábio Gabriel (IFIMUP-IN Univ. Porto & CICECO Univ. Aveiro, Portugal) “Nanometric Bias Induced Phase Transitions in materials”

OP

19

O

20

OP

22

K

23

O

25

O

27

K

29

O

30

OP

32

O

34

OP

36

O

38

O

39

OP

41

O

43

O

44

O

45

nanoPT2015 Porto (Portugal)

| 13

Page Fortunato, Elvira (CENIMAT-I3N , Portugal) “A review on metal oxide semiconductors applied to transistors: from nanofilms to nanoparticles” Freidzon, Alexandra (Photochemistry Center, Russian Academy of Sciences, Russia) “Spectral and Transport Parameters of Electron-Transporting Materials Bis(10-hydroxybenzo[h] qinolinato) beryllium (Bebq2)” Frias, Iúri (REQUIMTE / University of Porto, Portugal) “Development of lipid nanocarriers-based epigallocatechin gallate for preventive and therapeutic supplementation” Fu, Guodong (Southeast University, China) “Preparation of Fluorescent Organometallic Porphyrin Complex Nanogels” Gaspar, André (Universidade de Coimbra, Portugal) “Development of a biodegradable magnetic nanoprobe using SPIONs and Amazonian essential oils” Gaspar, Vitor (CICS-UBI - Health Sciences Research Centre, Portugal) “Simultaneous Delivery of Drugs and Genes by Multi-block Polymeric Nanomicelles for Synergistic Cancer Therapy” Gnilitskyi, Iaroslav (University of Modena and Reggio Emilia, Italy) “Strongly anisotropic wetting on highly-uniform self-similar molybdenum nanogrooves” Gomes, João (CENTI, Portugal) “Optimization of processing and encapsulation conditions of white OLED devices for decorative lighting applications” Gouveia, Virgínia (REQUIMTE / University of Porto, Portugal) “pH sensitive liposomes loading prednisolone for the treatment of rheumatoid arthritis” Ilyas, Muhammad (Brunel University London, United Kingdom) “Use of Nano-Technology and Nanomaterial in the Development of Nanocomposite Cementitious Materials” Kolen'ko, Yury V. (International Iberian Nanotechnology Laboratory (INL), Portugal) “p-Type Cu2O colloids optimized for photoelectrochemistry and electronics” Kuzmenko, Igor (Ben Gurion University of Negev, Israel) “Two-Channel Kondo Effect in Carbon Nanotube Quantum Dot” Lee, Seunghwan (Technical University of Denmark, Denmark) “Mucoadhesion to Improve Slipperiness of Mucin Layers” Lima, Sofia (REQUIMTE / University of Porto, Portugal) “Temperature-responsive polymeric nanospheres containing methotrexate and gold nanoparticles: a multi-drug system for theranostics in rheumatoid arthritis” Liu, Lifeng (INL, Portugal) “Extraordinarily Efficient Electrocatalytic Hydrogen Evolution Achieved by Amorphous MoOxSy Catalysts Electrodeposited on Crystalline TiO2 Nanotube Arrays” Martinsone, Zanna (Rigas Stradins University, Latvia) “Instrumentation for qualifying and quantifying nanoparticles’ exposure into occupational environment” May, Mousa (Sebha University, Libya) “Effects of γ-Al2O3 nanoparticles on the adhesive strength of composite epoxy/sol-gel materials” Merkoçi, Arben (ICN2, Spain) “Nanobiosensors and applications in diagnostics” Mohseni, Farzin (Universidade de Aveiro, Portugal) “Magnetic and morphologic properties of Alnico-based rare-earth free permanent magnets” Montelius, Lars (INL - International Iberian Nanotechnology Laboratory, Portugal) “Bridging the materials gap through radical Innovations”

14 | n a n o P T 2 0 1 5 P o r t o ( P o r t u g a l )

K

46

OP

47

OP

48

O

49

OP

50

OP

52

OP

53

K

55

OP

56

OP

57

O

59

O

60

O

62

O

64

O

66

OP

67

OP

69

K

70

OP

71

K

73

Page Moreira Pinto, Artur (LEPABE, Portugal) “Effect of biodegradation on PLA/graphene-nanoplatelets composites mechanical properties and biocompatibility” Morin, Vincent (Raith GmbH, Germany) “Ion Column and Source technology employing Gallium and New Ion Species for Advanced FIB Nanofabrication” Neves, Ana (University of Exeter, United Kingdom) “Graphene-coated transparent conducting fibres for smart textiles” Nieder, Jana Berit (INL-International Iberian Nanotechnology Laboratory, Portugal) “Presentation of the New “Ultrafast Bio-and Nanophotonics” Laboratory at INL” Onida, Giovanni (Istituto Nazionale di Fisica Nucleare (INFN), Italy) “Carbon sp wires and their coupling to graphene” Pereira, Maria (Universidade de Aveiro, Portugal) “Scanning Thermal Microscopy: unraveling and mapping thermal phenomena at the nanoscale” Peressi, Maria (University of Trieste, Italy) “Seeding, nucleation and reactivity of alumina/Ni3Al(111)supported metallic nanoclusters: an ab-initio investigation” Perez Roldan, Maria Jesus (CIC nanoGUNE Consolider/Advanced microscopy, Spain) “One step FEBID fabrication of Co based magnetic nanotubes” Pinto, Inês (INL - International Iberian Nanotechnology Laboratory, Portugal) “Epithelial Tumor Dynamics: Nanocharacterization of force-generating structures” Queiroz, Joana (REQUIMTE / University of Porto, Portugal) “New insights in the development of solid lipid nanoparticles for active brain-targeted drug delivery” Rana, Sohel (University of Minho, Portugal) “Development of Ductile Cementitious Composites Using Carbon Nanotubes” Raposo, Claudia (IBET, Portugal) “Synthesis of novel galactose-PLGA nanoparticles containing doxorubicin for hepatocyte targeting” Repetto, Diego (University of Genoa, Italy) “Transparent aluminum nanowires electrodes with optical and electrical anisotropic response fabricated by defocused ion beam sputtering” Ribeiro, Daniela (ICETA/REQUIMTE/FFUP, Portugal) “Characterization of Model Membranes under the Effect of Anticancer Drugs” Rios, Angel (University of Castilla-La Mancha, Spain) “New approaches in the development of analytical methodologies involving the use of CdSe/ZnS quantum dots” Rosário, Carlos (Universidade de Aveiro, Portugal) “Resistive switching and impedance spectroscopy in metal-oxide-metal trilayers with SiOx and ZrO2: a comparative study” Seah, Choon Ming (Institut Jean Lamour, CNRS-Université de Lorraine, France) “An Improved Wet Chemical Approach For The Separation Of Graphene From Nickel Foil ToThe Reutilization Of Catalyst” Serrano Núñez, Juan Manuel (Sesderma, Spain) “Repair of UV light-induced dna damage” Silveirinha, Mario (Universidade de Coimbra, Portugal) “Taming light at the nanoscale with metamaterials” Soto Beobide, Amaia (Foundation for Research&Technology-Hellas– Institute of Chemical Engineering Sciences, Greece) “Carbon Nanotube reinforced Textiles for Civil Protection Services”

OP

74

O

76

O

78

OP

79

O

80

OP

81

O

83

O

84

K

108

O

85

O

86

O

88

O

89

O

90

O

91

OP

93

OP

95

OP

96

K

98

OP

99

nanoPT2015 Porto (Portugal)

| 15

Page Tarequzzaman, Mohammad (International Iberian Nanotechnology Laboratory, Portugal) “Large power emission in MTJ based spin torque nano-oscillators using a free layer near the in-plane to out-of plane transition” Vila, Ana (International Iberian Nanotechnology Laboratory (INL), Portugal) “Designed Nanocomposite Magnetic Beads for isolation of Circulating Tumor Cells (CTC)” Vila, Mercedes (University of Aveiro , Portugal) “Nanographene Oxide mediated cell hyperthermia” Wang, Xiaoguang (International Iberian Nanotechnology Laboratory (INL), Portugal) “Direct Growth of Nickel Phosphoride Nanoneedles on Nickel Foam for Efficient Electrocatalytic Hydrogen Evolution” Yerchuck, Dmitri (Heat-Mass Transfer Institute of National Academy of Sciences of RB, Belarus) “New Quantum Physics Phenomena in Optical and Radio Spectroscopies”

16 | n a n o P T 2 0 1 5 P o r t o ( P o r t u g a l )

OP

101

O

103

K

104

OP

105

OP

107

A b s tr ac ts

Eid M. Al-Mutairi

Design and Optimization of CNTs Production in Chemical Vapor Deposition Reactor

Chemical Engineering Department , King Fahd University of Petroleum & Minerals, Dhahran 31261, Saudi Arabia

The Chemical Vapor Deposition (CVD) parameters were studied to selectively synthesize Carbon Nano Tubes (CNT’s). Experimental runs using Vertical Chemical Vapor Deposition (CVD) reactor were performed at a fixed reaction time of one hour and different operating temperatures (700-1000 Co), hydrogen flow rates (100-3000 mL/mint) and Pxylene flow rates (5-40 mL/hr). Ferrocene [Fe (C5H5)2] catalyst was used in the process in the form of powder which is mixed and dissolved with Pxylene (C8H10) at a ratio of 1% of Fe (50 mL solvent, 1.6 g Ferrocene) to the hydrocarbon. The P-xylene as the source of the hydrocarbon was cracked by hydrogen while argon gas was used to flush the CVD reactor to prevent oxidation of the catalytic metal at the reaction temperatures. Effects of the various operating parameters on the yield and quality of CNT’s such as temperature and the flow rates of hydrocarbon and hydrogen are presented in this study. The effects of the different reaction conditions on the CNT’s yield and various dimensions of the CNTs formed were also investigated. A design of experiment package was

used for the generation and evaluation of statistical k experimental designs. A 3 statistical factorial design approach was adopted to develop the mathematical models in order to study and optimize the operating conditions.Multiple Linear Regression (MLR) was used to fit the mathematical models. The morphologies of the CNTs were characterized and examined by Scanning Electron Microscopy (SEM) at different growth temperatures for the surface morphology of the samples and Thermal Gravity Analyzer (TGA) was used to analyze purity of CNT’s.

A design of experiment optimizer was used to find the optimum conditions for the yield and quality of CNT’s where optimum yield was found to be at a temperature of 892 Co and H2 flow rate of 1497 mL/mint with P-xylene rate of 5 mL/hr. However, to control quality, higher H2 flow rate (3000 mL/mint) need to be considered to improve average diameters and aspect ratios of the produced CNT’s.

nanoPT2015 Porto (Portugal)

| 19

Suzana M. Andrade1, C.J. BuenoAlejo1, V. Vaz Serra1,2, S.M.B. 1 3 Costa , P. Serp 1

Centro de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa-Portugal 2 Departamento de Química & QOPNA, Universidade de Aveiro- Portugal 3 Laboratoire de Chimie de Coordination UPR CNRS, composante ENSIACET, Toulouse University – France

Toward multifunctional gold nanoparticles/graphene hybrid assemblies associated to photoactive molecules

suzana.andrade@tecnico.ulisboa.pt

Light-induced doping with excited-state electron donors or electron acceptors is a versatile strategy for the fabrication of photoactive carbon-based nanocomposites (CBN).

Important contributions stem from π−π interactions with amphiphilic porphyrinoids. Depending on the architecture organization, photophysical studies showed strong electronic communications between the chromophoric moieties and carbon nanotubes [1].

Gold nanoparticles (AuNP) are one of the most interesting nanostructures. Among their excellent properties, the presence of a surface plasmon band in the visible region of the electromagnetic spectrum makes these materials suitable for many attractive applications in fields such as medicine, sensors, and catalysis. For these applications, an optimization of the gold particle size, the distribution of particle sizes and their dispersion on the graphene surface is desirable.

With this in mind, we have prepared AuNP supported by different CBN: graphene oxide (GO), N-doped graphene (N-G) and soft functionalized graphene (fG). The AuNP were supported in two different ways: a) by a modification of the literature sonolytic method,[2] which consists in the sonication of the support and the Au salt in aqueous suspensions; b ) by the simple mixing of presynthesized AuNP with the support. The morphology and size distribution of the nanoparticles within the supports were studied by AFM and TEM. N-G was found to have a strong influence on the particle density and size distribution (Figure 1). Very fine particles in the size range of 1-3 nm were observed even though some particles were much bigger in size even up to 20 nm.

The covalent and non-covalent interactions of these hybrid materials with porphyrinoids (Por, Figure 2)

was subsequently investigated using both steadystate and time-resolved fluorescence, including FLIM microscopy. The luminescence quenching observed (Figure 3) is tentatively assigned to a competition between two possible processes: photoinduced electron transfer and energy transfer. However, in the presence of CBN-AuNP composites there is an enhancement of the porphyrinoid fluorescence involving a surface plasmon coupling effect. These new nanostructures are thus expected to have selective photocatalytic and sensing abilities.

References [1] S.M. Andrade, P. Raja, V.K. Saini, A.S. Viana, P. Serp, S.M.B. Costa, ChemPhysChem 13 (2012) 3622-3631.

[2] K. Vinodgopal, B. Neppolian, I.V. Lightcap, F. Grieser, M. Ashokkumar, P.V. Kamat, J. Phys.

Chem. Lett. 1 (2010) 1987–1993.

Acknowledgements: Project PTDC/Qui-Qui/117498/2010 funded by FCT is acknowledged.

20 | n a n o P T 2 0 1 5 P o r t o ( P o r t u g a l )

Figures

Figure 1: TEM images showing (a) GO, and AuNP anchored on (b) GO; (c) N-G and (d) fG (right) sheets, prepared using a modified sonolysis method.

Figure 2: Porphyrinoids used in this study: metamethoxy-phenyl porphyrin monosubstituted with a polylysine chain (MMA-PLL, left) and tetrasulfonated aluminium phthalocyanine (AlPcS4, right).

Figure 3: Left: Fluorescence spectra of Por/GO and Por/Au@GO (MMA-PLL, blue; AlPcS4, green); Center: FLIM images of MMA-PLL (top) and AlPcS4 (bottom) in the presence of GO; and Right: Fluorescence lifetime distributions of MMA-PLL (top) and AlPcS4 (bottom) alone and in the presence of Au@GO.).

nanoPT2015 Porto (Portugal)

| 21

Araújo J., Neves, A. R., Gouveia, V., Moura, C., Nunes, C. and Reis, S. REQUIMTE, Departamento de Química, Faculdade de Farmácia, Universidade do Porto, Porto, Portugal

Surpassing NSAIDs sideeffects with Lipid Nanoparticles

bio09089@fe.up.pt

The inflammatory process is the innate immune response for the presence of pathogens, toxic molecules, tissue injuries or any other harmful conditions. The inflammation process is characterized for redness, pain, swelling, heat and disturbance of function and comprises inducers, sensors, mediators and effectors components from cellular and humoral origin. Macrophages are one of the most important cells in the inflammatory process. Macrophages actively phagocyte particles with sizes superiors to 200 nm and express folate receptor making them of great interest for passive and active targeting strategies. Non-Steroidal AntiInflammatory Drugs, like oxaprozin, are one of the most used drugs prescribed for these conditions, however these drugs have adverse side effects, namely at the level of the gastric mucosa, that must be avoided and pharmacokinetic properties that need to be improved and for these purpose many delivery systems arise. Lipid Nanoparticles allow an effective drug packaging and targeted delivery, improving drug´s pharmacokinetics and pharmacodynamics properties and avoiding some

of their side effects. In this work, two formulations containing oxaprozin were developed: nanostructured lipid carriers with and without folate functionalization obtained by the addition of a synthesised DSPE-PEG2000-FA conjugate. These formulations revealed high stability, low polydispersity and mean diameters that allowed macrophages passive targeting along with high encapsulation and loading capacity. The formulations avoided the oxaprozin release in simulated gastric fluid promoting its release on simulated intestinal fluid, physiologic and inflammatory medium, remaining only a small amount entrapped on the lipid carrier matrix. MTT and LDH assays revealed that the formulations only seemed to present cytotoxicity in Caco-2 cells, for oxaprozin concentrations superiors to 100 μM and permeability studies in the same cell line shown that oxaprozin encapsulation on the lipid nanoparticles did not interfere with oxaprozin permeability.

22 | n a n o P T 2 0 1 5 P o r t o ( P o r t u g a l )

N. Bristowe1, P. Aguado-Puente2, R. Shirasawa3, B. Yin2,4, P. Littlewood5,6, 7 2,8,9 Ph. Ghosez and E. Artacho 1 Department of Materials, Imperial College London, London, UK 2 CIC NanoGUNE and DIPC, San Sebastián, Spain 3 Department of Earth Sciences, University of Cambridge, Cambridge, UK 4 Department of Engineering Mechanics, Zhejiang University, Hangzhou, China 5 Physical Sciences and Engineering, Argonne National Laboratory, Argonne, USA 6 Department of Physics, University of Chicago, Chicago, USA 7 Départment de Physique, Université de Liège, Sart-Tilman, Belgium 8 Theory of Condensed Matter, Cavendish Laboratory, University of Cambride, Cambridge, UK 9 Basque Foundation for Science Ikerbasque, Bilbao, Spain

On the origin and switching of a two-dimensional electron gas under a thin perovskite film

e.artacho@nanogune.eu

Since the discovery of the two-dimensional electron gas (2DEG) that forms at the interface between a nanoscale thin film of LaAlO3 and a SrTiO3 substrate [1], the research on this and similar systems has been very active, leading to the discovery of a vast amount of different properties with potential practical applications [2]. The origin of such a 2DEG between two band insulators has remained controversial for some time. Our present understanding, in terms of a polarization discontinuity at the interface will be briefly reviewed, connecting with concepts that are now more topically associated to topological insulators [3].

Although the formation of a 2DEG has been observed in other oxide heterostructures, the prototypical system for these studies is still the original LaAlO3/SrTiO3 interface. Very early after the discovery of this system, the use of a ferroelectric substrate was proposed as a way to tune the population of the 2DEG. Since the ferroelectric material possess a non-volatile polarization, its switching with the application of an external electric field could be used to increase or decrease the polar discontinuity with the polar LaAlO3 and consequently turn on and off the 2DEG. First-principles simulations showed that this was physically feasible [4] but the experimental realization has not been achieved yet. A more radical approach to this problem considers the spontaneous polarization of a ferroelectric

material instead of the formal polarization of the centrosymmetric LaAlO3, suggesting that a 2DEG should also form under ferroelectric thin films due to a polarization discontinuity with a dielectric substrate or vacuum. If this were achieved a number of possible applications can be envisaged, such as non-volatile manipulation of the metallic interface. Here we present a combination of macroscopic models and first principles simulations aimed at explaining the precise conditions under which the formation of a 2DEG under a ferroelectric thin films might be viable and what the properties of the system would be. We study the competition between the electronic reconstruction and typical alternative screening mechanisms, paying special attention to the formation of polydomain structures. These results are used to propose routes to favor the formation of the 2DEG. The properties of the 2DEG formed at realistic ferroelectric surfaces or interfaces are analyzed using first principles simulations, taking explicitly into account the interaction with the substrate, the external fields, strain, and other instabilities present in the materials. The switching on and off of the 2DEG is obtained in the modeling and the calculations, displaying a discontinuity in the polarization and in the corresponding screening mechanism (the free carriers of the 2DEG) equal to Ps / √3, Ps being the equilibrium bulk polarization of the material.

nanoPT2015 Porto (Portugal)

| 23

References [1] A. Ohtomo and H. Y. Hwang, A high-mobility electron gas at the LaAlO3/SrTiO3 heterointerface, Nature 427, 423 (2004) [2] J. Manhart and D. G. Schlom, Oxide Interface – An opportunity for electronics, Science 327, 1607 (2010) [3] N. Bristowe et al., Origin of two-dimensional electron gases at oxide interfaces: insights from theory, J. Phys.: Condens. Matter. Topical Review, 26, 143201 (2014) [4] M. Niranjan et al. Prediction of a switchable 2dimensional electron gas at ferroelectric oxide interfaces, Phys. Rev. Lett. 103, 016804 (2009)

24 | n a n o P T 2 0 1 5 P o r t o ( P o r t u g a l )

Alexander Bagaturyants Photochemistry Center RAS, ul. Novatorov 7a, Moscow, 119421, Russia National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), Moscow, Russia bagaturyants@gmail.com

Multiscale Atomistic Modeling of Amorphous Organic Functional Materials for Optical Chemical Sensing and OLED Applications

Atomistic multiscale simulation is applied to modeling amorphous organic functional materials with specific optical or electronic properties.

Materials for optical chemical gas sensors and for organic light-emitting devices (OLED's) are considered as examples. The functionality of such materials is provided by constituting molecules that determine their specific functional properties.

In the case of sensing devices, these are so-called indicator molecules (IMs) changing their optical response (mostly, luminescence) upon interaction with a target molecule (detected or analyte molecule, AM). The goal of simulation in this case is to predict the optical properties of the entire structure (sensing material) and its response to various AMs. In the case of OLED's, these are lightemitting and electron- or hole-transporting molecules. The goal of simulation here is to predict the main electronic parameters of these molecules that determine the efficiency of a particular OLED. In both cases, the properties of functional molecules strongly depend on their local supramolecular environment, that is, on the microstructure of the amorphous material.

Therefore, a multiscale atomistic approach is used, in which molecular dynamics simulations are used to describe the microstructure of the material, and quantum chemical methods are used to calculate the required electronic properties of the functional molecules in the material. Commonly, a statistical treatment is required to obtain the distribution of wanted molecular properties or their averaged values in the real amorphous material. Problems arising at each step of modeling are analyzed, and current approaches to their solution are discussed.

The possibilities of modern atomistic simulation methods are considered using specific examples.

[1–8]

References [1] A.Ya. Freidzon, A.V. Scherbinin, A.A. Bagaturyants, M.V. Alfimov., J. Phys. Chem. A, 115, no. 18, (2011) 4565.

[2] V. Chashchikhin, E. Rykova, A. Scherbinin, A. Bagaturyants, Int. J. Quant. Chem., 112 (2012) 3110 [3] A. Bagaturyants , M. Alfimov, Atomistic Simulation of Hierarchical Nanostructured Materials for Optical Chemical Sensing.

Chemical Sensors: Simulation and Modeling, Vol. 4: Optical Sensors, Edited by G. Korotcenkov, Momentum Press, Ch. 1, 1.

[4] Vladimir Chashchikhin, Elena Rykova, and Alexander Bagaturyants, J. Phys. Chem. Letters, 4 (2013) 2298.

[5] Svetlana Emelyanova, Vladimir Chashchikhin and Alexander Bagaturyants, Chem. Phys. Lett., 590 (2013) 101.

[6] Andrei A. Safonov and Alexander A. Bagaturyants, J. Mol. Mod., 20 (2014) 2397.

[7] M. Bogdanova, S. Belousov, I. Valuev, A. Zakirov, M. Okun, D. Shirabaykin, V. Chorkov, P. Tokar, A. Knizhnik, B. Potapkin, A. Bagaturyants, K. Komarova, M.N. Strikhanov, A.A. Tishchenko, V.R. Nikitenko, V.M. Sukharev, N.A. Sannikova, I.V. Morozov, Procedia Computer Science, 29 (2014) 740.

[8] Ksenia A. Romanova, Alexandra Ya. Freidzon, Alexander A. Bagaturyants, Yury G. Galyametdinov, J. Phys. Chem. A.,.

nanoPT2015 Porto (Portugal)

| 25

Figures

Figure 1: Hierarchical levels of a functional material for optical chemical sensors.

Figure 2: Scheme of multiscale atomistic simulation of a functional material for optical chemical sensors.

26 | n a n o P T 2 0 1 5 P o r t o ( P o r t u g a l )

Bettencourt A1, Graça DF2, Ferreira IFS1, Matos A1, Louro H3, Silva MJ3, 1 1 Almeida AJ , Gonçalves LM 1 Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Lisbon - Portugal 2 REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Caparica, Portugal 3 Departamento de Genética Humana, Instituto Nacional de Saúde Dr. Ricardo Jorge, I.P. (INSA), Lisboa, Portugal

Does surface charge play a role in nanoparticulatesystems toxicity?

asimao@ff.ul.pt

When evaluating the toxicological effects of nanoand microparticulate-systems, it is of utmost importance to characterise the physicochemical properties that are likely to influence cell and tissue processes. In fact, specific physicochemical properties of materials at the nano- and microscale, such as size, charge or hydrophobicity can greatly differ from the ones of the bulk material and, thereby, can also drive unpredictable biological interactions and effects. In particularly, charge is one of the determinant properties of biological interaction and cationic particles have been shown to produce more effects on various cells than neutral or anionic particles [1].

The aim of the present work was to compare the toxicity of relevant biomedical acrylic based particulate systems (polymethylmethacrylate – PMMA), with different charges, within the same size range (≈500nm). Specifically, PMMA (negatively charged) and PMMA-Eudragit (positively charged) formulations were considered.

Both particles, hereinafter represented by PMMAp and PMMA-EUDp, were obtained by singleemulsion solvent-evaporation methodology [2].

The surface charge of particles was evaluated through zeta-potential measurement (Malvern Zetasizer Nano Z). Surface charge was measured in water dispersions, as well as in different media aiming to identify cell culture conditions, specifically ionic strength and FBS (fetal bovine serum) concentration, that would have a direct impact on particles charge.

Toxicological effects of both particulate systems were evaluated by cytotoxicity (MTT assay), stress response (H2DCFDA fluorescence test) and

genotoxicity (Comet assay) in fibroblast L929 cells (as recommended by [3]). To confirm cellular effects, uptake studies were also undertaken by confocal microscopy analysis.

Results showed a significant reduction in the absolute charge values of the particles with the increase in the ionic strength of the media. It should be pointed that at 0.12 M, which is the reported salt concentration in physiological solution, both particles showed a surface charge close to zero.

Also, results indicated that particles did not retain their original charge once they were put in contact with FBS. A complete inversion of PMMA-EUDp surface charge was observed when exposed to FBS, even at low concentrations (as low as 0.01%), while PMMAp surface charge tends to neutrality.

Concerning the evaluation of particles toxicological effects assessed by in vitro cellular assays, it was concluded that both particles were internalized in L929, after only 1h of exposure. Particles cytotoxicity, evaluated by the MTT, did not show any evidence of toxicity. Also, genotoxicity testing showed that PMMAp and PMMA-EUDp were not genotoxic in vitro, given that no significant induction in DNA damage was found through the comet assay for either particle type, as compared to negative controls. Furthermore, using FPG-modified comet assay, no significant oxidative DNA lesions occurred.

This absence of oxidative damage was confirmed with the H2DCFDA oxidative stress assay, since no significant rise in ROS was detected.

Overall, both PMMAp and PMMA-EUDp proved to be safe on the tested cell line and within the conditions employed on the various assays, showing promising biological properties for

nanoPT2015 Porto (Portugal)

| 27

potential use as carriers in drug-delivery applications. Considering that in the biological tested conditions none of the evaluated particles had positive charge, no conclusion could be made in what concerns comparing the toxicity of particles with opposite charge. Our study clearly shows that careful standardization of procedures must be undertaken, before evaluating potential biomedical application of particulate systems.

Acknowledgements: Work supported by the Portuguese government (Fundação para a Ciência e Tecnologia): research project EXCL/CTM-NAN/0166/2012 and strategic project PEst-OE/SAU/UI4013/2011.

References [1] Louro L, Bettencourt A, Gonçalves LM, Almeida AJ, Silva MJ. Role of nanogenotoxicology studies in safety evaluation of nanomaterials. In: S. Thomas, Y. Grohens, N. Ninan, ed.

Nanotechnology Applications for Tissue Engineering. Amesterdam: Elsevier. 2014 (In Press) [2] Bettencourt, A, Almeida, AJ. J Microencapsul.

29(4) (2012) 353-67.

[3] ISO 10993-5:2009: Biological evaluation of medical devices -- Part 5: Tests for in vitro cytotoxicity.

28 | n a n o P T 2 0 1 5 P o r t o ( P o r t u g a l )

Solution processing of graphene, related 2d crystals and hybrid structures for energy conversion and storage

Francesco Bonaccorso Istituto Italiano di Tecnologia, Graphene Labs, Genova, Italy francesco.bonaccorso@iit.it

Technological progress is driven by developments in material science. Breakthroughs can happen when a new type of material or new combinations of known materials with different dimensionality and functionality are created. Graphene, because of its many superior materials properties, has the opportunity to enable new products [1]. Graphene is just the first of a new class of two dimensional (2d) crystals, derived from layered bulk crystals [2].

The assembly of such 2d crystals (heterostructures) will provide a rich toolset for the creation of new, customised materials [1,2].

Energy conversion and storage are two of the grand challenges that our society is facing. New materials and processes [1] can improve the performance of existing devices or enable new ones [2,3,4,5] that are also environmentally benign. In this context, graphene and other 2d crystals are emerging as promising materials [1-5].

A key requirement for these applications is the development of industrial-scale, reliable, inexpensive production processes [2], while providing a balance between ease of fabrication and final material quality with on-demand properties.

Solution-processing [2] offers a simple and costeffective pathway to fabricate various 2d crystalbased energy devices, presenting huge integration flexibility compared to conventional methods.

Here I will present an overview of graphene and other 2d crystals-based energy conversion and storage applications, starting from solution processing of the raw bulk materials [2], the fabrication of large area electrodes [3] and their integration in the final devices [6,7,8].

References [1] A. C. Ferrari, F. Bonaccorso, et al., “Scientific and technological roadmap for graphene, related two-dimensional crystals, and hybrid systems�

Nanoscale DOI: 10.1039/c4nr01600a (2014).

[2] F. Bonaccorso, et al., Production and processing of graphene and 2d crystals. Materials Today, 15, 564-589, (2012).

[3] F. Bonaccorso, et. al., Graphene photonics and optoelectronics, Nature Photonics 4, 611-622, (2010).

[4] F. Bonaccorso, Z. Sun, Solution processing of graphene, topological insulators and other 2d crystals for ultrafast photonics. Opt. Mater.

Express 4, 63-78 (2014).

[5] G. Fiori, F. Bonaccorso, et al., Electronics based on two-dimensional materials.

Nature Nanotech 9, , 768-779, (2014).

[6] F. Bonaccorso, et. al., Graphene, related twodimensional crystals, and hybrid systems for energy conversion and storage. Science, 347, 1246501 (2015).

[7] J. Hassoun, F. Bonaccorso, et al. An advanced lithium-ion battery based on a graphene anode and a lithium iron phosphate cathode Nano Lett. 14, 4901-4906 (2014).

[8] P Robaeys, F Bonaccorso, et al. Enhanced performance of polymer: fullerene bulk heterojunction solar cells upon graphene addition. Appl. Phys. Lett. 105, 083306 (2014).

nanoPT2015 Porto (Portugal)

| 29

J. Borme1, G.M. Junior1, M.F. Cerqueira2, N. Vieira1,3, P. Alpuim1,2, 1 P.P. Freitas 1

INL – International Iberian Nanotechnology Laboratory, Av. Mestre José Veiga, Braga, Portugal 2 CFUM – Centre of Physics of the University of Minho, Campus de Gualtar, Braga, Portugal 3 IFSC – Physics Institute of São Carlos, University of São Paulo, São Carlos-SP, Brazil

Wafer-scale fabrication of solution-gated graphene field-effect transistors for biosensing applications

jerome.borme@inl.int

Graphene is a 2-dimensional material with a honeycomb structure formed by sigma bonds between three fourths of its valence electrons, the remaining fourth forming a huge conjugated electronic π system. Its transport properties are therefore extremely sensitive to the charge environment or to electric fields in its vicinity.

Graphene field-effect transistors (GFETs) take advantage of this fact which, together with the well-known density of states in the shape of Dirac cones close to the valence and conduction band edges, allows GFETs to be operated in n-, p- or ambipolar channel mode by shifting the Fermi level with the simple application of the appropriate gate voltage. Combining such electronic properties with a high chemical stability in biological and chemical solutions, graphene is a promising material for biosensing applications [1].

In order to detect specific biomarkers graphene surface must be functionalized with recognition biomolecules, such as antibodies [1]. For graphene-based devices to be usable in real applications it is necessary to process them at the wafer-scale. However, the integration of graphene with microelectronic devices has proven to be a difficult task due to poor adhesion of graphene to its insulating substrate after the transfer process using a temporary polymeric substrate, normally PMMA. This sets limits to the microfabrication processes that can be used to pattern devices on transferred graphene. The transfer of graphene on top of pre-patterned contacts, without need for further process, simplifies the fabrication.

Graphene produced over large areas by chemical vapor deposition (CVD) shows a high crystalline quality and almost 100% surface coverage which allows it to be used as an electric insulation layer in aqueous environment. This makes it possible to operate GFETs in solution-gated configuration (SG-

GFET), more suitable for biosensing than the traditional back-gated configuration due to a lower operational voltage [1, 2]. More important, the transistor transfer curve is highly sensitive to the liquid gate electrolytic properties, such as ionic strength, pH or any other parameter that changes the electrical double layer that forms at the solution-graphene interface.

Device Fabrication In this work, a 200 mm silicon wafer with 200 nm of thermal oxide and 3 nm of chromium as adhesion layer was covered with 30 nm of gold.

Using optical lithography and ion milling, the wafer was patterned with 126 devices (figure 1), each with source and drain contacts separated by a gap between 12.5 and 50 μm. An insulating layer of 320 nm of aluminium oxide was deposited on top of the contacts using a lift-off technique, leaving only 10 μm uncovered at the extremity of the contacts.

Copper foil of 25 μm thickness and 99.999% purity was cut into pieces with ≈20 mm side. These substrates were loaded into a quartz tube and heated to 1020 °C under low pressure argon flux.

Methane was introduced into the chamber, thermally decomposing to produce monolayer graphene on the copper catalyst. After deposition, the conventional copper dissolution process using PMMA as a temporary substrate was applied to the samples. The floating graphene/PMMA samples were then transferred onto different areas of the prepared wafer, such that graphene entirely covers the area of source and drain contacts, but does not short-circuit the source and drain pads. The PMMA temporary substrate was removed using acetone. The quality of graphene was assessed using Raman spectroscopy. The

30 | n a n o P T 2 0 1 5 P o r t o ( P o r t u g a l )

finished set of devices was characterized electrically at wafer-scale without further process.

Device Characterization Phosphate buffered saline (PBS, pH 7.4, 150 mM) solution was used in the measurements. A platinum (Pt) wire was used to gate the transistor through the solution. The experiments were conducted by dipping a known volume of PBS onto the graphene transistor sensing area.

Figure 2a shows the characteristic output curve at different gate voltages (VG = -0.2, 0 and 0.2 V). A linear behavior is observed, which is indicative of ohmic contacts between graphene and the contacts underneath.

The transfer curves of the devices show that the graphene is unintentionally p-doped. The p-doping is related to the process and the substrate (Figure 2b). Figure 2b shows that the transfer curve

changes with the ionic strength of the PBS (1X = PBS 150 mM) in such a way that the minimum conductivity point is shifted to lower VG when the ionic strength increases. This is consistent with the shorter Debye length in solutions with high ionic strength [1].

G.M.J thanks CNPq for a PhD grant. N.V is thankful to FAPESP for a post-doctoral grant.

References [1] Yan, F., Zhang, M., Li, J. Advanced Healthcare Materials 3 (2014) 313-331.

[2] Mao, S. et al. Scientific reports 3 (2013) 1-6

Figures

Figure 1: (left) Picture of the microfabricated 200 mm wafer with 130 sets of contacts for graphene devices and several graphene/PMMA pieces transferred. (top-right) Picture of the source and drain contacts (left and right respectively) in a device with a gap of 20 Îźm during the fabrication process (before graphene transfer) and an accessory insulated voltage line (not used in this work). (bottom-right) Picture of a device during a measurement with a platinum wire as a gate.

Figure 2: 2a (left) Output curves of the device for several VG values. 2b (right) Evolution of VG min as function of PBS ionic strength.

nanoPT2015 Porto (Portugal)

| 31

Joana Carrola1, Ivana Jarak1, Rui Silva1, António S. Barros2, Ana M. 1 1 Gil , M. Lourdes Pereira , M. Luisa 3 1 Corvo , Iola F. Duarte 1

CICECO, Departamento de Química, Universidade de Aveiro, Portugal 2 QOPNA, Departamento de Química, Universidade de Aveiro, Aveiro, Portugal 3 iMed.ULisboa,Departamento de Farmácia Galénica e Tecnologia Farmacêutica, Faculdade de Farmácia, Universidade de Lisboa, Lisboa, Portugal

Metabolic effects of silver nanoparticles assessed by NMR metabolomics of mice liver and serum

ioladuarte@ua.pt

Silver nanoparticles (Ag-NPs) are among the nanomaterials with highest propensity for human exposure, arising from their established use in wound dressings and increasing incorporation into consumer products (e.g. clothing, food packaging), mainly due to their remarkable antimicrobial properties. However, there is a narrow window between the bactericidal activity of Ag-NPs and their toxicity to human cells[1], making the further understanding of their biological effects a relevant up-to-date subject. Development of metabolic profiling (metabolomics) strategies for assessing the cellular and systemic effects of these nanoparticles may provide a unique and important tool that can be broadly applied in the areas of nanotoxicology and nanomedicine[2].

In this work, male mice were randomly divided into three groups, a control group (n 10) and two experimental groups (n 5 each) i.v. administered with Ag-NPs suspensions (1 mg/mL) and sacrificed at 24 and 48 hours post-injection. A complete necropsy was conducted on all mice. The necropsies included, but were not limited to, examination of the external surface, the cranial, thoracic, abdominal and pelvic compartments, including viscera. Liver, spleen, heart and kidneys were collected, rinsed with physiological serum and weighted. Tissue histopathology parameters and complete haemogram were also assessed. Based on a preliminary biodistribution study, liver tissues and blood serum were collected for metabolic profiling analysis. In particular, the 1 samples were analysed by H Nuclear Magnetic Resonance (NMR) spectroscopy, using High Resolution Magic Angle Spinning (HRMAS) for direct tissue analysis, and the spectral data subjected to multivariate analysis, namely Principal Component

Analysis (PCA) and Partial Least Squares Discriminant Analysis (PLS-DA), to highlight the metabolic differences between the groups.

The livers of control and Ag-NPs-exposed mice showed several significant differences in their metabolic composition, already apparent by 1 simple visual inspection of H HRMAS spectra (Figure 1A). Indeed, control and exposed groups showed a trend for separation in the PCA scores scatter plot and were clearly discriminated by PLSDA (Figure 1B). The main metabolic alterations explaining this separation were in the levels of glucose, glycogen and reduced glutathione (decreased in exposed animals compared to controls) and in the levels of choline compounds and taurine (increased in mice exposed to nanoparticles for 24 and 48h, respectively). In regard to serum NMR profiles, while the most apparent alterations were in the levels of lipoprotein subclasses (Figure 2A), several other differences could be found in small metabolites, including increased levels of amino acids (alanine, valine, lysine, histidine, tyrosine, phenylalanine), creatine, choline and glycerol, together with decreased levels of glucose, acetate and fumarate.

Interestingly, most of these changes showed a stronger magnitude at 24h than at 48h of Ag-NPs exposure, which explains the time-dependent group separation observed in the PCA and PLS-DA scores plots (Figure 2B). Overall, the results show that Ag-NPs, at a sublethal dose, disturb cellular and systemic metabolism, mainly affecting pathways involved in energy production and antioxidant protection.

32 | n a n o P T 2 0 1 5 P o r t o ( P o r t u g a l )

References [1] Kim S and Ryu DY, J. Appl. Toxicol., 33 (2013) 78.

[2] Duarte IF, J. Control. Release 153 (2011) 34.

Figures

Figure 1: (left) A) Average 1H HRMAS NMR spectra of liver tissue from control mice (top), and mice exposed to Ag-NPs for 24h (middle) and 48h (bottom). B) Scores scatter plots obtained by PCA and PLS-DA of NMR liver spectra (â—‹ controls; exposed 24h; exposed 48h).

Figure 2: A) Average 1H NMR spectra of blood serum from control mice (top), and mice exposed to Ag-NPs for 24h (middle) and 48h (bottom).

B) Scores scatter plots obtained by PCA and PLS-DA of NMR serum spectra (â—‹ controls; exposed 24h; exposed 48h).

nanoPT2015 Porto (Portugal)

| 33

Filomena A. Carvalho1, Ana Filipa Guedes1, Luís Sargento2, Nuno 2 3 Lousada , Carlos Moreira , Eduardo 3 Infante de Oliveira , J. Braz Nogueira3, Nuno C. Santos1 1 Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal 2 Hospital Pulido Valente, Centro Hospitalar Lisboa Norte, Lisbon, Portugal 3 Hospital de Santa Maria, Centro Hospitalar Lisboa Norte, Lisbon, Portugal

AFM as a nanotool to evaluate protein-cell interactions and cell-cell adhesion on cardiovascular pathologies

filomenacarvalho@medicina.ulisboa.pt

Increased levels of plasma fibrinogen result in changes in blood rheological properties, which are not completely clarified [1,2]. Erythrocyte aggregation has become an issue of increasing interest, especially as an indicator of the associated cardiovascular risk, since it is influenced mostly by fibrinogen levels [2-4]. A better understanding of the role of fibrinogen on erythrocyte aggregation in cardiovascular pathologies patients may be relevant for potential future drug interventions to reduce aggregation and enhance microcirculatory flow conditions. Our previous studies [5,6] demonstrated the existence of a single-molecule interaction between fibrinogen and a receptor on the erythrocyte membrane, with a lower but comparable affinity relative to platelet binding. The receptor identified is not as strongly influenced by calcium and eptifibatide (an αIIbβ3 specific inhibitor) as the platelet receptor. The results from Glanzmann thrombastenia (a rare hereditary bleeding disease caused by αIIbβ3 deficiency) patients showed, for the first time, an impaired fibrinogenerythrocyte binding. Correlation with genetic sequencing data demonstrated that one of the units of the fibrinogen receptor on erythrocytes is a product of the expression of the β3 gene. More recently, we also demonstrate that younger erythrocytes may be the main cells responsible for some cardiovascular diseases associated with an increase on the fibrinogen content in blood [7].

The aim of this study was to understand how fibrinogen influences erythrocyte aggregation by cell-cell adhesion force spectroscopy measurements using an atomic force microscope (AFM).

Additionally, we evaluated how this protein-cell

interaction constitutes a cardiovascular risk factor in different cardiovascular pathologies.

Cardiovascular patients with heart failure (HF; N=30), essential arterial hypertension (EAH; N=31) and aortic stenosis (N=25), as well as 15 healthy blood donors were engaged in this study. HF patients were grouped according to two etiologies: ischemic or non-ischemic HF. Fibrinogen-erythrocyte binding measurements were conducted by AFMbased force spectroscopy, in buffer, with the protein covalently attached to the AFM tip. Erythrocyteerythrocyte measurements were conducted only for healthy subjects, with one of the cells attached to AFM tipless cantilevers and the other on the solid substrate. Erythrocyte-erythrocyte adhesion forces were measured in the absence and in the presence of increasing fibrinogen concentrations.

Cell-cell adhesion data showed that increasing fibrinogen concentrations there is an increase in the work necessary for cell detachment, from 0.45 ± 0.04 fJ without fibrinogen to 12.0 ± 0.13 fJ at 1 mg/ml fibrinogen (p<0.001) (Figure 1A).

Concomitantly, average cell-cell detachment forces increase from 72.0 ± 2.9 pN without fibrinogen to 250.4 ± 3.2 pN at 1 mg/ml fibrinogen (p<0.001) (Figure 1B). We also observed a 3.5-fold increase on the number of membrane tethers per curve on the cell-cell detachment in the presence of fibrinogen 1 mg/ml, comparing with the experiments without fibrinogen. AFM data allow, for the first time, the quantification of the adhesion force necessary to detach two erythrocytes in the presence of different concentrations of fibrinogen. Our in vitro study tried to mimic what happens in vivo on the human blood flow. The results confirm that increasing fibrinogen

34 | n a n o P T 2 0 1 5 P o r t o ( P o r t u g a l )

plasma levels are associated with the higher tendency of erythrocytes to aggregate, probably by transient simultaneous binding of the protein to two cells, bridging them. This transient aggregation impairs blood flow and is associated with a higher risk of cardiovascular diseases.

conclude on the degree of pathophysiological relevance of fibrinogen and erythrocyte aggregation, since an increment on both might induce a state of microcirculatory slower flow, increasing the probability of cardiovascular complications.

References

Regarding the protein-cell interaction results, all cardiovascular patients presented significantly higher binding forces than healthy donors, despite lower binding frequency (Figure 2). HF ischemic patients presented higher forces than the nonischemic ones (74.9 ± 10.7 pN vs. 45.4 ± 5.6 pN; p=0.021). Fibrinogen-erythrocyte interactions were higher in all cardiovascular patients than the control group. This could lead to changes on whole blood flow, representing a cardiovascular risk factor. EAH patients seem to have a higher cardiovascular risk dependent of the increase of fibrinogen plasma concentration levels. The results are relevant to

[1] Delamaire and Durand, J Mal Vasc 15 (1990) 344-345 [2] Falcó et al., Clin Hemorheol Microcirc 33 (2005) 145-151 [3] Kwaan, Clin Hemorheol Microcirc 44 (2010)167176 [4] Pretorius and Kell, Integr Biol 6 (2014) 486-510 [5] Carvalho et al., ACS Nano 4 (2010) 4609-4620 [6] Carvalho and Santos, IUBMB life 64 (2012) 465-72 [7] Carvalho et al, Plos One 6 (2011) e18167

Figures

Figure 1: Cell-cell adhesion studies. Erythrocyte-erythrocyte adhesion in the absence and in the presence of increasing fibrinogen concentrations, measured by AFM-based force spectroscopy. Quantification of the work (A) and the detachment force (B) necessary to break the interaction.

Figure 2: AFM-based force spectroscopy data of the interactions between fibrinogen and erythrocytes from patients with different cardiovascular pathologies, and healthy blood donors (control subjects). Average values of force (A), and percentage of (un)binding events (B) for all groups of patients and control. Data indicates that all groups of patients – heart failure (HF), essential arterial hypertension (EAH) and aortic stenosis – have an increase on the force of the binding between fibrinogen and erythrocyte, despite their decrease on (un)binding frequency (probability).

nanoPT2015 Porto (Portugal)

| 35

J. D. Costa1,2, E. Paz1, J. Borme1, S. Serrano1, J. M. Teixeira2, J. Ventura2, R. 1 1,3 Ferreira , P. P. Freitas 1

International Iberian Nanotechnology Laboratory, INL, Braga, Portugal 2 IN-IFIMUP, Porto, Portugal 3 INESC-MN and IN- Institute of Nanoscience and Nanotechnology, Lisbon, Portugal

Nanofabrication of Magnetic Tunnel Junction Pillars Targeting Nano-Oscillator Applications

diogo.costa@visitor.inl.int

Magnetic Tunnel Junctions are Spintronic devices constituted by two ferromagnetic layers separated by a nanometric insulating barrier. The theoretical predictions of giant Tunnel Magnetoresistance (TMR) values in fully crystalline Fe(001)/MgO(001)/Fe(001) structures [1] were soon followed by its experimental verification [2,3]. Such giant TMR effect arises from the conservation of the coherence of the electron wave function during tunneling across crystalline MgO and from the smaller decay rate of the spin up states in the barrier when compared to that of spin down states (spin filtering effect) [4]. In state of the art CoFeB-MgO MTJs, TMR ratios of up to 600% have been reported [5]. In the low resistance x area (RA) range, which is the most important for applications, TMR values of 138% have been demonstrated in MTJs with 2 RA~2.4 Ωμm (in unpatterned MTJs) [6].

These results promptly widened the prospect of fabricating novel magnetic devices that operate using spin transfer torque (STT) mechanisms. This effect consists in the transfer of the moment of magnetic spins from a polarized electrical current to the ferromagnetic layers, thus allowing the manipulation of the magnetization of nano-magnets by means of local currents in opposition to magnetic fields. Two of the best positioned STT applications to reach the commercialization in the short term are RF emitters resulting from persistent magnetic dynamics driven by DC currents and non-volatile magnetic random access memories.

In order to achieve high quality STT devices the downscaling of MTJs until dimensions below 100 nm is necessary. In this presentation we will describe our nanofabrication process which is mainly based in e-beam lithography and ion milling steps. Several problems arise from the miniaturization of the MTJs being one of the most prominent the material re-

deposition on the sidewalls of the nanopillars during the ion beam etching. This re-deposition inflates the final device critical dimension. More importantly, it causes the electrical shunting across the barrier which decreases the TMR. To remove the material re-deposition a low angle milling is usually used after the normal milling definition. However, low angle millings create damages in the device edges, generate shadowing effects that prevent the formation of vertical sidewalls and decrease the process uniformity due to clamps used at wafer edges. The edge damage can be minimized by using a low beam energy milling. However, the divergence of the beam increases for lower beam energies and thus a compromise must be found. Another problem related to the nanofabrication process consists in conferring mechanical stability to the devices while keeping the nanopillars open on top. This structure enables the microfabrication of the remaining components of the device that allow the reading/writing of the MTJ. To achieve this structure a dielectric material is deposited after the nanopillar definition and afterwards opened on the top of the pillars. In order to open the MTJs, processes based on lift-off and chemical-mechanical processes (CMP) have been used. Despite the simplicity of the lift-off process, the yield of the open nanopillars is relatively low and it has a process time that can go up to two weeks. Moreover, the process is intrinsically worse for smaller nanopillars. As for the CMP process, it is a very fast process that opens more easily the smaller pillars. However, there are a lot of residues arising from the planarization and a good uniformity is difficult to achieve.

Here, we also propose the use of an ion beam planarization step after the nanopillar definition.

This process is faster than the lift off and cleaner that CMP and intrinsically better for the smaller pillar sizes. Using the described process we were

36 | n a n o P T 2 0 1 5 P o r t o ( P o r t u g a l )

2

able to achieve MTJs with RA below 1.5 Ωμm and TMR up to 130%. We will also give a general overview of the different devices fabricated, such as the double barrier MTJs, magnetic vortexes and MTJs with perpendicular magnetic anisotropy.

References [1] Spin-dependent tunneling conductance of Fe/MgO/Fe sandwiches, W.H. Butler, X.-G. Zhang, T.C. Schulthess, and J.M. MacLaren, Phys. Rev. B 63, 054416 (2001), [2] Giant tunnelling magnetoresistance at room temperature with MgO (100) tunnel barriers, S.S.P. Parkin, C. Kaiser, A. Panchula, P.M. Rice, B. Hughes, M. Samant, and S.-H. Yang, Nat. Mater. 3, 862 (2004), [3] Giant room-temperature magnetoresistance in single-crystal Fe/MgO/Fe magnetic tunnel junctions, S. Yuasa, T. Nagahama, A. Fukushima, Y. Suzuki, and K. Ando, Nature Mater. 3, 868 (2004), [4] Giant tunnel magnetoresistance in magnetic tunnel junctions with a crystalline MgO(0 0 1) barrier, S. Yuasa and D.D. Djayaprawira, J. Phys. D 40, R337 (2007), [5] Tunnel magnetoresistance of 604% at 300 K by suppression of Ta diffusion in CoFeB/MgO/CoFeB pseudo-spin-valves annealed at high temperature, S. Ikeda, J. Hayakawa, Y. Ashizawa, Y.M. Lee, K. Miura, H. Hasegawa, M. Tsunoda, F. Matsukura, and H. Ohno, Appl. Phys. Lett. 93, 082508 (2008).

[6] In situ heat treatment of ultrathin MgO layer for giant magnetoresistance ratio with low resistance area product in CoFeB/MgO/CoFeB magnetic tunnel junctions, S. Isogami, M. Tsunoda, K. Komagaki, K. Sunaga, Y. Uehara, M. Sato, T. Miyajima, M. Takahashi, Appl.

Phys. Lett. 93, 192109 (2008).

nanoPT2015 Porto (Portugal)

| 37

Nitin M. Batra, Shashikant Patole, Ziwei Fan, Pedro M. F. J. Costa Physical Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia

The structure and chemistry of CNTs in electrical nanodevices fabricated by beam deposition

pedro.dacosta@kaust.edu.sa

Despite the progress of the last two decades [1], the characterization of carbon nanotubes (CNT) at the individual structure level remains a non-trivial task [2]. In regards to the fabrication of electrical nanodevices, questions remain on the effect of using beam deposition methods [3]. Amongst others, the extent of modification of the CNT lattice, as well as the deposition tail of the patterned electrodes, are issues that have attracted little attention. Further to this, the structural and chemical nature of the deposited contacts is a subject not fully understood.

Figures

Using a plasma-enhanced chemical vapor deposition reactor, a mat of vertically aligned multi-walled CNT (MWCNT) were grown (Fig. 1a). The nanotubes were then characterized with electron microscopy (Fig. 1b) and Raman spectroscopy. After dispersing them in solution, the nanotubes were drop-casted onto patterned Si/SiO2 substrates and Pt electrodes deposited by either ion or electron beam methods (Fig. 1c). Besides characterizing the individual MWCNTs electrically, their structural and chemical integrities near the contact areas were analyzed.

Assessment performed clearly showed beam deposition contamination of the nanotube interconnect along its length. Remarkably, there seems to be little mention of this critical issue in the literature.

References [1] De Volder, M. F. L.; Tawfick, S. H.; Baughman, R. H.; Hart, A. J. Carbon Nanotubes: Present and Future Commercial Applications. Science 339 (2013) 535.

[2] Costa, P. M. F. J.; Gautam, U. K.; Bando, Y.; Golberg, D. Direct imaging of Joule heating dynamics and temperature profiling inside a carbon nanotube interconnect. Nature Communications 2 (2011) 421.

[3] Murakami, K.; Matsubara, N.; Ichikawa, S.; Kisa, T.; Nakayama, T.; Takamoto, K.; Wakaya, F.; Takai, M.; Petersen, S.; Amon, B. et al. Transmission-ElectronMicroscopy Observation of Pt Pillar Fabricated by Electron-Beam-Induced Deposition. Japanese Journal of Applied Physics 48 (2009) 06FF12.

Figure 1: a) As-grown sample of vertically aligned MWCNT; b) View of the internal bamboo-shaped structure of the nanotubes; c) Fourterminal electrical device of an isolated nanotube.

38 | n a n o P T 2 0 1 5 P o r t o ( P o r t u g a l )

Fernando J.A.L. Cruz, José P.B. Mota

Thermodynamics of DNA Strands Encapsulated into Electrically Charged Nanotubes

Requimte/CQFB, Dept. Chemistry, Universidade Nova de Lisboa, Caparica, Portugal fj.cruz@fct.unl.pt

I. Introduction. Deoxyribonucleic acid (DNA) and single-walled carbon nanotubes (SWCNTs) are prototypical one-dimensional structures; the former plays a central role in chemical biology and the latter holds promise for nanotechnology applications [13]. From the point of view of biological purposes and DNA manipulation, carbon nanotubes have been proposed as templates for DNA encapsulation, intracellular penetration via endocytosis and delivery of biological payloads. Their interactions have been the subject of intense investigation, nonetheless, the corresponding molecular-level phenomena remain rather unexplored. Recently we have shown that, given a sufficiently large hydrophobic nanotube, the confinement of a DNA dodecamer is thermodynamically favourable under physiological environments (134 mM, 310 K, 1 bar), leading to DNA-nanotube hybrids with lower free energy than the unconfined biomolecule [4]. To accommodate itself within the D = 4nm nanopore, DNA’s end-to-end length increases from 3.85 nm up to approximately 4.1 nm, via a 0.3 nm elastic expansion of the strand termini. The canonical Watson-Crick H-bond network is essentially preserved throughout encapsulation, showing that contact between the DNA dodecamer and the hydrophobic carbon walls results in minor rearrangements of the nucleotides H-bonding. A diameter threshold of 3 nm was established below which encapsulation is inhibited. It is known that nanotubes can be electrically charged, either using an AFM tip and applying a voltage bias or by chemically doping the solids with p-type dopants to obtain positively charged nanotubes [5, 6]. The effect of charge density upon the energetics and dynamics of confinement needs to be addressed; because DNA’s outer surface is negatively charged (phosphate moieties), its interaction with a positively charged solid might lead to the occurrence of encapsulation which is inhibited for hydrophobic pores. We address this issue using enhanced sampling algorithms to probe the encapsulation mechanism of an atomistically detailed DNA

–

molecule, onto positively charged (q = + 0.05 e /C) SWCNTs of different diameters (3 nm, 4 nm), while employing precise physiological conditions.

II. Results & Discussion. In contrast with the purely hydrophobic (40,0) topology (D = 3 nm), the existence of an overall positive charge density on the solid indeed favours the encapsulation of the DNA molecule. To probe the thermodynamical stability associated with encapsulation, free-energy landscapes are built using the well-tempered metadynamics scheme [7] and two order parameters relating the distance between centres of mass of DNA and SWCNT, ξ1, and the end-to-end length of the biomolecule, ξ2. The corresponding free-energy maps recorded in Fig.1 show that: i) the nanopore endohedral volume (ξ1 <2) is the thermodynamically preferred region, by comparison with the bulk (ξ1 >2), ii) encapsulated DNA retains its translational mobility, diffusing freely between adjacent free-energy minima located within the solid and iii) whilst DNA maintains a quasi B-form end-to-end length within the (51,0) topology (D = 4 nm), the double-strand seems to suffer an elastic contraction when subjected to such a constraining volume as a (40,0) nanotube. The end-to-end length, L, probability distributions, P(Ω2), have been determined by independent umbrella sampling calculations and the results are recorded in Fig.2 for both topologies, (40,0) and (51,0), along with the previous results obtained for a purely hydrophobic (51,0) SWCNT [4].

It now becomes clear that charge density on the solid plays a paramount role upon the encapsulation mechanism; the elastic expansion of the doublestrand observed for the (51,0) hydrophobic pore (L = 4.1 nm) is annihilated when the solid becomes electrically charged resulting in a maximum probability DNA end-to-end length of L = 3.73 nm, consistent with the canonical B-DNA form [8]. On the other hand, to accommodate itself within the constricting volume of the (40,0) topology, the DNA molecule undergoes a contraction and exhibits a maximum probability of occurrence at L = 3.54 nm.

nanoPT2015 Porto (Portugal)

| 39

A nanoscopic picture of the encapsulated DNA molecule can be produced by calculating the corresponding number density maps, as indicated in Fig.3 and obtained from atomically detailed mass histograms. Fig.3 reveals the existence of a cylindrical exclusion volume centred along the (51,0) main axis, where molecular density is Ď â&#x2030;&#x2C6; 0, which can be attributed to the strong electrostatic 3â&#x2C6;&#x2019; attraction between DNA ( PO4 ions) and the solid, driving the former towards the walls and away from the nanopore center. Entropic effects caused by the pore narrowness of the (40,0) SWCNT force the DNA molecule to cluster tightly around the nanopore center, where it exhibits the region of highest molecular density.

As far as we are aware these observations are the first of their kind, and they come to pave the way for the design of smart nanotube based devices for in vivo DNA encapsulation.

Figures

Figure 1: Free energy landscapes of DNA@SWCNT hybrids. Ξ1 is the distance between centres of mass of the DNA and SWCNT, projected along the nanopore main axis, and Ξ2 is the absolute distance between (GC) termini on opposite sides of the doublestrand, equivalent to the DNA end-to-end length. The several freeenergy minima along Ξ1 demonstrate that the molecule is relatively mobile to translocate along the nanotube; interestingly, all the Ξ1 minima are located along a quasi-linear path defined by Ξ2 â&#x2030;&#x2C6; 3.7 nm (40,0) and Ξ2 â&#x2030;&#x2C6; 4 nm (51,0) highlighting the enhanced thermodynamical stability corresponding to the canonical B form under the (51,0) topology.

Acknowledgements The authors would like to acknowledge Requimte/CQFB for generous CPU time. This work makes use of results produced with the support of the Portuguese National Grid Initiative (more information in https://wiki.ncg.ingrid.pt). F.J.A.L. Cruz gratefully acknowledges financial support from FCT/MCTES (Portugal) through grants EXCL/QEQPRS/0308/2012 and SFRH/BPD/45064/2008.

Figure 2: Potential of mean force and probability distribution profiles. Ί2 corresponds to the end-to-end length of DNA. Symbols are umbrella sampling results and red lines are free fittings of data to Gaussian

statistics,

Ί â&#x2C6;&#x2026;exp Ί

:

blue)

DNA@(40,0) SWCNT, black) DNA@(51,0) SWCNT, green) DNA@(51,0) hydrophobic SWCNT [4].

References [1] H. Kumar et al., Soft Matter 7 (2011) 5898.

[2] B.M. Venkatesan and R. Bashir, Nature Nano. 6 (2011) 615.

[3] A.D. Franklin et al., Nano Lett. 12 (2012) 758.

[4] F.J.A.L. Cruz et al., J. Chem. Phys. 140 (2014) 225103.

[5] X. Zhao and J.K. Johnson, J. Am. Chem. Soc. 129 (2007) 10438.

[6] F.J.A.L. Cruz et al., RSC Advances 4 (2014) 1310.

[7] A. Barducci et al., Phys. Rev. Lett. 100 (2008) 020603.

[8] J.M. Vargason et al., Proc. Nat. Acad. Sci. 98 (2001) 7265.

Figure 3: Number density maps of DNA@SWCNT. The existence of a cylindrical exclusion volume centred along the (51,0) nanopore main axis, Ď â&#x2030;&#x2C6; 0, is the direct consequence of strong electrostatic attractions between the heavily charged phosphate groups and the solid. The dashed lines indicate the boundaries of the nanotube.

40 | n a n o P T 2 0 1 5 P o r t o ( P o r t u g a l )

Eunice Cunha1, M. Conceição Paiva1, M. Fernanda Proença2, Rui Araújo2

Exfoliation of graphite using pyrene and perylene derivatives

1 Instituto de Polímeros e Compósitos/I3N, Universidade do Minho, Campus de Azurém, Guimarães, Portugal 2 Centro de Química, Universidade do Minho, Campus de Gualtar, Braga, Portugal

eunice.cunha@dep.uminho.pt

Since the isolation of graphene by mechanical exfoliation of graphite in 2004 [1] this material has been the focus of research among the scientific community. The excellent electronic, mechanical, thermal and optical properties of graphene [2] have reveled huge potential applications in various fields such as energy storage [3,4], composite materials [5] and sensor technology [6]. However, the production of graphene in large scale, with controlled quality and reasonable cost, is still a goal to achieve and became an important target and research topic.

Visible spectroscopy. The graphene-based materials deposited on surfaces were analyzed by Raman spectroscopy, showing the effectiveness of the exfoliation of pristine graphite. TEM images of the suspensions illustrate the formation of few layer graphene. Figure 1a presents the Raman spectra of graphite and few-layer graphene obtained by exfoliation with a pyrene derivative (Py-XGnP), and Figure 1b illustrates the TEM observation of the PyXGnP. Acknowledgements

The large scale graphene production processes are based on the conversion of SiC (silicon carbide) to graphene via sublimation of silicon at high temperature, chemical vapor deposition (CVD) growth, oxidation of graphite followed by exfoliation and reduction of the oxidation products, and exfoliation of graphite in organic solvents with high surface tension. These methods lead to large scale production, but present some disadvantages namely the high cost, or the production of graphene with structural defects or contaminants which are difficult to remove [7].

We gratefully acknowledge FCT for PhD grant SFRH/BD/87214/2012 and Post-doc grant SFRH/BPD/88920/2012.

Some aromatic compounds such as pyrene and perylene derivatives, functionalized to render them amphiphilic, have been reported to effectively stabilize carbon nanotubes in aqueous suspensions [8,9]. Recently, the production of graphene based on graphite exfoliation through non-covalent interactions between graphene/pyrene and graphene/perylene derivatives was also reported [10]. This approach promotes the exfoliation and stabilization of graphene in water, leading to the production of few- and single- layer graphene without damaging its structure.

The present work reports the preparation of stable aqueous suspensions of few-layer graphene using low concentration solutions of pyrene and perylene derivatives. The suspensions were analyzed by UV-

nanoPT2015 Porto (Portugal)

| 41

References [1] K. Novoselov, A. Geim, S. Morozov, D. Jiang, Y. Zhang, S. Dubonos, I. Grigorieva and A. Firsov, Science, 306 (2004) 666-669.

[2] A. Geim and K. Novoselov, Nature Materials, 6 (2007) 183-191.

[3] M. Stoller, S. Park, Y. Zhu, J. An and R. Ruoff, Nano Letters, 8 (2008) 3498-3502 [4] S. Ghosh, X. An, R. Shah, D. Rawat, B. Dave, S. Kar, S.Talapatra, Physical Chemistry C, 116 (2012) 20688−20693.

[5] H. Kim, A. Abdala and C. Macosko, Macromolecules, 43 (2010) 6515–6530.

[6] X. Zhang, F. Gao, X. Cai, M. Zheng, F. Gao, S. Jiang and Q. Wang, Materials Science and Engineering C, 33 (2013) 3851–3857.

[7] V. Singh, D. Joung, L. Zhai, S. Das, S. Khondaker and S. Seal, Progress in Materials Science, 56 (2011) 1178–1271.

[8] T. Fujigaya and N. Nakashima, Polymer Journal, 40 (2008) 577–589.

[9] R. Araújo, C. Silva, M. C. Paiva, M. Melle Franco and M. F. Proença, RSC Advances, 3 (2013) 24535-24542.

[10] D. Parviz, S. Das, H. Ahmed, F. Irin, S. Bhattacharia, and M. Green, ACS Nano, 6 (2012) 8857–8867

Figures

Intensity (a.u.)

a)

Py – XGnP

XGnP 1000 b)

1500

2000

2500

3000

-1

Raman Shift (cm )

Figure 1: a) Raman spectra of pristine graphite (XGnP) and exfoliated graphite using pyrene derivative (Py-XGnP); b) TEM image of Py-XGnP (on the left), magnified TEM Image (on the right) and XRD pattern of magnified Py-XGnP TEM image

42 | n a n o P T 2 0 1 5 P o r t o ( P o r t u g a l )

J. A. Lawlor and M. S. Ferreira

Sublattice asymmetry of substitutionally doped impurities in graphene

School of Physics and CRANN, Trinity College Dublin, Dublin, Ireland ferreirm@tcd.ie

Motivated by the recently observed sublattice asymmetry of substitutional nitrogen impurities in CVD grown graphene, we show, in a mathematically transparent manner, that oscillations in the local density of states driven by the presence of substitutional impurities are responsible for breaking the sublattice symmetry. While these oscillations are normally averaged out in the case of randomly dispersed impurities, in graphene they have either the same, or very nearly the same, periodicity as the lattice. As a result, the total interaction energy of randomly distributed impurities embedded in the conduction-electronfilled medium does not vanish and is lowered when their configuration is sublattice-asymmetric. We also identify the presence of a critical concentration of nitrogen above which one should expect the sublattice asymmetry to disappear. This feature is not particular to nitrogen dopants, but should be present in other impurities.

nanoPT2015 Porto (Portugal)

| 43

Quirina Ferreira1, Ana Margarida Bragança1, A.M. Ferraria2, A.M. Botelho do Rego2, Luís Alcácer1, 1,3 Jorge Morgado 1

Instituto de Telecomunicações, Lisboa, Portugal 2 Centro de Química-Física Molecular and Institute of Nanoscience and Nanotechnology, Inst. Sup. Tecn., Universidade de Lisboa, Lisbon, Portugal 3 Department of Bioengineering, Instituto Superior Técnico, Lisboa, Portugal

Biocompatible and nanostructured monolayers on graphite for drug delivery applications

quirina.ferreira@lx.it.pt

The development of new nanostructured coatings with biomedical applications has been receiving greater attention in recent years due to the ability to give them specific and versatile functions by controlling their architecture. Stepwise methods, based on self-assembly properties of molecules, can provide a simpler and reproducible solution to prepare supramolecular structures with molecular control. The scanning tunneling microscope (STM) is a versatile tool to fabricate and control the molecular assemblies at the nanoscale. In particular, when operated at the solid/liquid interface, by placing a solvent droplet between the STM tip and the substrate, it is possible to add molecules in order to create organized structures [1-3].

We have been applying a stepwise method to built nanostructured and biocompatible monolayers composed of glycosaminoglycans adsorbed on Highly Oriented Pyrolitc Graphite (HOPG). The idea is to functionalize graphite with biomolecules that can act as anchor points to adsorb nanocarriers used in drug delivery. Figure 1 shows a monolayer composed of glucuronic acid (AcGl) and 1-heptanoic acid (AcHept).

Both molecules were added to graphite at the same time and their adsorption was monitorired using STM at solid/liquid interface [1-3]. Theoretical simulations and X-ray photoelectron spectroscopy (XPS) showed that the stability of the monolayer is controlled by the H-bond interactions between the two acids. High resolution STM images show the formation of AcGl dimmers separated by lamellas with planar AcHept.

At moment, we are using these monolayers to absorb an alpha-2-adrenergic receptor agonist encapsulated in a cyclodextrin. Drug release kinetic studies monitored by UV-spectroscopy are underway and preliminary results suggest that this monolayer is very stable and that it is possible to control the drug release in function of time.

Acknowledgements We thank FCT-Portugal, under the project PEstOE/EEI/LA0008/2014 and PostDoc grants SFRH/BPD/75338/2010, for financial support.

References [1] Q. Ferreira, Ana Margarida Bragança, L. Alcácer, J. Morgado, “Conductance of well-defined porphyrin self-assembled molecular wires up to 14 nm in length”, Journal of Physical Chemistry C, 118 (3), 7229 - 7234, 2014.

[2] Q. Ferreira, A. M. Bragança, N. M. M. Moura, M. A. F. Faustino, L. Alcácer, J. Morgado, “Dynamics of porphyrin adsorption on highly oriented pyrolytic graphite monitored by scanning tunnelling microscopy at the liquid/solid interface”, Applied Surface Science, 273, 220, 2013.

[3] Q. Ferreira, L. Alcácer, J. Morgado, “Stepwise Preparation and Characterization of Molecular Wires made of Zinc octaethylporphyrin complexes bridged by 4,4’-bipyridine on HOPG”, Nanotechnology, 22, 435604, 2011.

Figures

Figure 1: STM image (V=0.78V, It=0.42 nA) showing a lamellar structure of a self-assembled monolayer formed by co-adsorption of glucuronic acid and 1-heptanoic acid.

44 | n a n o P T 2 0 1 5 P o r t o ( P o r t u g a l )

Fábio G. N. Figueiras1,2, Igor K. Bdikin3, Vitor B. S. Amaral1, Andrei L. Kholkin4 1 Physics Dep. & CICECO, Aveiro University, Aveiro, Portugal.

2 IFIMUP-IN, Sciences Faculty, Porto University, Porto, Portugal 3 Mechanics Eng. Dep. & TEMA, Aveiro University, Aveiro, Portugal.

4 Materials Eng. Ceramics Dep. & CICECO, Aveiro University, Aveiro, Portugal

Nanometric Bias Induced Phase Transitions in materials

ffigueiras@ua.pt

We present a research that opens a new pathway for the production of microelectronic chips like sensors, transducers and memory. This technology enables to imprint nano scale (re)programmable multifunctional electronic devices from a single material basis.

References [1] F. G. N. Figueiras, I. K. Bdikin, V. B. S. Amaral, A. L. Kholkin, “Local bias induced ferroelectricity in manganites with competing charge and orbital order states”, Phys.Chem.Chem.Phys., (2014), 16, 4977

By means of Surface Probe Microscopy (SPM) methods, namely suitable bias lithography stimulation and piezo response mode, it is possible to induce localized electrochemical states and stabilize local nanometric CO/OO regions which exhibit clear electric/magnetic/structural functional responses in contrast with the original matrix material properties. The mechanism that underlie such versatile phenomena is based on a set of SCE materials (strong correlated electron systems) having specific compositions near the threshold of relevant phase transitions, that drastically alter some structural, electric or magnetic transport properties and while enabling the concomitance of the distinct phases in nonometric regions [1].

Figures

Figure 1: Consistent asymmetric effects of + or – bias poling are demonstrated in local SPM measurements of current versus voltage (left) and piezoresponse (right). Positive bias enhances electric conductivity while negative bias pooling sets a dielectric state and enables to observe piezoelectric loops.

nanoPT2015 Porto (Portugal)

| 45

Elvira Fortunato, Lidia Santos, Daniela Salgueiro, Rita Branquinho, Pedro Barquinha, Luis Pereira, Rodrigo Martins Departamento de CiĂŞncia dos Materiais, CENIMAT/i3N, Faculdade de CiĂŞncias e Tecnologia - Universidade Nova de Lisboa and CEMOP/Uninova, Caparica, Portugal

A review on metal oxide semiconductors applied to transistors: from nanofilms to nanoparticles

emf@fct.unl.pt

In this work we will review some of the most promising new technologies for n- and p-type thin film transistors based on oxide semiconductors either in the form of nano-films or nanoparticles, with special emphasis to solution-processed, and we will summarize the major milestones already achieved with this emerging and very promising technology focused on the work developed in our laboratory.

Transparent electronics has arrived and is contributing for generating a free real state electronics that is able to add new electronic functionalities onto surfaces, which currently are not used in this manner and where silicon cannot contribute [1,2]. The already high performance developed n- and p-type TFTs have been processed by physical vapour deposition (PVD) techniques like rf magnetron sputtering at room temperature which is already compatible with the use of low cost and flexible substrates (polymers, cellulose paper, among others). Besides that a tremendous development is coming through solution-based technologies very exciting for ink-jet printing, where the theoretical limitations are becoming practical evidences. In this presentation we will review some of the most promising new technologies for thin film transistors based on oxide semiconductors and its currently and future applications.

Figures

Figure 1: High resolution FIB-SEM cross-section images and transfer characteristics of bottom gate TFTs produced with solution based GZTO and water-based AlOx.

References [1] E. Fortunato, P. Barquinha, and R. Martins, "Oxide Semiconductor Thin-Film Transistors: A Review of Recent Advances," Advanced Materials, vol. 24, pp. 2945-2986, Jun 2012.

[2] P. Barquinha, R. Martins, L. Pereira and E. Fortunato, Transparent Oxide Electronics: From Materials to Devices. West Sussex: Wiley & Sons (March 2012). ISBN 9780470683736.

46 | n a n o P T 2 0 1 5 P o r t o ( P o r t u g a l )

A.Ya. Freidzon, A.A. Safonov, A.A. Bagaturyants Photochemistry Center, Russian Academy of Sciences, Moscow, Russia freidzon.sanya@gmail.com

Spectral and Transport Parameters of ElectronTransporting Material Bis(10-hydroxybenzo[h]qinolinato)beryllium (Bebq2)

(Bis(10-hydroxybenzo[h]quinolinato)beryllium (Bebq2) is an electron-transporting and fluorescent material used in organic light-emitting diodes. It exhibits excellent emitting and charge-transport characteristics. In this work we present the results of quantum-chemical calculations of Bebq2 molecule and its dimers in order to better understand the mechanism of charge transport in this material and its luminescence properties.

We use multireference XMCQDPT2/CASSCF method to calculate the reorganization energies and hopping integrals for electron and hole transport in various dimers of Bebq2 that can occur in the solid phase as well as their absorption spectra. The same method is used to calculate the ionization potential, electron affinity and absorption and emission spectra of Bebq2 monomer.

The key feature in small-molecular organic semiconductors is charge localization. Our technique can directly show, whether the charge carrier is localized or delocalized depending on the arrangement of monomers in dimer. In this respect, our technique is superior to the energy splitting in dimer (ESID) method commonly used for calculating hopping integrals in organic semiconductors.

The potential energy profiles for electron and hole hopping in different dimers are constructed to explain different hopping rate for electrons and holes. The calculated spectra of dimers exhibit exciton splitting that ensures low emission intensity.

Our computational results agree well with the experiment.

Figures

O

N

Figure 1: Chemical structure of Bebq2 molecule

Be O

N

位

Charge on A

Charge on B

Charge transfer coordinate

Figure 2: Reorganization energy 位 and hopping integral HAB in Bebq2 dimer.

2|HAB| Hopping barrier Charge on A

Charge on B

Charge transfer coordinate

nanoPT2015 Porto (Portugal)

| 47

Iúri Frias, Marina Pinheiro and Salette Reis REQUIMTE, Departamento de Ciências Químicas, Laboratório de Química Aplicada, Faculdade de Farmácia da Universidade do Porto, Rua de Jorge Viterbo Ferreira, Portugal bio08056@fe.up.pt

Green tea is manufactured from the leaves of Camellia sinensis, and has been regarded to possess, anti-cancer, anti-obesity, anti-atherosclerotic, antidiabetic, anti-bacterial, and anti-viral effects. The beneficial effects of green tea are atributed to the presence of the polyphenol (-)-epigallocatechin gallate (EGCG) (Fig. 1). EGCG has a stability dependent of the pH, temperature, and oxygen levels [1]. In this context, the encapsulation of EGCG in nanoparticles is an effective method to protect EGCG from adverse gastrointestinal conditions and to enhance its absortion. In this study, EGCG-loaded solid lipid nanoparticles (SLN) and nanostructured lipid carriers (NLC) nanocarrier systems were designed, developed and characterized. The lipid nanocarriers were synthetized to be biocompatible, and to improve the stability and bioavailability of EGCG for oral supplementation. The developed EGCG nanosystems revealed high encapsulation efficiency (approximately 80%), a sustained release in gastrointestinal environment and low cytotoxicity in the intestinal Caco-2 cellular lines. The developed nanocarriers-based EGCG delivery system can be exploited as a supplement and nutraceutical for the prevention and treatment of several diseases based on the supplementation of EGCG.

Development of lipid nanocarriers-based epigallocatechin gallate for preventive and therapeutic supplementation

References [1] Wang, D.; Taylor, W.; Wang, Y.; Wan, X.; Zhang.

J. International Journal of Nanomedicine, (2012) 1711-21.

Figures

Figure 1: Chemical structure of EGCG

48 | n a n o P T 2 0 1 5 P o r t o ( P o r t u g a l )

Fu Guo-Dong and Yao Fang School of Chemistry and Chemical Engineering, Southeast University, Jiangning District, Nanjing, Jiangsu Province, P.R. China

Among various fluorescence imaging technology, the near infrared (NIR) fluorescence imaging is expected to have significant impact on future personalized oncology therapy due to the very low tissue autofluorescence, high tissue penetration, and good image sensitively and noninvasively.

Successful cancer NIR fluorescence relies on the development of NIR probes with good stability, high fluorescent intense and suitable chemical 1 functionalities for targeting purpose. Porphyrins, with an emission maximum in the NIR region, have been well studied as photosensitizer for photodynamic therapy, because porphyrin is preferentially bound to telomere sequence, which includes more in chromosome of cancer cells than normal cell. Thus, base on the ability to accumulate many kinds of cancer cells, porphyrins are widely used in clinical to the treatment of tumors. Interestingly, porphyrin can form complex 67 67 68 with gallium ( Ga) or Ga, which has interesting physical properties and widely be used as nuclide for radiopharmaceutical research. A novel

Preparation of Fluorescent Organometallic Porphyrin Complex Nanogels

approach to prepare well-defined poly(ethylene glycol) (PEG) fluorescent nanogels, with welldefined molecular structure and desired functionalities via reverse (mini)emulsion CuAAC (REM-CuAAC). This method allows the preparation of nanogels with size in the range of 30 and 120 nm. The fluorescence within the wavelength range of 700-800 nm, the functionality for cell affinity and the biocompatibility of nanogels make them applicable as an ideal NIR probe.

References [1] Guo-Dong Fu, Hua Jiang,Fang Yao,Li-Qun Xu, Jun Ling,En-Tang Kang, Macromolecular Rapid Communications, 2012, 33(18), 1523-1527.

[2] SL. Luo, E. Zhang, Y. Su, T. Cheng, C. Shi. Biomaterials, 2011, 32, 7127-7138 [3] SA, Hilderbrand, R. Weissleder, Curr. Opin.

Chem. Biol. 2010, 14(1), 71-79

Figures

nanoPT2015 Porto (Portugal)

| 49

André S. Gaspar1,4, F.E. Wagner2, V.S. Amaral3, Benilde F.O. Costa1, Luísa Durães4 1 CEMDRX, Physics Department, University of Coimbra, Coimbra, Portugal 2 Physics Department, Technical University of Munich, Garching, Germany 3 Physics Department and CICECO, University of Aveiro, Campus de Santiago, Aveiro, Portugal 4 CIEPQPF, Chemical Engineering Department, University of Coimbra, Polo II, Coimbra, Portugal

Development of a biodegradable magnetic nanoprobe using SPIONs and Amazonian essential oils

andresilvagaspar@gmail.com

Currently, the demand for higher quality magnetic nanoparticles for use as a magnetic nanoprobe to assist in medical imaging techniques and cancer therapy by hyperthermia has been high [1].

Moreover, recent results regarding the phytochemistry benefits that some Amazonian essential oils possess have sparkled great interest in developing methods to use these oils in various medical treatments [2].

The main objective of this work is to develop a biodegradable magnetic nanoprobe which allies the superparamagnetism versatility of iron oxide nanoparticles with the benefits associated with Copaiba and Andiroba’s oils.

In order to improve the capabilities of this biodegradable magnetic nanoprobe, the synthesis method that originates the superparamagnetic iron oxide nanoparticles (SPIONs) [3] [4] was studied and certain paths were tested in order to improve that reaction product. Also, the cytotoxicity of the SPIONs was studied as well as the ability and effects of incorporating the SPIONs in Amazonian essential oils.

Particle size obtained for SPIONs was around 6 nm (figure 1). Mössbauer and XRD analysis indicate maghemite as their main iron oxide phase (figure 2). Also, small traces of magnetite proved to be present in some samples. VSM results showed a magnetization saturation of 57 emu/g, at 7 K, and 42 emu/g, at 300 K (figure 3). After incorporating the SPIONs in Copaiba and Andiroba essential oils these values dropped which indicates that a blocking effect occurs when the Amazonian oils are incorporated with SPIONS.

All the obtained results from the characterization data performed on the various samples seem promising towards having a biodegradable magnetic nanoprobe of SPIONs incorporated in Amazonian essential oils (figure 4).

Keywords: SPIONs; Amazonian essential oils; Copaiba; Andiroba; biodegradable magnetic nanoprobe; Mössbauer spectroscopy; XRD; VSM. References [1] Lodhia, J., Mandarano, G., Ferris, N.J., Eu, P. & Cowell, S.F., Development and use of iron oxide nanoparticles (Part 1): Synthesis of iron oxide nanoparticles for MRI. Biomedical imaging and intervention journal, 2010. 6(2): p. e12 [2] Pieri, F. A., MUSSI, M., & Moreira, M. A. S. (2009). Óleo de copaiba (Copaifera sp.): histórico, extração, aplicações industriais e propriedades medicinais. Rev. Bras. Plant. Med, 11, 465-472.

[3] Xu, Z., Shen, C., Hou, Y., Gao, H. & Sun, S., Oleylamine as both reducing agent and stabilizer in a facile synthesis of magnetite nanoparticles. Chemistry of Materials, 2009.

21(9): p. 1778-1780.

[4] Sun, S., Zheng, H., Robinson, D.B., Raoux, S., Rice, P.M., Wang, S.X. & Li, G., Monodisperse MFe2O4 (M= Fe, Co, Mn) nanoparticles. Journal of the American Chemical Society, 2004. 126(1): p. 273-279.

50 | n a n o P T 2 0 1 5 P o r t o ( P o r t u g a l )

Figures

Figure 3: Magnetization measured as function of an applied field, at 300 K, to the SPIONs incorporated in Amazonian essential oils.

Figure 1: TEM image and respective size distribution calculation for the SPIONs.

Figure 4: Application of an external magnetic field to SPIONs incorporated in Copaiba (top) and SPIONs incorporated in Andiroba (bottom).

Figure 2: Mรถssbauer spectroscopy and XRD diffractogram of the SPIONs

nanoPT2015 Porto (Portugal)

| 51

Vítor M. Gaspar1, Cristine Gonçalves2, Duarte Melo-Diogo1, Elisabete C. Costa1, João A. Queiroz1, Chantal Pichon2, 1 1 Fani Sousa and Ilídio J. Correia 1 CICS-UBI – Health Sciences Research Center, University of Beira Interior, Covilhã, Portugal 2 Centre de Biophysique Moléculaire, CNRS UPR4301, Inserm and University of Orléans, Orléans, France

Simultaneous Delivery of Drugs and Genes by Multiblock Polymeric Nanomicelles for Synergistic Cancer Therapy

vm.gaspar@fcsaude.ubi.pt

Presently cancer remains one of the most predominant incurable diseases and it is estimated that its worldwide incidence will continue to increase in the future [1]. From a clinical perspective chemotherapy is one of the best established methodologies for cancer treatment, being generally applied either as first line therapy for early stage disease, or palliative care in later phases. However, the administration of antitumoral drugs generally induces systemic cytotoxicity due to their poor selectivity to target cancer cells and tissue partition. Moreover, cancer drug resistance following a multi-stage treatment regime is common and this phenomenon further contributes to the ineffectiveness of chemotherapy. In this context the simultaneous delivery of different anti-tumoral drugs or drug-nucleic acid combinations arises as an exceptionally promising strategy for improving treatment efficacy and overcome cancer drug resistance [2]. Nonetheless, combinatorial therapy is remarkably challenging since nucleic acids are readily degraded in circulation and the simultaneous administration of multiple drugs provokes intolerable cytotoxicity.

The use of polymeric micelles is a valuable option to overcome such problems since these nanosized carriers can increase the bioavailability of bioactive molecules, i.e., drugs and genes, in the tumor site by the enhanced permeability and retention (EPR) effect.

This characteristic contributes for reducing systemic cytotoxicity and improves treatment efficacy. Also, due to micelles unique hydrophobic-hydrophilic character which self-assembles into a core-shell structure, they can be used as a reservoir for encapsulating hydrophobic anti-tumoral drugs. In turn, this encapsulation promotes a sustained release during an extended time frame and increases intracellular drug concentration. These two parameters contribute for an enhanced therapeutic effect in comparison to standard chemotherapy. Including drug gene combinations is significantly more challenging as the physicochemical

nature of these distinct bioactive molecules demands a multi-block co-polymer with both hydrophobic and cationic properties so as to encapsulate drugs and complex DNA at the same time [2]. Thus for codelivering drugs and nucleic acids the micelles must be self-assembled from polymeric nanomaterials in which the building blocks ought to be specifically tailored to have these properties.

Herein we provide, a brief focus on the different biocompatible and biodegradable polymers for micelles self-assembly will be provided. The use of biocompatible micelles for co-delivery of antitumoral compounds for cancer therapy will presented. Also, a particular emphasis will be given in the synthesis of innovative tri-block copolymers for gene-drug co-delivery (Figure 1) [3]. The application of this system for the delivery of Doxorubicin and Minicircular DNA (mcDNA) will be presented and the evaluation of its biological performance in vitro and in vivo will be provided.

References [1] Rebecca Siegel, Jiemin Ma, Zhaohui Zou and Ahmedin Jemal, CA: A Cancer Journal for Clinitians, 64(1), (2014), 9-29.

[2] Vítor M. Gaspar, Cristine Gonçalves, Duarte MeloDiogo, Elisabete C. Costa, João A. Queiroz, Chantal Pichon, Fani Sousa and Ilídio Correia, Journal of Controlled Release, 189 (2014), 90-104.

Figures

Figure 1: Schematics of gene-drug (minicircle DNA-Doxorubicin) codelivery concept using multi-block co-polymer micellar carriers.

52 | n a n o P T 2 0 1 5 P o r t o ( P o r t u g a l )

Iaroslav Gnilitskyi1, Ihor Pavlov2, Serim Ilday2, Alberto Rota3, Massimo Messori4, 2 1 Seydi Yavas , Leonardo Orazi and F. Ömer 2,5 Ilday 1 DISMI - Department of Sciences and Methods for Engineering, University of Modena and Reggio Emilia, Italy 2 Department of Physics, Bilkent University, Ankara, Turkey 3 Department of Physics, Computer Science and Mathematics, University of Modena and Reggio Emilia, Modena, Italy 4 Department of Engineering “Enzo Ferrari”, Modena, Italy 5 Department of Eleckrical and Electronics Engineering, Bilkent University, Ankara, Turkey

Strongly anisotropic wetting on highly-uniform self-similar molybdenum nanogrooves

iaroslav.gnilitskyi@unimore.it

Nanostructure formation through surface treatment is mostly performed with well-established techniques including lithography and laser-induced periodic surface structuring (LIPSS). However, these techniques suffer either from the limited flexibility, high-cost, complex equipment, or suffer from the low-speed, problems of material control, and lack of uniformity and repeatability over large areas.

Recently, a technique called Nonlinear Laser Lithography (NLL) was introduced, which allows fabrication of extremely uniform nanostructures, with excellent long-range repeatability and at highspeeds [1]. NLL can be applied to a variety of materials, including non-planar, even flexible surfaces. While NLL generates essentially LIPPS-type of nanostructures, it does so by utilizing nonlinear feedback mechanisms arising from the interaction of femtosecond laser pulses with the target surface, as well as from the laser-initiated chemical reaction.

Key features, such as superior uniformity and ability to process non-flat surfaces are a direct consequence of the self-regulation provided by these feedback mechanisms.

Applications of surface-treated nanostructures have been demonstrated in various fields including electronics, optoelectronics, photovoltaics. Although the outcomes are encouraging, because of the problems of material and process control, they are still not suitable for transfer to industrial applications. It is appears that these problems can be overcome by NLL-induced nanostructures, thanks to their aforementioned superior features, with

potential for substantial impact in these and related fields. However, the technique is new and its potential for these applications needs to be evaluated systematically.

Here, we report on highly uniform, anisotropic, periodic molybdenum nanogrooves fabricated through NLL (Figure 1). We investigate the wettability characteristics of the nanogrooves as a strong candidate to be used for applications where anisotropic wetting of the surfaces is favored, ranging from microfluidics to energy applications to biomedical research such as gas seal conditions, selfcleaning surfaces, directional syringes, microprocessor cooling, high-efficiency hydropower turbines, and nanoscale digital fluidics. Wettability is investigated through contact angle measurements, where sessile drop methodology is used with distilled-deionized water as the test liquid. It is shown that the nanogrooves improved the hydrophilic behavior of the flat molybdenum surface significantly. Moreover, better wetting of the surface along the nanogrooves is observed. It is also shown that we can tune the wettability behavior, where the transition from Wenzel to Cassie regime is observed.

References [1] B. Oktem, I. Pavlov, S. Ilday, H. Kalaycıoglu, A. Rybak, S. Yavas, M. Erdogan, & F. O. Ilday, Nat. Photonics 7 (2013) 897.

nanoPT2015 Porto (Portugal)

| 53

Figures

Figure 1: SEM images of the Molybdenum surface ablated by fs-laser pulses at fluence of 0.7 J/cm2. (a) Nanotextured sample at a 100 mm/s scan speed.(b) Higher magnification image, (c and d) represent higher magnification image of (a), tilted on 45â ° of (a).(e, f) shows the 2D FFT and 1D FFT images of the micrograph (b).

54 | n a n o P T 2 0 1 5 P o r t o ( P o r t u g a l )

J. Patrício1, L. Pereira1,3, L. Rino1,3, M. Ribeiro2, A. Pinto2, A. Marques2, J. Gomes2 1

University of Aveiro, Department of Physics, Campus de Santiago, Aveiro, Portugal 2 CENTI – Centre for Nanotechnology and Smart Materials, Famalicão, Portugal 3 3I3N – Institute for Nanostructures, Nanomodeling and Nanofabrication, Aveiro, Portugal

Optimization of processing and encapsulation conditions of white OLED devices for decorative lighting applications

jgomes@centi.pt

Solid state lighting is one of the most attractive areas either for scientific and research groups in the industrial field [1]. Aside from the new and superLEDs (Light Emitting Diodes) obtained from inorganic semiconductors a novel area of research has been growing towards a very useful technological solution for distinct and revolutionary applications: the OLEDs. These devices offer several advantages over conventional light emitters, namely low power consumption (for same bright compared to the conventional sources), high efficiency, large areas of display and the very attractive possibility of flexible devices (impossible for any other light emitting materials) [2].

However, there are still several scientific issues to be improved before these devices are suitable for market launching. The most relevant are lifetime, device architecture (simple as possible in order to be well reproduced), and optimization of the active layers, either with new materials or by improving the injection layers [3].

In this work, we address the optimization of performance of OLED devices for niche lighting applications considering assessment of the luminescent profile of the materials by a complete optical characterization so to efficiency design the device architecture. The focuses are general lighting with white-OLEDs and decorative lighting applications with coloured OLEDs. The optical properties of the materials processed into thin films (as used in device fabrication) will also be analysed, in order to collect data after the materials molecular conformation. Device fabrication and optimization of processing conditions via thermal evaporation is addressed and detail [4].

corresponding brightness assessment was performed in order to obtain the figures of merit and assess the electrical injection properties.

Additionally, the development of manual encapsulation aiming at stable, durable devices suitable for market applications was explored, with the ensuring study on lifetime of the device [5].

References [1] Kalyani, N.T. e Dhoble, S.J., Organic light emitting diodes: Energy saving lighting technology—A review. Renewable Sustainable Energy Rev., 2012. 16: p. 2696-2723.

[2] Park, J.W., Shin, D.C., e Park, S.H., Large-area OLED lightings and their applications. Semicond.

Sci. Technol., 2011. 26.

[3] Pereira, L., 2012: Organic Light-Emitting Diodes: The use of rare-earth and transition metals; Pan Stanford Publishing.

[4] Tsujimura, T., OLED display structure, em OLED displays: fundamentals and applications. 2012, John Wiley & Sons. p. 24-39.

[5] Singh, J., Field emission organic light emitting diode, em Organic light emitting devices. 2012, InTech. p. 24-26.

A complete optoelectronic characterization of each device using DC measurements, electroluminescence, thermal characterization of a matrix of devices and

nanoPT2015 Porto (Portugal)

| 55

V. M. Gouveia, S. Lima, C. Nunes and S. Reis REQUIMTE, LaboratĂłrio de QuĂ­mica Aplicada, Faculdade de FarmĂĄcia, Porto, Portugal virginia.mgouveia@gmail.com

Rheumatoid arthritis is a chronic systemic inflammatory and autoimmune disease mainly characterized by the progressive inflammation of the synovial tissue of the body joints, destruction of cartilage and further bone erosion. Currently available treatment options include non-steroidal anti-inflammatory drugs, glucocorticoids and disease modifying anti-rheumatic drugs, either used as monotherapy or in combination therapy.

However, all of these therapeutic strategies are associated with severe side effects resultant from limited selectivity and widespread biodistribution of drug molecules into non-target tissues. In order to overcome the drawbacks of conventional therapy, the aim of the following dissertation is to design pH-sensitive liposomes as suitable drug delivery nanosystems for the treatment of rheumatoid arthritis. Although these liposomes are stable at physiological pH, they undergo rapid liposomal destabilization under mildly acidic conditions as those presented in endosomes of target cells. Thus, promising to improve the therapeutic efficiency of a commonly used glucocorticoid prednisolone disodium phosphate -, due to liposomes ability to mediate an intracellular, specific and controlled release of the drug molecules, while limiting adverse offtarget unwanted effects. In this sense, designed pH-sensitive liposomes with specific targeting ligands, as the polyethylene glycol-folic acid or the hyaluronic acid, were developed to enhance the selective and efficient delivery of loaded drug into target synovial macrophages and fibroblast.

Furthermore, the in vitro therapeutic performance of the designed pH-sensitive liposomes was evaluated, through the optimization of its lipid composition, physicochemical characteristics, drug release studies mimicking both biological conditions at pH 7.4 and pH 5.0, cellular studies and, as well as, the liposomal stability during storage. The selectivity and stability of the proposed targeted pH-sensitive liposomes increases the bioavailability of the drug molecules

pH sensitive liposomes loading prednisolone for the treatment of rheumatoid arthritis

at the site of inflammation, once the liposomes specifically internalize into the target cells where they trigger the release of drug and thereby enhance the therapeutic effect, reducing the number of dosages and minimizing the well-known deleterious side effects of prednisolone.

Acknowledgements We thank the financial support through the project PP-IJUP2011-279.

56 | n a n o P T 2 0 1 5 P o r t o ( P o r t u g a l )

Use of Nano-Technology and Nanomaterial in the Development of Nanocomposite Cementitious Materials

Muhammad Ilyas Sheikh, Mizi Fan and Zhaohui Huang School of Engineering and Design, Brunel University, Uxbridge, Middlesex, United Kingdom muhammad.ilyas@brunel.ac.uk

Review for Future Research Openings

The main binder of concrete, Portland cement, represents almost 80% of the total CO2 emissions of concrete. This environmental impact can be reduced by limiting its production and developing alternative cementitious composites. Strength of cementitious material is also an essential requirement and cannot be trade-off by these alternative means.

Development in nanotechnology has led researchers to investigate the complex structure of cement based materials at nano level to address both strength and environmental concerns. In this review paper nanotechnology pathways, recently been paved in the field of nano-composites for cementitious materials, are presented to understand how nanoscience, nano-engineering and nano-indendation is making a great impact in the development of cementitious nanocomposite. Also generally used nanomaterial in the foregoing research to enhance strength, durability and other multifunctional properties of cementitious materials are highlighted. Among hundreds of nanomaterial available, only few of them are attracted by the researchers due to their great influence on properties the cementitious materials. Carbon nanomaterial such as carbon nanotubes (CNTs) and carbon nanofibers (CNFs) generally used in the cementitious materials for enhancing the compressive and flexural strength while nanoparticles of metal oxides such as TiO2, SiO2, Al2O3, Fe2O3 are reported to improve the durability and multifunctional properties such as selfcleaning and self-sensing ability. Moreover, studies on nano-clays, bio-nanomaterial and waste material supplemented with nanomaterial properties are also presented to bridge the gap between previous and future research for the development of environmental friendly high strength cementitious nanocomposite with multifunctional properties.

References [1] Jayapalan, A.R., Lee, B.Y. and Kurtis, K.E. (2013) "Can nanotechnology be ‘green’?

Comparing efficacy of nano and microparticles in cementitious materials", Cement and Concrete Composites, vol. 36, no. 0, pp. 16-24.

[2] Sanchez, F. and Sobolev, K. (2010) "Nanotechnology in concrete – A review", Construction and Building Materials, vol. 24, no. 11, pp. 2060-2071.

[3] Pacheco-Torgal F, Miraldo S, Ding Y, Labrincha J. Targeting HPC with the help of nanoparticles. An overview. Constr Build Mater 2013;38:356–70.

[4] Davalos Jf. Advanace materials for civil infrastructure rehabilitation and protection.

New York: Seminar at The Citty College of New York;2012.

[5] Makar, J. M., and Beaudoin, J. J. (2003).“Carbon nanotubes and their application in the construction industry.”

Proc., 1st Int. Symp. On Nanotechnology in Construction, Paisley, Scotland, UK. ⁞ [90] Shiho Kawashima, Pengkun Hou, David J. Corr, Surendra P. Shah, Modification of cementbased materials with nanoparticles, Cement and Concrete Composites, Volume 36, February 2013, Pages 8-15, ISSN 0958-9465, 10.1016/j.cemconcomp.2012.06.012.

[91] Alireza Naji Givia*, Suraya Abdul Rashidb, Farah Nora A. Azizc and Mohamad Amran Influence of 15 and 80 nano-SiO2 particles addition on mechanical and physical properties of ternary blended concrete incorporating rice husk ash, Journal of Experimental Nanoscience, 2013 Vol. 8, No. 1, 1–18, [92] Hamed Younesi Kordkheili, Salim Hiziroglu, Mohammad Farsi, Some of the physical and mechanical properties of cement composites

nanoPT2015 Porto (Portugal)

| 57

manufactured from carbon nanotubes and bagasse fiber, Materials & Design, Volume 33, January 2012, Pages 395-398, ISSN 0261-3069, 10.1016/j.matdes.2011.04.027.

[93] M. Aly, M.S.J. Hashmi, A.G. Olabi, M. Messeiry, A.I. Hussain, Effect of nano clay particles on mechanical, thermal and physical behaviours of waste-glass cement mortars, Materials Science and Engineering: A, Volume 528, Issue 27, 15 October 2011, Pages 7991-7998, ISSN 0921-5093, 10.1016/j.msea.2011.07.058.

F i g u r e s (Total 10)

CNT Nanocomposite Engineered Concrete

Figure 1: Particle size and specific surface area related to concrete materials [03] (Adopted and modified from the article of Sanchez and Sobolev. Constr Build Mat 24, 2060â&#x20AC;&#x201C;2071).

100 Compressive Strength (Mpa)

50

Flexural Strength (Mpa)

0 S1

S2

S3

Figure 2: Graphical representation of data showing the enhancement of compressive strength and flexural strength using carbon fibres and carbon nanotubes; Extracted from data [42]

58 | n a n o P T 2 0 1 5 P o r t o ( P o r t u g a l )

Yury V. Kolen’ko1, Xiao-Qing Bao1 and Pedro Alpuim1,2

p-Type Cu2O colloids optimized for photoelectrochemistry and electronics

1

INL, Avenida Mestre José Veiga, Braga, Portugal Department of Physics, Universidade do Minho, Braga, Portugal 2

yury.kolenko@inl.int

Owing to appropriate direct band energy of ca.

2.1 eV, high absorption coefficient and high hole mobility, the cuprite Cu2O now stands as a competitive candidate as a photocatalyst for solarassisted photoelectrochemical (PEC) H2 evolution from water. Cu2O is also a promising material for ptype metal-oxide semiconducting inks for solutionbased printing of thin film transistors (TFTs), key components for microelectronics. Many examples of the synthesis of Cu2O micro- and nanocolloids, which allow control over the particle size and shape, are known. A major synthetic challenge, however, is up-scaling the preparation of Cu2O.

the range 25 to 95 ºC, decreases from 0.44 eV to 0.25 eV, respectively.

References [1] A. Paracchino, V. Laporte, K. Sivula, M. Gratzel, E. Thimsen. Nat. Mater., 10 (2011) 456.

Figures

We use an automated synthesis system as a basis for the controlled large-scale surfactant-assisted synthesis of photoactive Cu2O submicroparticles (Figure 1). Structure, morphological peculiarities, as well as enhanced solar H2 evolution performance will be discussed. In particular, as a photocathode for PEC H2 evolution, bare Cu2O submicrocubes have a high onset potential of ca. 0.9 V versus the RHE at pH 1, which is significantly higher than the difference (∼0.54 V) between the Fermi-level + (0.48 V vs. SHE) of Cu2O and the H /H2 redox potential (0.06 V vs. SHE). This indicates a fraction of the photocurrent is induced by the reduction of Cu2O to Cu (0) according to the eq 1 [1]: −

+

Cu2O + 2e +2H → Cu + H2O (1) In addition, nearly monodisperse Cu2O nanocolloids were prepared in high yields through thermal decomposition protocol (Figure 2). Cu2O thin films were further fabricated by spin-coating of the nanocolloids on a 200-nm SiO2@Si wafer.

Room temperature dark conductivity, σd, of the films, measured between parallel coplanar contacts, is thermally activated (Figure 3). σd is in -5 -1 -1 -3 -1 -1 the range 2.1 × 10 Ω cm - 1.2 × 10 Ω cm , while the activation energy of σd, Ea, extracted from temperature-dependent σd measurements in

nanoPT2015 Porto (Portugal)

| 59

Igor Kuzmenko, Tetyana Kuzmenko, Yshai Avishai Ben Gurion University of the Negev, P.O.B. 653, Beer Sheva, Israel

Two-Channel Kondo Effect in Carbon Nanotube Quantum Dot

igorkuz@post.bgu.ac.il

We consider Kondo tunneling through a junction as shown in Fig. 1(a): It is composed of two semiinfinite carbon nanotubes (CNT) that serve as left and right leads (CNTL and CNTR, respectively) attached on both sides of a short CNT quantum dot with an atom A having an s-wave valence electron of spin SA=1/2 implanted on its axis (CNTQDA). The two wave numbers (valleys) K and K’ (located on the two corners of the hexagonal Brillouin zone of the CNT) serve as two symmetry protected flavor quantum numbers ξ=K, K’. The CNTQDA is gated such that its (neutral) ground state consists of the caged atom with spin ±1/2 while its lowest excited (charged) states are singlet and triplet states, see Fig. 1(b). The energies of the singlet and triplet states satisfy inequality εS>εT. The Anderson model hybridizes lead and dot electrons with the same flavor and spin projection, and the Schrieffer-Wolf transformation, while mixing spin projections does not mix flavors, thereby realizing a two-channel Kondo physics.

Employing the poor man's scaling technique to the Kondo Hamiltonian, it is shown that when the ultraviolet cut off energy εT-εF exceeds the Fermi energy εF (measured from the bottom of the conduction band), there are two different regimes of renormalization depending either the effective bandwidth D is above or below its critical value D1= εF, as shown in Fig. 2.

The RG flow pattern of the effective couplings k and j (corresponding to spin-independent potential scattering and spin-flipping exchange interaction) on the effective bandwidth D and the Fermi energy εF is shown in Fig. 3 for the energy of the triplet state εT=18 meV. The flow of k(D) as a function of D is shown in Fig. 3(a) and that of j(D) is shown in Fig. 3(b) for different values of εF. The behavior of the curves (1), (2) and (3) [εF≤1.7 meV] reveals a remarkable scenario of different RG domains: Within the interval D0>D>D1, the effective coupling

j(D) increases above j* (where j*=1/2 is the twochannel fixed point value for j), and then within the interval D<D1, j(D) decreases approaching j*.

This behavior is unexpected, since in the standard two-channel Kondo model, the exchange coupling changes monotonically with D approaching j* for D→0. The non-monotonic behavior is caused by the crossover from the single-channel RG regime for D>D1 to the two-channel RG regime for D<D1.

The Kondo temperature TK is shown in Fig. 4(a) as a function of εT and εF. It is seen that TK changes in between 0.5 K and 5 K for reasonable parameter values.

The conductance G as function of the temperature T is shown in Fig. 4(b) for εT=18 meV and different values of εF. Note the non-monotonic behavior of the conductance for εF≤1.7 meV [curves (1)-(3)].

This exotic behavior is caused by the nonmonotony of j(T) [see Fig. 3(b)]. In the standard 2CKE, G(T) is monotonic, depending on the bare value j0 of j. If j0<j*, (j0>j*), the conductance increases (decreases) monotonically with reducing T. Non-monotony of G(T) exposed here is the result of the crossover between different RG scaling regimes. One of the paradigms of the twochannel Kondo effect is that the physics related to over-screening is exposed only in the strong coupling regime, where T<TK. In this work we have demonstrated that the some physical phenomena related to over-screening can be exposed also in the weak coupling regime, where T>>TK.

References [1] P. Nozières and A. Blandin, J. Physique, 41 (1980) 193.

[2] I. Kuzmenko, T. Kuzmenko and Y. Avishai, submitted to Phys. Rev. B; arXiv:1408.4935.

60 | n a n o P T 2 0 1 5 P o r t o ( P o r t u g a l )

Figures Figure 1: CNTL-CNTQDA-CNTR junction. (a) Schematic geometry of the junction including semi-infinite left and right leads, separated from a quantum dot of length 2h (that hosts a spin 1/2 atom A) by two barriers of width a. (b) Low energy levels of the quantum dot with (from below) the caged atom, followed by triplet and singlet atom-electron states.

Figure 2: Two different intervals of the effective bandwidth D, where different RG regimes are expected.

Figure 3: (a) k and (b) j as functions of D for εT=18 meV and different values εF. Here εS-εT=120 meV and curves (1)-(6) correspond to εF=1.5, 1.6, 1.7, 1.9, 2.1 and 2.3 meV, respectively.

Figure 4: (a) TK as a function of εT and different values of εF. (b) G as function of T for εT=18 meV and different values of εF. For both panels, curves (1)-(6) correspond to εF =1.5, 1.6, 1.7, 1.9, 2.1 and 2.3 meV, respectively. In panel (b), the dots from right to left correspond to D0, D1 and TK, separating the RG regimes from one another.

nanoPT2015 Porto (Portugal)

| 61

Seunghwan Lee and Nikolaos Nikogeorgos Department of Mechanical Engineering, Technical University of Denmark, Lyngby, Denmark

Mucoadhesion to Improve Slipperiness of Mucin Layers

seele@mek.dtu.dk

Mucus gels are viscous slimes that are found from the surfaces of various internal organs, such as cervical, gastrointestinal, oculi, and reproductive tracts. A primary role of mucus gels in biological systems is known to be the protection against pathogens and mechanical insult as well as the lubrication of biological tissues. Mucins, the major macromolecular constituent of the mucus gels, not only serve as a building block of mucus gels, but also display unique slipperiness at the interface between engineering materials by forming lubricating films.

Mucins and mucus gels have received particular interest in the areas of drug delivery [1-4] and biolubrication [5-9]. In the former case, the major interest lies in the mucoadhesive interaction between mucin/mucus and polymers that may be used as drug carriers so as to achieve better control in the delivery and release of drug molecules across the mucus gel on gastrointestinal organs. On the contrary, the latter case is primarily interested in understanding unique slipperiness of mucin/mucus layer at the interfaces of between biological tissues, biological tissue-biomaterials, or between engineering materials. As such, mucoadhesion and slipperiness of mucin and mucus layers appear to be two contradicting characteristics of mucins.

In this study, we demonstrate that mucoadhesion can be rather exploited to enhance the slippery nature of mucins layers. Firstly, the interaction between porcine gastric mucin (PGM) and chitosan were studied at low pH (about 3), where PGM and chitosan are negatively and positively charged, respectively. By varying the ratio of PGM to chitosan, a synergetic lubricating effect between PGM and chitosan based on their mucoadhesive interaction is observed at a hydrophobic interface comprised of self-mated polydimethylsiloxane (PDMS) surfaces. With increasing ratio of chitosan in PGM/chitosan mixture, the interaction of PGM with chitosan led to surface recharge (from negative to positive) and size shrinkage of the aggregates. This resulted in higher mass adsorption on the PDMS

surface with increasing weight ratio of [chitosan]/[PGM + chitosan] up to 0.50. While neither PGM nor chitosan exhibited slippery characteristics, coefficient of friction being close to 1, their mixture improved considerably the lubricating efficiency (coefficient of friction 0.011 at optimum mixing ratio) and wear resistance of the adsorbed layers (See Figure 1 below). A primary driving force of this synergy can be ascribed to the reduction of charges of PGM by the formation of aggregates with oppositely charged chitosan, and consequent suppression of the electrostatic repulsion between PGM on nonpolar PDMS surface, which tends to weaken the stability of the lubricating layer. Similarly, PGM, as well as bovine submaxillary mucin (BSM), showed improved lubricity by forming aggregates with polycations, such as poly(L-lysine) (PLL) or poly(allyl amine) (PAAm) at neutral pH (PBS).

Interestingly, the interaction of PGM with poly(acrylic acid) (PAA) also provided a similar synergic lubricating efficacy at neutral pH (7.4); while neither PGM nor PAA showed any effective lubrication of the sliding contacts of PDMS-PDMS, the mixture of them effectively reduced the coefficient of friction by more than an order of magnitude. This is fairly surprising because, as with PGM, PAA is also negatively charged at this pH, and thus electrostatic repulsion between them is expected. The overall charge of the aggregates, as estimated by zeta potential measurements, also remained negative, in the entire range of aggregates. This observation suggests that the synergetic improvement of lubricating properties of mucins from the interaction with mucoadhesive polymers cannot be ascribed to the reduced charges of mucin-polymer aggregates alone. Instead, it can be concluded that the mucoadhesive interaction between PGM and PAA as achieved via nonelectrostatic interactions, such as hydrogen bonding or hydrophobic interaction, is strong enough to overcome electrostatic repulsion and form the

62 | n a n o P T 2 0 1 5 P o r t o ( P o r t u g a l )

aggregates to assist the formation of network structure between mucins and polymer.

Mucoadhesive polymers act as a physical crosslinker, and the cohesion within the lubricating layer is increased, and finally, chain interpenetration/bridging across the sliding interface bearing polymer layers can be minimized.

Nanoscale sliding contacts of the PGM-chitosan aggregate layers, as studied by atomic force microscopy, also showed lower friction forces in comparison to the reference buffer, primarily due to lower adhesion forces. However, the nanoscale tribological properties of the samples are in clear contrast to their macroscale properties. Firstly, both PGM and chitosan exhibit the lowest friction forces, whereas all the mixtures show higher frictional properties with the 0.50 [chitosan]/[biopolymer] weight ratio displaying the highest friction. Secondly, their frictional differences are much less pronounced at the scale studied by FFM. Integrated probes have a very low radius (~ 30 nm), and thus can penetrate the biopolymer layer under loading conditions. Hence, the friction experienced by the tip is due to its interaction with the substrate, and also due to the resistance applied to it by the adsorbed layer as it plows through it. At the nanoscale the tip and the PDMS are in mechanical contact due to the loading force, and, consequently, the tip has to plow through the adsorbed layer. A higher mass density, such as the film obtained from the [chitosan]/[PGM] at the ratio of 0.33 or 0.50 w/w, means higher number of chains and bonds encountered by the tip per unit length of sliding.

Therefore, higher energy is dissipated per unit

length of sliding by the tip in breaking/disrupting these bonds (chitosan-PGM electrostatic bridges, PGM-PDMS hydrophobic bonds, chain entanglements) as it plows its way through the layer. Moreover, a higher degree of entanglement within the layer may result in a stiffer layer which could also explain a higher force needed by the tip to slide through it. The films formed from neat PGM or chitosan reveal the smallest friction forces, due to the lack of crosslinked bridges between the molecules on the same surface.

References [1] N. A. Peppas and J. J. Sahlin, Biomaterials, 17 (1996) 1553-1561.

[2] N. A. Peppas and Y. Huang, Adv. Drug Delivery Rev., 56 (2004) 1675-1687.

[3] J. D. Smart, Adv. Drug Delivery Rev., 57 (2005) 1556-1568.

[4] V. V. Khutoryanskiy, Macromol. Biosci., 11 (2011) 748-764.

[5] G. Cassin, E. Heinricha and H. A. Spikes, Tribol.

Lett., 11 (2001) 95-102.

[6] E. Perez and J. E. Proust, J. Colloid Interface Sci., 118 (1987) 182-191.

[7] M. Malmsten, E. Blomberg, P. Claesson, I. Carlstedt and I. Ljusegren, J. Colloid Interface Sci., 151 (1992), 579-590.

[8] N. M. Harvey, G. E. Yakubov, J. R. Stokes and J. Klein, Biomacromolecules 12 (2011) 1041â&#x20AC;&#x201C;1050.

[9] S. Lee, M. M. ller, K. Rezwan and N. D. Spencer, Langmuir, 21 (2005) 8344-8353.

Figures

Figure 1: Coefficient of friction obtained from the sliding contacts between PDMS surfaces as lubricated by the aqueous solutions of PGM (0.1 mg/mL), chitosan (0.1 mg/mL), and their mixtures (1:1, 0.1 mg/mL in total biopolymer concentration) (Left panel)

nanoPT2015 Porto (Portugal)

| 63

Sofia A. Costa Lima and Salette Reis REQUIMTE, Departamento de Ciências Químicas, Faculdade de Farmácia, Universidade do Porto, Portugal slima@ff.up.pt

Interest in developing multifunctional nanoparticles for a therapeutic application has recently gain particular focus in several diseases (cancer, infections, and inflammatory disorders) because of their unique theranostic properties. Theranostic combines therapeutics and diagnosis in a single multifunctional platform. These nano-carriers would preferentially target at the disease site, diagnose morphological changes of tissue of interest and provide effective therapy [1]. Multifunctional nanoparticles, containing stimuli-sensitive components, able to respond to internal and/or external triggers have appeared [2]. An example of such external trigger application is the photothermal driven drug delivery, through a nano-delivery system that, following intravenous administration, releases its payload at the site of interest upon application of a local near-infrared (NIR) light. NIR resonant nanomaterials, such as gold nanoshells [3] and gold nanoparticles strongly absorb NIR light producing local cytotoxic heat upon irradiation.

Chemo-photothermal therapy is a successful theranostic approach with the combination of chemotherapy and photothermal therapy that has recently emerged as a promising anticancer treatment [4]. Here, we intend to further explore the application of theranostic nanoparticles in the treatment of rheumatoid arthritis (RA). Permeability of rheumatoid synovium highly resembles solid tumours (e.g. leaky nature of their vasculature) [5] and the small synovial joints are within the penetration depth of NIR light, thus, multifunctional nanoparticles can be a promising tool for RA therapy.

In the present work, a novel stealth polymeric nanospheres platform able to carry antiinflammatory drugs and an imaging agent was develop. The strategy to design a chemophotothermal multifunctional platform was based on stealth polymeric nanospheres of pegylatedpoly(DL-lactic-co-glycolic acid) (PEG-PLGA)

Temperature-responsive polymeric nanospheres containing methotrexate and gold nanoparticles: a multidrug system for theranostics in rheumatoid arthritis containing methotrexate (MTX) and gold nanoparticles (Au NPs) for the treatment of RA as (i) MTX is effective in the management of RA when administered systematically or locally through intraarticular injections [6] and (ii) Au NPs have been used in RA therapy per se [7], but can also be used as contrast agent for photoacoustic imaging [8] and as an external trigger for thermo-responsive controlled drug delivery. Through emulsion-diffusion evaporation technique MTX was incorporated in the pegylated polymeric nanospheres in the presence or not of Au NPs. In vitro dug release assays revealed pH and temperature gold nanoparticlesdependence. Blank nanospheres exhibited negligible in vitro cytotoxicity, while MTX-loaded nanospheres hampered monocytes and macrophages viability at a higher level than free MTX. Moreover, confocal fluorescent microscopy and flow cytometry revealed effective nanospheres internalization in human THP1 monocytes and macrophages. The cellular uptake was energy dependent and mediated by caveolae and clathrin-endocytosis mechanism. The MTX-loaded multifunctional nanospheres antiinflammatory activity was evaluated using an in vitro model of RA involving monocytes and macrophages.

Any change in the secretion of cytokines (IL-1β, IL-6 and TNF-α) in relation to the untreated stimulated cells indicate that the MTX and Au NPs incorporated on the multifunctional nanospheres retained their bioactivity and were able to reduce the inflammatory response in vitro. Results revealed that the MTX-loaded multifunctional nanospheres containing gold lead to a significant suppression of the pro-inflammatory cytokines produced by monocytes and macrophages, suggesting a favorable anti-inflammatory activity. These results confirm that the multifunctional nanospheres represent a promising theranostic platform for RA diagnosis and intracellular treatment, by combining methotrexate and gold nanoparticles for a highly effective targeted chemo-photothermal therapy.

64 | n a n o P T 2 0 1 5 P o r t o ( P o r t u g a l )

References [1] Muthu MS, Mei L, Feng SS, Nanomedicine (Lond), 9 (2014) 1277.

[2] Li M-H, Keller P, Soft Matter, 5 (2009) 927.

[3] Lee SM, Park H, Choi JW, Park YN, Yun CO, Yoo K-H, Angew Chem, 50 (2011) 7581.

[4] Lee SM, Kim HJ, Kim SY, Kwon MK, Kim S, Cho A, et al., Biomaterials, 35 ( 2014) 2272.

[5] Levick JR, Arthritis Rheum, 24 (1981) 1550.

[6] Ramiro S, Gaujoux-Viala C, Nam JL, Smolen JS, Buch M, Gossec L, et al., Ann Rheum Dis, 73 (2014) 529.

[7] Tsai CY, Shiau AL, Chen SY, Chen YH, Cheng PC, Chang MY, et al., Arthritis Rheum, 56, (2007) 544.

[8] Yang S, Ye F, Xing D, Opt Express, 20 (2012) 10370.

Figures

Figure 1: Schematic illustration of the synthesis of multifunctional nanospheres through a modified solvent evaporation single emulsion method for RA chemo-photothermal therapy.

nanoPT2015 Porto (Portugal)

| 65

Lifeng Liu International Iberian Nanotechnology Laboratory (INL), Av. Mestre Jose Veiga, 4715-330 Braga, Portugal lifeng.liu@inl.int

Hydrogen evolution reaction (HER) is one of the most important half reactions in electrolyzers and photoelectrochemical cells. In order for these electrochemical devices to be widely employed, developing highly efficient, durable and low-cost HER electrocatalysts is critically needed.

Molybdenum disulfide (MoS2) has recently emerged as a promising alternative catalyst to precious platinum to catalyze HER [1]. Despite remarkable progress made recently, the intrinsic poor electrical conductivity and unfavorably exposed active sites have hampered further improvement of the HER activity of MoS2. Herein, we report that amorphous MoOxSy electrodeposited on a high surface area crystalline TiO2 nanotube (TNT) array support can exhibit extraordinarily high electrocatalytic activity toward HER (see Figure 1), with unprecedentedly -2 large current density of 115.8 mA cm at an overpotential as low as 150 mV and an extremely low overpotential of 29.1 mV to reach a current -2 density of 20 mA cm [2]. Furthermore, after iR correction, a cathodic current density as high as -2 171.8 mA cm can be achieved at an overpotential of 150 mV, the largest one reported so far to the best of our knowledge. Besides, the TNT supported MoOxSy catalyst (TNT@MoOxSy) also shows excellent durability in acidic solutions without obvious performance degradation after 3000 cyclic voltammetric scans (see Figure 2). The remarkable HER performance of the TNT@ MoOxSy can be attributed, on the one hand, to the high specific surface area and excellent electron transport property of the TNT/Ti array support; and on the other hand, possibly to the enhanced electrical conductivity of the catalyst itself because of the incorporation of oxygen.

Extraordinarily Efficient Electrocatalytic Hydrogen Evolution Achieved by Amorphous MoOxSy Catalysts Electrodeposited on Crystalline TiO2 Nanotube Arrays Figures

Figure 1: (a) HAADF image of a single TiO2@MoOxSy nanotube.

Elemental maps of (b) Ti, (c) O, (d) Mo and (e) S.

References [1] Vrubel, H.; Merki, D.; Hu, X.L. Energy Environ.

Sci. 5 (2012) 6136-6144.

[2] L.F. Liu, under preparation

Figure 2: The stability test of the TiO2@MoOxSy electrodes.

66 | n a n o P T 2 0 1 5 P o r t o ( P o r t u g a l )

Zanna Martinsone, Anita Seile, Inese Martinsone, Pavels Sudmalis, Ilona Pavlovska, Ivars Vanadzins, Jelena Reste, Tija Zvagule, Natalja Kurjane Rigas Stradins University, Institute of Occupational Safety and Environmental Health, Riga, Latvia

Instrumentation for qualifying and quantifying nanoparticlesâ&#x20AC;&#x2122; exposure into occupational environment

Zanna.Martinsone@rsu.lv

The work characteristics, technology and tools are constantly changing, especially in countries such as Latvia, where since the early nineties the occupational environment is developing.

Occupational environment air quality is an important public health factor what influence personsâ&#x20AC;&#x2122; health and well-being. Occupational air quality is characterized by physical (microclimate: air temperature, relative humidity, noise, lighting, etc.), chemical (dust, inorganic compounds: formaldehyde, carbon dioxide, organic compounds, etc.) and biological (dust mites, molds, etc.) pollutants. Much attention in the world is given to a very fine dust particles (PM10, PM2.5 and PM0.1, where the PM - Particular matter - particulates with a diameter of 10 mm, 2.5 mm and 0.1 mm or 100 nm - nanoparticles) in ambient and during last 10 years also in the occupational environment. Dust particles, especially nanoparticles, are identified as one of the emerging risk factors of occupational environment. Because the particles are finer and there many of them in the air their active surface area is greater. It is important to note the importance of the chemical composition of dust particles [1]. However, dust particles are not enough investigated, including adverse effects of nanoparticles in occupational environment and the health of workers, quality of life, work capacity and productivity.

There are little research in the world on nanoparticle exposure in the occupational environment and the information is controversial about the nanoparticles health effects related with nanoparticles chemical composition, structure, and induced effects. Open is the question of the toxicity of nanoparticles and correlation with particle properties. The assessment of harmful effects caused by the nanoparticles are used markers of inflammation and allergies, but there is lack of comprehensive information about

nanoparticle effects on different biological processes (oxidative stress, cancer aetiology, DNA damage) [2;3;1]. Therefore the studies of nanoparticle toxicity and nanoparticle exposure assessment methods and instrumentation are very topical with development of technology (especially nanotechnology) and the production of materials.

There is limited facifilities use the mobile and informative instrumentation for particle (also nanoparticle) quantifying and qualifying particles into occupational environment. However there are some instruments what were and are tested still into occupational environment of Latvia. According to data from the office environment (pilotproject data, see Figure 1), more useful and informative is "P-Trak ultrafine Particle Counter" Model 8525 (particle size: 20 - 1000 nm) for particle counting at occupational environment; other - "AeroTrak 9000" (nanoparticles size: 10 - 1000 nm; particle surface area are determined in two fractions: TBtraheobronhial (particle size <1000 nm) and Aalveolar (particle size <250 nm)) for particle surface area measurements (see Figure 2). For simultaneous particles size distribution, counting, surface area measurement, mass concentration measurements from experience very informative is ELPI+. Besides doing air measurements by ELPI+, it is possible collect dust samples also for dust gravimetric (sampling aluminium foils as collection substrate), chemical (on polycarbonate foils as collection substrate) and electron microscopy analyses (see Figure 1). Next step of testing this instrumentation will be welding and wood-working processes. All previously counted instrumentation for particles (also nanoparticles) exposure measurements gives possibilities to make air sampling as close as possible to workers breathing zone what is important for correct occupational exposure quantification and qualification. But personal sampling instrumentation for simultaneous nanoparticlesâ&#x20AC;&#x2122; counting, surface

nanoPT2015 Porto (Portugal)

| 67

area, mass, size distribution etc. parameters is still under development process and gives higher precision on workers’ personal exposure calculations.

Figures

Acknowledgements Project “The development of up-to-date diagnostic and research methods for the risks caused by nanoparticles and ergonomic factors at workplaces”, Agreement No. 2013/0050/1DP/1.1.1.2.0/13/APIA/ VIAA/025 References [1] Maynard AD, Kuempel ED, Airborne nanostructured particles and occupational health, Journal of Nanoparticle Research, Issue 7(6) (2005), 587-614 page.

[2] Öberdörster G, Öberdörster E, Öberdörster J., Nanotoxicology: An emerging discipline evolving from studies of ultrafine particles, Environmental Health Perspectives, Issue 113 (7) (2005), 823-839 page.

[3] Cormier SA, Lomnicki S, Backes W and Dellinger B, Origin and Health Impacts of Emissions of Toxic By-Products and Fine Particles from Combustion and Thermal Treatment of Hazardous Wastes and Materials, Environmental Health Perspectives, Issue 114 (6) (2006), 810-817 page.

Figure 1: Laserprinters distributed dust particles (D1, D2, D3) sizes in nanometers (nm).

Figure 2: The alveolar fraction of dust particle surface area concentration in copy shop sampling by "AeroTrak 9000".

68 | n a n o P T 2 0 1 5 P o r t o ( P o r t u g a l )

M. May, H. M. Wang, R. Akid 1. Material Engineering Department, Faculty of Engineering, Sebha University, Sabha - Libya 2. Materials and Engineering Research Institute, Sheffield Hallam University, UK 3. School of Materials, the University of Manchester.

Manchester, U.K

Effects of γ-Al2O3 nanoparticles on the adhesive strength of composite epoxy/sol-gel materials

The use of composite sol-gel/epoxy adhesive based on the combination of organic and inorganic components within the adhesive matrix have been studied. The incorporation of different amounts of γ-Al2O3 nano-particles into the adhesive matrix was evaluated. Mild steel specimens were prepared for lap joints, which were cured in an oven at 200°C for 16 hours. The bond strength of the sol-gel/epoxy matrix was investigated using a universal tensile test machine. Initially there was an increase in shear strength of sol-gel/epoxy adhesive with increase in γ-Al2O3 up to 4.0 wt%. This may be because the nano γ-Al2O3 increased the crosslinkage where many surface hydroxyl group on γ-Al2O3 materials and in silica sol-gel may react during the polymerisation stage as Al-O-Si bond and enhanced the adhesion strength per interaction area within the adhesive matrix. The maximum adhesive strength of composite sol-gel/epoxy adhesive recorded was 23±0.4MPa. However, as the level of these inorganic materials in adhesive matrix increased further, the adhesive shear strength gradually decreased. The reduction in the strength can be attributed to the increase in adhesive viscosity. The behaviour of the adhesive formulation changes from a liquid-like to a more solid-like state, reducing its wetting ability on the substrate surface, and thus decreasing shear strength.

nanoPT2015 Porto (Portugal)

| 69

Arben Merkoçi ICREA & Catalan Institute of Nanoscience and Nanotechnology (ICN2), Bellaterra (Barcelona), Catalonia, Spain

Nanobiosensors And Applications In Diagnostics

arben.merkoci@icn.cat www.nanobiosensors.org www.icn.cat

Nanomaterials (NM) with electrical and optical properties are playing a key role in the design of cutting edge biosensing technologies.

Electrocatalytic, plasmonic and quantic properties of NMs such as gold nanoparticles, quantum dots or graphene while operating in simple plastic or paper matrix in diagnostic and safety/security applications will be shown. The effect of the platform architecture and other chemical and physical parameters upon biosensing and actuation including nano/micromotors pick-up or mixing operations will be discussed. The developed smart nanobiosystems are with interest for integration of diagnostic with therapies (nanotheranostics) or sensing and destruction/removal (sensoremoval) for health and environment industries. Examples related to protein (ex. neurodegenerative disease biomarkers), DNA (pathogen related) or cells (cancer cells) with interest for point of care applications will be shown.

The developed devices and strategies are intended to be of low cost while offering high analytical performance in screening scenarios beside other applications. Special emphasis will be given to labon-a-chip platforms with integrated electrochemical detection with interest for either clinical or environmental monitoring (including sensoremoval).

In addition simple paper-based platforms that operate in lateral flow formats with interest for heavy metals or protein detection will be shown.

Various enhancement technologies ranging from microfluidics architectures changes, in-chip recirculations as well as actuation via nano/micromotors able to either pick-up analytes or improve reaction medium in solid-liquid phase sensing technologies will be discussed.

References [1] C. Parolo, A. Merkoçi, “Paper based nanobiosensors for diagnostics”, Chem. Soc. Rev., 42 (2013), 450—457 [2] A. M. Lopez_Marzo, J. Pons, D. A. Blake, A. Merkoçi, “All-Integrated and Highly Sensitive Paper Based Device with Sample Treatment Platform for Cd2+ Immunodetection in Drinking/Tap Waters”, Anal. Chem., 85 (2013), 3532–3538 [3] E. Morales-Narváez, A. R. Hassan, A. Merkoçi, “'Graphene oxide as a pathogen-revealing agent: sensing with a digital-like response', Angew.Chem.Int.Ed. 52 (2013), 13779 –13783.

[4] E. Morales-Narváez, H. Montón, A. Fomicheva, A. Merkoçi, “Signal Enhancement in Antibody Microarrays Using Quantum Dots Nanocrystals: Application to Potential Alzheimer’s Disease Biomarker Screening”, Analytical Chemistry, 84 (2012), 6821−6827 [5] A. Escosura-Muñiz, A. Merkoçi, “Nanochannels Preparation and Application in Biosensing”, ACS Nano 6 (2012), 7556–7583 [6] E. Morales-Narváez, M. Guix, M. MedinaSánchez, C. C. Mayorga-Martinez, A. Merkoçi, “Micromotor Enhanced Microarray Technology for Protein Detection”, Small 2014, 2542–2548.

[7] E.Morales-Narvez, A.-R. Hassan, A. Merkoçi, Graphene Oxide as a Pathogen-Revealing Agent: Sensing with a Digital-Like Response, Angwandte Chemie, 52, 13779–13783, 2013

70 | n a n o P T 2 0 1 5 P o r t o ( P o r t u g a l )

Farzin Mohseni, M. J. Pereira, N. M. Fortunato, J. S. Amaral, A. C. Lourenço, J. M. Vieira

Magnetic and morphologic properties of Alnico-based rare-earth free permanent magnets

Department of Physics, University of Aveiro, 3810-193, Aveiro, Portugal f.mohseni@ua.pt

Due to recent dramatic increases in the price of rare-earth elements, rare-earth free permanent magnet research is nowadays a very active field [1].

Alnico V alloys, first discovered in the 30’s, are hard ferromagnets, with high working temperatures, albeit with modest coercivity, below 1 kOe [2]. This makes their energy product (~12 MGOe) compare unfavorably with rare-earth based NdFeB magnets (~55 MGOe). Recently, an unusually high coercivity value, up to ~10 kOe, was reported for DC-sputtered Alnico V thin-films on Silicon substrates [3, 4], due to the formation of a novel Body Centered Tetragonal Fe-Co-Si phase, a result of diffusion of Si ions from substrate to thin film. This diffusion mechanism is still unclear, and the chemical composition and saturation magnetization of this novel phase are not yet characterized.

We report on the effects of deposition temperature and post heat treatments on the morphology and magnetic properties of Alnico V thin films prepared

by RF-sputtering. The sputtering target was of commercial Alnico V alloy, and substrates were of 700 µm thick Si(100). Samples of 180 nm thickness were prepared at different deposition temperatures, ranging from room temperature to 560 ̊C. Postdeposition heat treatments in vacuum at 600, 800 and 900 ̊C, followed by quenching in liquid Nitrogen and slow-cooling, were performed.

Atomic Force Microscopy (AFM) shows that both an increase of deposition temperature as well as post heat treatments lead to a considerable increase of roughness, from <0.8 nm to 80 nm, for heat treatments at 600 ̊C, and 50 nm for a deposition temperature of 500 ̊C (Figure 1).

The chemical composition of the thin films was analyzed by Electron Dispersion Spectroscopy (EDS) in a Scanning Electron Microscope (SEM). The composition of films deposited at room temperature, matches that of the target, while for higher substrate temperatures the ratio between

transition metals is altered, and post-deposition heat treatments introduce contaminations to the thin films. Figure 2 shows the cross-section SEM image of the as-made and heat treated films.

Magnetization analysis using a Vibrating Sample Magnetometer (VSM) shows that substrate temperature affects the saturation magnetization, lowering it drastically for high temperatures. In the case of heat treatments this decrease is smoother, but still quite substantial, particularly for quenched samples. Coercivity is unaffected by deposition temperatures in this range, while increasing considerably (from < 20 Oe for as-deposited films up to 480 Oe) in heat-treated samples (Figure 3).

Future studies will focus on film thickness and substrate temperature optimization, and the control of surface roughness under heat-treatments, by adding a capping layer to the films (Ag, Ta), preventing also the observed oxidation of the surface during heat treatment and quenching.

References [1] Narayan Poudyal and J Ping Liu, “Advances in Nanostructured Permanent Magnets Research”, Journal of Physics D: Applied Physics 46 (2013) 043001 (23pp).

[2] K. H. J. Buschow, “New Developments in Hard Magnetic Materials”, Reports on Progress in Physics 54 (1991) 1123-1213.

[3] O. Akdogan, G. C. Hadjipanayis, “Alnico Thin Films with High Coercivities up to 6.9 kOe”, Journal of Physics: Conference Series 200 (2010) 072001.

[4] O. Akdogan, W. Li, G. Hadjipanayis, “High Coercivity pf Alnico Thin Films: Effect of Si Substrate and the Emergence of Novel Magnetic Phase”, Journal of Nanoparticle Research (2012) 14 891.

nanoPT2015 Porto (Portugal)

| 71

Acknowledgements We acknowledge funding from FEDER/COMPETE through FCT, FCOMP-01-0124-FEDER-037271 (PEst-C/CTM/LA0011/2013) and EXPL/CTMNAN/1614/2013 - FCOMP-01-0124-FEDER-041688 Figures

Figure 1: AFM image of a) as-deposited, b) after heat treatment and c) deposited at 560 Ě&#x160;C.

Figure 3: Effects of a) heat treatment followed by slow cooling, b) heat treatment followed by quenching and c) deposition temperature on hysteresis loop

Figure 2: Cross sectional SEM image of a) as-deposited, b) after heat treatment

72 | n a n o P T 2 0 1 5 P o r t o ( P o r t u g a l )

Lars Montelius

Bridging the materials gap through radical Innovations

INL - International Iberian Nanotechnology Laboratory, Braga, Portugal lars.montelius@inl.int www.inl.int

Nanotechnology is a Key Enabling Technology with promises for making solid contributions to the grand challenges of today, such as sufficient sustainable energy supply, access to clean water, care of the elderly population and making cities ready for the globalization.

At INL, the Internatioal Iberian Nanotechnology Laboratory, we are implementing a full ecosystem for nanotechnology innovation and science. I will discuss about our offers and describe the possibilities that exist for collaboration with university and institutions and companies.

Then I will discuss about how nanotechnology could be of importance to bring added value to products and services. I will also review some areas of nanotechnology that recently has been deployed giving rise to radical innovation and business development.

By creating working and living environments with situation-specific forms and levels of sensory stimulation, we can improve the conditions for productivity, learning, health, comfort and wellbeing. Ever more people talk about Smart Lighting, i.e. a lighting that is adaptive (on demand), interactive (by control) and dynamic (color & intensity). The main basis for Smart Lighting is that the LED and ICT of today creates a more or less unlimited flexibility to deliver a dynamic user adapted light - the right light, at the right place, at the right time, for each and everyone.

In the end I will discuss about the need for articulation in science and innovation actions.

In particular, I will address the accelerated development of LEDs and the consequences on lighting. Lighting is increasingly becoming an integral part of the Digital Age. The lighting of the future will be more attractive, individually tailored and integrated into Smart Buildings and Smart Cities.

Even today, you can access the Internet via LED luminaries.

nanoPT2015 Porto (Portugal)

| 73

Artur M. Pinto1,2, Carolina Gonçalves1, Inês C. Gonçalves2, Fernão D. Magalhães1 1 LEPABE, Faculdade de Engenharia, Universidade do Porto, Porto, Portugal 2 INEB, Universidade do Porto, Porto, Portugal

arturp@fe.up.pt

Two types of graphene-nanoplatelets (GNP-M and GNPC) were incorporated in PLA (poly(lactic acid)) by melt blending. Materials were biodegraded during 6 months and characterized by XRD, tensile tests, DMA and biocompatibility assays. For both fillers, low loadings (0.25 wt.%) improved mechanical properties and decreased their decay until 6 months biodegradation.

PLA degradation decreased its toughness (AUC) by 10 fold, while for PLA/GNP-M and C after 6 months degradation, toughness was only reduced by 3.3 and 1.7 fold, respectively. Comparing with PLA, PLA/GNP-M and C composites presented similar (HFF-1) fibroblasts adhesion and proliferation at the surface and did not released toxic products (6 months).

Introduction Graphene is a single layer of sp2 carbon atoms arranged in a honeycomb structure and possesses extraordinary mechanical strength and an extremely high surface area. [1] A commercial available product, with reduced cost comparing with single layer graphene, graphene nanoplatelets (GNPs), are constituted by few stacked graphene layers, possessing oxygen containing functional groups in the edges. GNPs present high aspect ratio, thus forming a percolated network in composites, with large interfacial interaction between platelets and polymer matrix, mainly in the edges, resulting in effective load transfer and increased strength. [2] Moreover, these materials were shown to be non-toxic when incorporated in low percentages into PLA. [3] The potential of GNPs as polymers fillers, has been observed in our previous study, in which improvements in mechanical properties of PLA thin films were obtained at filler loadings bellow 1 wt.%.

Solvent mixing was used for GNPs incorporation, [4] however the use of solvents should be avoided due to the toxicity of residues that may remain in the materials, and for industrial workers [5]. Lahiri et al. improved ultrahigh molecular weight polyethylene mechanical properties producing composites by electrostatic deposition of GNPs 1 wt.%. However, composites were toxic to osteoblasts because filler leaching occurred. [2] Thus, melt blending, which assures complete embedding of GNPs in polymer matrix

Effect of biodegradation on PLA/graphene-nanoplatelets composites mechanical properties and biocompatibility

preventing filler leaching, is studied in this work as a green method for production of PLA/GNPs composites.

Materials and Methods PLA 2003D, was purchased from Natureworks.

Graphene-nanoplatelets, grade C750 (GNP-C) and M-5 (GNP-M) were acquired from XG Sciences. PLA/GNP-M and C 0.25 wt.% composites were prepared by melt blending in a Thermo Haake Polylab (180 °C, 15 min, 25 rpm), and moulded in a hot press (190 ºC, 2 minutes) into thin sheets (0.3-0.5 mm). Samples were immersed in 50 mL PBS in sterile conditions and incubated for 6 months (37 °C, 100 rpm). X-Ray diffraction (XRD) analysis, was performed using a Philips X´Pert diffractometer. Tensile properties of the composites (60x15 mm) were measured (Mecmesin Multitest-1d, Mecmesin BF 1000N) at room temperature and strain rate of 10 mm min-1. Dynamical mechanical analysis (DMA) was performed using a DMA 242 E Artemis (Netzsch) in tension assays (6N, 10 minutes) with 10 minutes recovery. Biocompatibility of materials was evaluated using HFF-1 cells cultured at the surface of PLA, PLA/GNP-M and C 0.25 wt.% films (Ø = 5.5 mm) and in direct contact with materials extracts obtained after 6 months incubation in PBS (50 µL in 150 µL DMEM+, after 24h cell grow). In both assays cells were seeded in 96 well plates (7500 cells per well) and 20 µL resazurin solution added at 24, 48, and 72h and incubated for 3h, fluorescence (λex/em=530/590 nm) read and metabolic activity evaluated (Metabolic activity (%) = Fsample/FPLA x 100). Suitable controls were performed for both biocompatibility assays.

Results and discussion XRD GNP-M and C powders present similar XRD spectra, typical of carbon materials, with an intense peak around 31°, and two broad peaks around 50° and 65°. PLA, before (0M) and after 6 months (6M) biodegradation, presents similar spectra with two broad peaks, the first, around 20°, is more intense than the second, around 35°. PLA/GNP-M 0.25 wt.% 0 and 6M present similar spectra, with PLA and GNP-M peaks being observed, which confirms the filler presence in polymer matrix.

For PLA/GNP-C 0.25 wt.% 0M and 6M spectra are also

74 | n a n o P T 2 0 1 5 P o r t o ( P o r t u g a l )

similar, however GNP-C peak is less intense than GNP-M peak.

Tensile tests Incorporation of GNP-C and M in PLA increased its Young´s modulus by 14 %. Also, tensile strength is increased by 20% with GNP-C incorporation and by 6% with GNP-M. Improvements in toughness of 20% are only observed for GNP-C. After 6 months biodegradation no significant changes are observed in Young´s modulus for all materials tested. Decreases in tensile strength, elongation at break, and toughness are respectively, for PLA of 2.6, 2.5, and 10 fold, for GNP/PLA-M of 1.6, 1.8 and 3.3 fold, and for GNP-C of 1.4, 1.4 and 1.7 fold. Thus, the presence of the fillers prevents decreases of PLA mechanical properties with biodegradation, namely tensile strength, elongation at break and toughness. Also, GNP-C incorporation seems to have a more beneficial effect than GNP-M, especially in toughness.

DMA Figure 1 shows that for PLA, dLf (final, at 6N) after 10 cycles before degradation was of 14.2 µm, being of 13.7 and 13.2 µm for PLA/GNP-M and C 0.25 wt.%, respectively. After 6 months degradation, PLA sample ruptured after 4 cycles (1.A) reaching a dLf of 56.3 µm, PLA/GNP-M and C 0.25 wt.% did not ruptured (1.B,C) and presented a slight increase in dLf, which were of 16.8 and 16.7 µm, respectively.

These results are in agreement with those obtained in tensile tests, with a significant decay in PLA mechanical properties after 6 months biodegradation and small effects observed for PLA/GNP-M and C 0.25 wt.%. Thus, fillers are reinforcing the polymer matrix and retarding decrease of its mechanical properties. Materials degradation was confirmed by GPC-SEC and SEM (results not shown).

Cell adhesion and proliferation assays HFF-1 cell metabolic activity at PLA surface was 75% at 24 and 48h, and 94% at 72h, comparing with cells at tissue culture treated surface of 96 well plates.

PLA/GNP-M and C 0.25 wt.%, metabolic activity never decreased below 90%, for both composites in comparison with PLA. Thus, fillers incorporation has no impact in cell adhesion and proliferation at materials surface.

Degradation products cytotoxicity A control performed with PBS (37 ºC, 100 rpm, 6 months) presented similar cell metabolic activity (24, 48, 72h) to PLA 6M degradation products, which shows that they are not toxic. Figure 2 shows that degradation products of PLA/GNP-M and C 0.25 wt.% 6M are not toxic (24, 48, 72h), comparing with PLA 6M, according to ISO 10993-5:2009(E), which considers toxic a material that decreases cell viability below 70% of negative control for cell viability. Also, cell morphology is normal and similar for all conditions tested (images not shown).

Conclusions GNP-M and GNP-C incorporation in PLA matrix at low loadings (0.25 wt.%) improved mechanical properties and decreased their decay until 6 months biodegradation. These nano-fillers can be used to tune PLA mechanical performance during biodegradation.

PLA/GNP-M and C composites allow similar HFF-1 cell adhesion and proliferation at the surface and do not release toxic products.

References [1] Kim K, Abdala A and Macosko W, Macromolecules, 43 (2010) 6515.

[2] Lahiri D, Rupak D, Cheng Z, Socarraz-Novoa I, Bhat A, Ramaswamy S, Agarwal A, ACS Appl. Mater.

Interfaces, 4 (2012) 2234.

[3] Pinto AM, Moreira S, Gonçalves IC, Gama FM, Mendes AM, Magalhães FD., 2013.

Biocompatibility of poly(lactic acid) with incorporated graphene-based materials, Colloids Surf B Biointerfaces, 104 (2013) 229.

[4] Pinto AM, Cabral J, Tanaka DA, Mendes AM, Magalhães FD, Effect of incorporation of graphene oxide and graphene nanoplatelets on mechanical and gas permeability properties of poly(lactic acid) films, Polymer International, 62 (2013) 33.

[5] Pinto AM, Gonçalves IC, Magalhães FD, Colloids and Surf B Biointerfaces, 111 (2013) 188.

Figures

Figure 1: Multi cycle DMA of PLA and composites before and after 6 months degradation.

Figure 2: Cytotoxicity of PLA/GNP-M and C 0.25 wt.% 6 months degradation products, comparing with PLA in the same conditions.

Assays were performed in triplicate, with 6 replicates for each condition tested. Error bars represent standard deviation. Red line represents cytotoxicity limit of 70%.

nanoPT2015 Porto (Portugal)

| 75

V. Morin, S. Bauerdick, P. Mazarov, L. Bruchhaus, R. Jede Raith GmbH, Dortmund, Germany vincent.morin@raith.de

Ion Column and Source technology employing Gallium and New Ion Species for Advanced FIB Nanofabrication

An increasing number of applications use focused ion beam (FIB) systems for nanofabrication and rapid prototyping tasks. FIB nanofabrication is a good partner to other lithography techniques providing complementary strengths like direct, resistless, and three-dimensional patterning.

Although a FIB process can in many cases be slower than a resist-accelerated process, the relative simplification of the overall nanofabrication approach, especially for the direct processing of novel materials, helps to achieve scientific results faster. We report on our continuous effort to advance FIB technology along with an instrumentation platform dedicated to nanofabrication requirements.

The nanofabrication requirements for FIB technology are specific and more demanding in terms of stability, resolution, and the support of new processing techniques. To advance nanofabrication applications, we have improved gallium-based liquid metal ion source (LMIS) with a stable gun emission design enabling long-term stability without the need for frequent heating, and producing low drifts in probe current (Figure 1) and beam position.

Moreover, we report a FIB spot allowing excellent patterning resolution with low collateral damage.

This spot is usually not a pure Gaussian distribution, instead exhibiting significant beam tails, which have to be as small as possible for high resolution nanofabrication. In order to measure the beam current distribution we employed a method based on the amorphization of single crystal silicon by Gallium ions.

Compared with conventional LMIS FIB, the results here show a very narrow and large central Gaussian part and very low tails. As the most relevant part for -3 milling is in the dose range of 1 to 10 , this technology offers superior performance especially for nanofabrication. Combining this FIB technology with an instrumentation platform optimized for

nanometer scale patterning over large areas and extended periods of time applications such as X-ray zone plates [1], large area gratings [2], plasmonic arrays, and wafer-scale nanopore devices become possible.

Moreover the type of ion defines the nature of the interaction mechanism with the sample and thus has significant consequences on the resulting nanostructures. Therefore, we have extended the technology towards the stable delivery of multiple ion species selectable into a nanometer-scale focused ion beam by employing a liquid metal alloy ion source (LMAIS). A mass separation filter is incorporated into the column to allow for fast and easy switching between different ions or clusters within less than a minute [3,4,5]. This provides single and multiple charged species of different mass (Figure 2), e.g. Be, Si, Ge or Au, resulting in significantly different interaction mechanisms. We present and discuss the capabilities of the instrument for sub-20 nm to sub-10 nm nanofabrication (Figure 3) as well as potential applications. Using a Si ion beam for high resolution low contamination milling or a Au ion beam for surface functionalization will be given as examples for a full range of techniques yet to be explored.

References [1] A. Nadzeyka et al., Microelectr. Engineering 98 (2012), 198-201.

[2] S. K. Tripathi et al., J. Micromech. Microeng. 22 (2012) 055005.

[3] B. R. Appleton et al., Nucl. Instrum. Methods B 272, 153 (2012).

[4] S. Tongay et al., Appl. Phys. Lett. 100, 073501 (2012).

[5] S. Bauerdick et al., JVST B 31 (2013) 06F404.

76 | n a n o P T 2 0 1 5 P o r t o ( P o r t u g a l )

Figures

Figure 1: Probe current measurement of a Ga ion source over 67 hours 1100

Au

1000

+

900 800

current (pA)

700 600 500 400 300

Si

200

++

100

Si

0 0

Au

++ ++

Au3

+

100

200

300

+

Au2

400

mass (amu)

Figure 2: Mass spectrum of a AuSi ion source with various ion species.

Figure 3: Results for milling of a 40 nm gold layer on a bulk sample: 7 nm to 19 nm features obtained with a Be, Si and Au ion beam (from left to right) [5].

nanoPT2015 Porto (Portugal)

| 77

Ana I. S. Neves1,2, Luis V. Melo1,3, Saverio Russo1, Isabel de Schrijver4, Helena Alves1,5, 1 Monica F. Craciun 1 Centre for Graphene Science, College of Engineering, Mathematics and Physical Sciences, Univ. of Exeter, UK 2 INESC – Microsystems and Nanotechnology, Portugal 3 Physics Department, Instituto Superior Técnico, University of Lisbon, , Portugal 4 CenTexBel – Belgian Textile Research Centre, Belgium.

5 CICECO – Centre for Research in Ceramics and Composite Materials, University of Aveiro, Portugal

Graphene-coated transparent conducting fibres for smart textiles

a.neves@exeter.ac.uk

The development of electronic textiles is one of the hottest topics in organic electronics. There are already examples of smart textiles in garments for monitoring physiological and biomechanical signals. However, the manufacturing schemes for current applications rely mostly on the integration of off-the-shelf electronic components mounted on a textile substrate. Such components are silicon-based, thus unsuitable for applications where flexibility and fault-tolerance are required.

Organic electronics is an alternative to conventional silicon technology and can overcome those limitations. In this sense, graphene, with high optical transparency and electrical conductivity, is a promising material.

In the pursuit of conducting fibres, our approach consisted in coating specially designed nanosmooth polypropylene fibres with graphene.

Monolayer graphene was grown on copper foils by low pressure chemical vapour deposition using methane as a carbon source, and wet-transferred to the fibres after copper etching. Graphene adhesion to the fibres was found to be sensitive to minute surface modifications. In that sense, several surface treatments were tested and AFM microscopy was performed to evaluate the resulting changes in the surface of the fibres.

Raman spectroscopy confirmed the presence and quality of the graphene transferred onto the fibres, and optical measurements proved that the fibres remained transparent after the graphene coating. The I-V response of the fibres was measured with different curvatures, and the corresponding sheet resistance was found to be of the same order than monolayer graphene on

4

conventional silicon substrates, up to 10 Ω/sq.

Besides polypropylene, the study was successfully extended to Nylon commercial fibres.

Figures

Figure 1: Graphene-coated polypropylene fire closing an electric circuit that is powering a LED (graphite was applied to define the channel area).

78 | n a n o P T 2 0 1 5 P o r t o ( P o r t u g a l )

Jana B. Nieder INL - Internatioanl Iberian Nanotechnology Laboratory, Braga, Portugal jana.nieder@inl.int

Presentation of the New “Ultrafast Bio- and Nanophotonics” Laboratory at INL

A new laboratory devoted to light-matter interaction on the nanoscale is being set up at INL International Iberian Nanotechnology Laboratory.

We are going to present the different techniques, which are being implemented and developed to allow optical and magneto-optical sensitivities reaching into femtosecond and nanometer scales.

Fluorescence (lifetime) spectroscopy will be available to study e.g. the sensitivity of plasmonic biosensors. To obtain spatially resolved information of nanostructured material or biological samples, several imaging techniques, one of them reaching below the optical diffraction limit, are going to be implemented. To obtain 3D super-resolution sensitivity a concept developed last year by Chizhik et al. [1], based on the interaction of fluorophores with a thin metal film, shall be set up and further developed to allow for 3D multicolor life cell imaging.

References [1] “Metal-Induced Energy Transfer for Live Cell Nanoscopy“, A. I. Chizhik, J. Rother, I. Gregor, A. Janshoff, J. Enderlein, Nature Photonics 8, 124– 127 (2014)

Figures

Taking advantage of the available femtosecond laser, several techniques based on nonlinear interaction effects, such as multi-photon microscopy and 3D laser lithography will be made available.

For increased imaging contrast in multi-photon microscopy the pulse characteristics will be optimized, e.g. using supercontinuum generation in photonic crystal fibers (in collaboration with U Porto).

Figure 1: Visualization of techniques available and to be developed in the “Ultrafast Bio- and Nanophotonics” laboratory at INLInternational Iberian Nanotechnology Laboratory.

Optically detected magnetic resonance ODMR on color centers in nanodiamonds shall be used to develop a magnetometry technique with nanoscale sensitivity, e.g. to precisely characterize magnetic fields around ferromagnetic nanostructures or biological material, e.g. neurons.

nanoPT2015 Porto (Portugal)

| 79

Giovanni Onida, Nicola Manini, Nicola Ferri, Ivano Castelli Dipartimento di Fisica, Via Celoria 16, 20133 Milano, Italy

Carbon sp wires and their coupling to graphene

giovanni.onida@mi.infn.it

Carbon monoatomic wires, known as carbynes, have recently emerged as a novel form of nanostructured carbon which can be routinely synthesized [1] We present, as an evident demonstration of how far material properties can be changed by barely "nanostructuring" it, a series of theoretical and computational results about the mechanical, electronic, magnetic and vibrational properties of nanostructures based on sphybridized carbon [2-6]. We illustrate several implications for possible applications, including nanoelectronics, spintronics, and nano-sensing.

Figures

References [1] E. Kano, A. Hashimoto, M. Takeguchi, Microscopy and Microanalisys 20 (2014) 1742; E. Erdogan, I. Popov, C. G. Rocha, G. Cuniberti, S. Roche, and G. Seifert, Phys. Rev. B 83, (2011) 041401; C.Jin, H. Lan, L. Peng, K. Suenaga, and S. Iijima, Phys. Rev. Lett. 102 (2009) 205501; A. Chuvilin, J. C Meyer, G. Algara-Siller and U. Kaiser, New J. Phys. 11 (2009) 083019; [2] E. Cinquanta, N. Manini, L. Ravagnan L. Caramella, G. Onida, P. Milani, and P. Rudolf, J. Chem. Phys. 140 (2014) 244798.

[3] T.M. Mazzolari and N. Manini, J. Phys.: Condens.

Matter 26 (2014) 215302.

[4] I.E. Castelli, N. Ferri, G. Onida, and N. Manini, J. Phys.: Condens. Matter 24 (2012) 104019.

[5] I.E. Castelli, P. Salvestrini, and N. Manini, Phys.

Rev. B. 85 (2012) 214110.

[6] Zeila Zanolli, Giovanni Onida, and J.-C. Charlier, ACS Nano 4 (2010) 5174.

[7] L. Ravagnan, N. Manini, E. Cinquanta, G. Onida, et al., Phys. Rev. Lett. 102 (2009) 245502.

Figure 1: Some systems realized by carbon monoatomic wires, and their coupling to sp2 carbon: i) Structural snapshot from finitetemperature TBMD simulation; ii) example of a localized on-chain electronic state; iii) electronic structure showing Ď&#x20AC;-state magnetism.

80 | n a n o P T 2 0 1 5 P o r t o ( P o r t u g a l )

M. J. Pereira, J. S. Amaral, N. J. O. Silva and V. S. Amaral Departamento de FĂ­sica and CICECO, Universidade de Aveiro, Aveiro, Portugal

Scanning Thermal Microscopy: unraveling and mapping thermal phenomena at the nanoscale

mariasapereira@ua.pt

There has been growing interest in obtaining greater knowledge on heat transport phenomena in nanostructured materials, since they are often determinant for the performance of modern micro and nano-devices, such as sensors possessing nanosized features and thermoelectric nanomaterials.

Furthermore, nanoscale thermal properties assume great relevance in modern electronic circuits that dissipate power at the nanoscale.[1] Scanning thermal microscopy (SThM) is a powerful tool with a leading role concerning probing and mapping of local thermal properties of materials and heat generation with nanometric spatial resolution.

Based on an atomic force microscope (AFM), the SThM uses a specialized heated thermal probe designed to act as a thermometer instead of the conventional AFM tip. Since its invention, AFM revealed itself a fundamental mean for imaging and introducing features at the nanoscale that alter the structure and properties of the materials. Enabling self-heating on a conventional AFM tip paved the way for its implementation, in the form of Scanning Thermal Microscopy, not only in a wide variety of manufacturing and imaging applications with unmatched quality, but also as a leading technique in the search for thermal functional properties.

Determining and acting on the thermo-physical properties of microstructures is thus of great use in understanding/modelling heat transfer and macroscopic properties of heterogeneous materials.

As an example, the study of contrast thermal properties is especially important for the study of polymer composites and lithographed materials.

The fundamental feature of this technique, the SThM tip, is a nanofabricated thermal probe that can act as a resistance thermometer or a resistive heater, depending on the selected operation mode: passive mode or active mode, also known as temperature contrast mode (TCM) and (thermal) conductivity contrast mode (CCM), respectively. It is also possible to collect simultaneously surface topography image and thermal image of the samples under analysis due to the independent

nature of both AFM and SThM mechanisms in the same equipment (fig. 1).

Here we present exploration routes for the study of phenomena by Scanning Thermal Microscopy. Using a XE7 Scanning Probe Microscope with Scanning Thermal Microscopy from Park Systems [2], in this presentation we show the path for research in relevant topics, namely thermal conductivity of graphene layers deposited on different substrates by conductivity contrast, the electrocaloric or magnetocaloric effects in nanostructured materials.

Further work on inducing and studying structural phase transformations on thin films of functional materials with relevant properties for application in nano-devices, such as BaTiO3 and Ni2MnGa is also presented. Work in progress for this technique includes also its application to time dependent processes, bringing it forward as a contribution to otherwise complex analysis of dynamic processes.

Due to its high thermal conductivity and subsequent efficiency in heat conduction, graphene is noted as suitable candidate to aid overcome the obstacle of increasing dissipation power density arising from constant downscaling of electronic devices. In fact, grapheneâ&#x20AC;&#x2122;s excellent thermal properties, combined with highly interesting electronic and optical properties, recommend it for a wide range of applications in several fields. [3.] However, the mechanisms behind grapheneâ&#x20AC;&#x2122;s thermal properties still lack clarity. It has been shown that graphene monolayers possess high thermal conductivity, but the values obtained so far seem to vary according to the deposition method and measurement technique. SThM presents itself as a reliable technique to clarify the intriguing thermal properties of graphene monolayers (fig. 2), namely by enabling accurate estimation of the thermal conductivity of this material supported by different substrates, relying on thermal contrast between the graphene monolayer and other materials with known thermal conductivity [4].

The electrocaloric (EC) effect consists in the variation of temperature that some materials

nanoPT2015 Porto (Portugal)

| 81

experience under an applied electric field, which is enhanced at temperatures near ferroelectric phase transitions. [5] This is why EC is becoming an interesting alternative to refrigeration based on the magnetocaloric effect due to the economically inviable large magnetic fields that this effect requires. [6][7] Thin films exhibit especially high EC effects. However, direct measuring of EC in thin films is hard to accomplish due to the great difference between heat flow output shown by thin film and substrate. SThM solves this inconvenience, allowing direct measurement mapping of temperature changes in several spots of a thin film, enabling and promoting thus the search for promising materials for micro-scale cooling applications.

Acknowledgements This work is funded by FEDER through “Programa Operacional Factores de Competitividade” - COMPETE and by national funds through FCT - Fundação para a Ciência e Tecnologia with the projects HEAT@UA RECI/CTMCER/0336/2012 and PEst-C/CTM/LA0011/2013 (FCOMP-010124-FEDER-037271)

References [1] Volz, Sebastian, Rémi Carminati, Microscale and Nanoscale Heat Transfer, Berlin Springer (2007) 181-236 [2] http://www.parkafm.com [3] Alexander A. Balandin, Suchismita Ghosh, Wenzhong Bao, Irene Calizo, Desalegne Teweldebrhan, Feng Miao, Chun Ning Lau, Nano Lett., 8 (2008) 902–907 [4] Anton N. Sidorov, Daniel K. Benjamin, Christopher Foy, Appl. Phys. Lett., 103 (2013) 243103 [5] S. Kar-Narayan, S. Crossley, X. Moya, V. Kovacova, J. Abergel, A. Bontempi, N. Baier, E. Defay, N. D. Mathur, Appl. Phys. Lett., 102 (2013) 032903 [6] Dongzhi Guo, Jinsheng Gao, Ying-Ju Yu, Suresh Santhanam, Gary K. Fedder, Alan J. H. McGaughey, S. C. Yao, Appl. Phys. Lett., 105 (2014) 031906 [7] Xavier Moya, Enric Stern-Taulats, Sam Crossley, David González-Alonso, Sohini Kar-Narayan, Antoni Planes, Lluís Mañosa, Neil D. Mathur, Advanced Materials, 25 (2013) 1360–1365

Figures

Figure 1: Schematic showing the independent nature of both mechanisms for topographical and thermal images collection (adapted from Park Systems [2])

Figure 2: Left: topographical image of Si/graphene interfaces performed with thermal nanoprobe of SThM system; Right: SThM conductivity contrast image (CCM) of the area depicted on the left and line profile showing the contrast in thermal conductivity between graphene and Si

82 | n a n o P T 2 0 1 5 P o r t o ( P o r t u g a l )

Jimena A. Olmos-Asar1, Erik Vesselli2,3, Alfonso Baldereschi1 and Maria Peressi1,4 1

Physics Department, University of Trieste, Trieste, Italy 2 Physics Department and CENMAT, University of Trieste, Trieste, Italy 3 IOM-CNR Laboratorio TASC, Trieste, Italy 4 IOM-CNR DEMOCRITOS, Trieste, Italy

Seeding, nucleation and reactivity of alumina/Ni3Al(111) supported metallic nanoclusters: an ab-initio investigation

peressi@ts.infn.it

We investigate the mechanisms of seeding and nucleation of metallic nanoclusters onto an ultrathin alumina template supported on Ni3Al(111) (Figure 1a,b) by means of ab-initio density functional theory calculations. Many atoms (Fe, Co, Ni, Cu, Pd, Ag and Au) show preferential occupation of the defective sites of the ordered so-called “dot” structure of the oxide film (Figure 1c), where the adsorption is stronger than in the “network” or any other surface site. The relative strength varies with the atomic species, going from the large values of Pd and Ni to the low value of Ag. These results rationalize the experimental evidence showing that some metals such as Pd and Ni create highly ordered patterns of seeds and further nucleation of nanoclusters (Figure 2), whereas others, such as Ag, give rise to less ordered superstructures at room temperature [1].

We study then the interaction of carbon monoxide with a self-seeded ordered array of Cu nanoclusters, comparing simulations with in situ X-Ray Photoelectron Spectroscopy measurements.

Adsorption and dissociation of carbon monoxide occur at the copper clusters. The involved mechanisms are investigated at the atomic level, unveiling the effects of cluster finite size, reconstruction, support, and of local CO coverage. It is found that the high coverage of CO at the cluster surface, which considerably exceeds that achievable on single crystal surfaces, facilitates the metal restructuring and the reaction, yielding carbon incorporation into the bulk of the particles (Figure 3) [2,3].

[3] J. A. Olmos-Asar, E. Monachino, C. Dri, A. Peronio, C. Africh, P. Lacovig, G. Comelli, A. Baldereschi, M. Peressi, and E. Vesselli, CO on supported Cu nanoclusters: coverage and finite size contributions to the formation of carbide via the Boudouard process, submitted

Figures

Figure 1: a) Top view of the structural model of the Al2O3/Ni3Al(111) (O: red; Al: green; Ni: blue); the white circle around the “dot” defect highlights a reduced model considered for calculations. b) The periodically repeated unit cell. c) Top and side view of the equilibrium configurations for a monoatomic Cu seed in the “dot” defect.

Figure 2: Side view of the equilibrium configurations for a 15-atom Cu nanocluster nucleated in the “dot” defect of alumina/Ni3Al film.

References [1] J. A. Olmos-Asar, E. Vesselli, A. Baldereschi and M. Peressi, in preparation [2] J. A. Olmos-Asar, E. Vesselli, A. Baldereschi, and M. Peressi, Self-seeded nucleation of Cu nanoclusters on Al2O3/Ni3Al(111): an ab-initio investigation, Physical Chemistry Chemical Physics 16 (2014) 23134-23142.

Figure 3: A small Cu unsupported nanocluster covered by CO molecules and a possible resulting configuration after reaction of two molecules.

nanoPT2015 Porto (Portugal)

| 83

M.J. Perez-Roldan1, F. Tatti2, A. Berger1, A. Chuvilin1,3 1 CIC nanoGUNE Consolider, Donostia-San Sebastian, Spain.

2 FEI Electron Optics Eindhoven, The Netherlands.

3 Ikerbasque, Basque Foundation for Science, Bilbao, Spain

One step FEBID fabrication of Co based magnetic nanotubes

mj.perez@nanogune.eu

Focused electron beam induced deposition (FEBID) is a well-known direct-writing technique that has been widely studied in the last decades due to its versatility as micro and nanofabrication tool [1, 2].

Most recently, the deposition in parallel of two different precursors has also called the attention of several researchers in order to grow binary alloys [36]. In these alloys the relative flux of the two precursors was varied in order to tune the bulk composition and confer to the deposits different electric and magnetic properties.

[4] Porrati, F., et al., J. Appl. Phys. 113, 053707, (2013).

[5] Winhold, M., et al., ACS Nano. 5, 9675, (2011).

[6] Che, R.C., et al., Appl. Phys. Lett. 87, 223109, (2005).

Figures

In this work, binary systems of Co-SiOx in a carbonaceous matrix has been deposited using dicobalt octacarbonyl (Co2(CO)8) and tetraethyl orthosilicate (Si(OC2H5)4) precursors. Planar crosssections of deposited pillars were prepared and the composition distribution was investigated by energy dispersive X-ray spectroscopy (EDX) maps. Magnetic characterization was performed by Lorentz microscopy.

Results showed a non-homogeneously distributed composition inside the FEBID pillars but a symmetric radial distribution, as can be seen in Figure 1a) where the EDX map of the cobalt element in showed. Moreover, Lorentz microscopy showed a magnetic behaviour localized on the areas with the highest cobalt content, see Figure 1b).

Hence, we report in this work a single step nanofabrication process of magnetic nanotubes.

References

Figure 1: a) EDX map of Cobalt distribution on the pillar and b) contour lines showing themagnetic flux distribution in the pillar.

[1] Huth, M., et al., Beilstein J. Nanotechnol. 3, 597â&#x20AC;&#x201C;619, (2012).

[2] Utke, I., et al., J. Vac. Sci. Technol. B 26, 1197, (2008).

[3] Porrati, F., et al., Nanotechnology. 23, 185702, (2012).

84 | n a n o P T 2 0 1 5 P o r t o ( P o r t u g a l )

Joana Fontes Queiroz, Ana Rute Neves, Sofia A.Costa Lima and Salette Reis

New insights in the development of solid lipid nanoparticles for active brain-targeted drug delivery

REQUIMTE, Department of Chemical Sciences, Faculty of Pharmacy, University of Porto, Porto, Portuga fontes_joana@hotmail.com

The challenging of cross the blood-brain barrier (BBB) and reach the brain in an appropriated therapeutic concentration is the Holy Grail for effectively treat and cure brain diseases. The BBB is not only a physical barrier, it constitutes a dynamic, semi permeable and highly selective barrier that protects and supplies the brain. However the BBB represents a considerable obstacle to brain entry of the majority of drugs and thus severely restricts the therapy of many brain diseases including brain tumors, brain HIV, Alzheimer and other neurodegenerative diseases. The traditional drug delivery systems with no brain targets release the drugs in systemic circulation failing the delivery into the brain. Therefore, there is a huge need to develop and design approaches with specific target to brain in a better and more effective way for the treatment of brain diseases. Here, the nanotechnology can be an important tool to improve the specificity and permeability of drugs in the BBB [1].

In this work we developed a new delivery system to direct drugs to the brain, by functionalizing solid lipid nanoparticles (SLNs) with apolipoprotein E (Apo E), aiming to enhance their binding to low-density lipoprotein (LDL) receptors overexpressed on the BBB endothelial cells.

SLNs were successfully functionalized with Apo E, using two distinct strategies which took advantage of the strong interaction between biotin and avidin.

The functionalization of SLNs with ApoE was demonstrated by infrared spectra and fluorimetric assays. Transmission electron microscopy (TEM) images revealed spherical nanoparticles, dynamic light scattering (DLS) gave a Z-average under 200 nm, polydispersity index below 0.2 and zeta potential between -10 mV and -15 mV. A stability study revealed that these characteristics remained unchanged for at least 6 months. In vitro cytotoxic effects were evaluated by MTT and LDH assays in the hCMEC/D3 cell line, a human BBB model, and revealed no toxicity up to 1.5 mg/ml for 4 hour of

incubation. The BBB permeability was also evaluated in transwell devices with hCMEC/D3 monolayers and it was found a 1.5-fold increase in the permeability of functionalized SLNs when compared with nonfunctionalized ones.

In order to clarify the transport pathways of the nanoparticles through the BBB, the different molecular mechanisms of endocytosis and transcytosis processes were carefully studied using flow cytometry system (FCS), confocal laser scanning microscopy (CLSM) and fluorimetric assays with tracers and different pathway inhibitors. The transport of SLNs across the hCMEC/D3 monolayer was found through a transcellular but not a paracellular route. Functionalized SLNs exhibited higher intracellular uptake compared with nonfunctionalized ones and were found to enter the cells through a specific clathrin-mediated mechanism, related to the expression of LDL receptors on BBB. The results suggested that these novels ApoE-functionalized SLNs resulted in dynamic stable systems capable of being used for an improved and specific brain delivery of drugs through the BBB. Acknowledgments ARN acknowledges the FCT for financial support through the Ph.D. grant (SFRH/BD/73379/2010). The authors are greatly indebted to financing sources of EU through the Project ON2, NORTE-07-0124FEDER-000067 and from FCT through the project Pest-C/EQB/LA0006/2013.

References [1] Kaur I. P.; et al., Journal of Controlled Release.

Potential of solid lipid nanoparticles in brain targeting (2008) 127, 97-109.

nanoPT2015 Porto (Portugal)

| 85

Sohel Rana1, Shama Parveen1, Raul Fangueiro1, Maria Conceição Paiva1, JosÊ 2 Xavier 1 University of Minho, Campus de Azurem, Guimaraes, Portugal 2 INEGI, FEUP, University of Porto, Porto, Portugal

Development of Ductile Cementitious Composites Using Carbon Nanotubes

soheliitd2005@gmail.com

Concrete is the primary construction material for civil infrastructures and generally consists of cement, coarse aggregates, sand, admixtures and water. Cementitious materials are characterized by quasi-brittle behaviour and susceptible to cracking [1]. The cracking process within concrete begins with isolated nano-cracks, which then conjoin to form micro-cracks and in turn macro-cracks.

Formation and growth of cracks lead to loss of mechanical performance with time and also make concrete accessible to water and other degrading agents such as CO2, chlorides, sulfates, etc. leading to strength loss and corrosion of steel rebars. To improve brittleness of concrete, reinforcements such as polymeric as well as glass and carbon fibers have been used and microfibers improved the mechanical properties significantly by delaying (but could not stop) the transformation of microcracks into macro forms [2]. This fact encouraged the use of nano-sized fillers in concrete to prevent the growth of nano-cracks transforming in to micro and macro forms. Nanoparticles like SiO2, Fe2O3, and TiO2 led to considerable improvement in mechanical performance and moreover, nano-TiO2 helped to remove organic pollutants from concrete surfaces [3].

Nanomaterials with exceptional properties like carbon nanotube (CNT) [4] have been incorporated within cementitious matrix to improve mechanical performance and toughness and to introduce electrical conductivity and piezoresistivity [1].

Additionally, in nano-scale, CNTs exhibited the possibility to restrict the growth of nano-cracks through crack-bridging mechanism, thereby, enhancing the durability of concrete. However, the improvement of above properties was found strongly dependant on the dispersion of CNT within cementitious matrix and improper dispersion and agglomeration even resulted in

deterioration of various properties. Therefore, there exists an enormous need for an efficient dispersion route to achieve homogeneous CNT dispersion and besides mechanical treatments (ultrasonication, stirring), various chemical dispersants (surfactants and polymers) have been suggested to prepare well dispersed CNT aqueous suspensions for mixing with cement [1].

The present paper reports the use of a novel dispersant (Pluronic F-127) to disperse CNTs in water and subsequently within cementitious matrix and the fracture behaviour of the resulting cementitious composites. CNT/water suspensions with different CNT concentrations were prepared using a short ultrasonication process (1 hr) with the help of Pluronic F-127 at optimum concentrations, and the suspensions were then mixed with cement/sand mixture to develop cementitious composites. The fracture behaviour was studied using single-end notched bending (SENB) specimens in the 3 point bend configuration and measuring the crack propagation parameters (such as crack length, crack-tip opening displacements, etc.) using digital image correlation technique (DIC). Fracture energy and toughness were then calculated using these parameters.

The load-displacement curves of plain mortar and CNT/mortar samples are presented in Figure 1. It is very clear from these graphs that the samples containing CNTs showed significantly higher breaking strain and ductility as compared to plain mortar specimens. The cementitious composites containing 0.1 wt. % single walled nanotubes (SWNTs) and 0.15 wt. % multi-walled nanotubes (MWNTs) resulted in 109% and 96% improvements in the fracture energy of plain mortar specimens, respectively. Fracture surface study using Scanning Electron Microscopy (SEM) suggested that CNTs

86 | n a n o P T 2 0 1 5 P o r t o ( P o r t u g a l )

were tightly inserted between the hydration products of cement and showed bridging of cracks to prevent quick propagation of cracks and opening of crack mouth, resulting in higher fracture energy and ductility.

References [1] Parveen S, Rana S, Fangueiro R, Journal of Nanomaterials, 2013 (2013) 1-19.

[2] Akkaya Y, Shah SP, Ghandehari M, ACI Special Publications, SP 216 (2003) 1-18.

[3] Qing Y, Zenan Z, Deyu K, Construction and Building Materials, 21 (2007) 539-545.

[4] Rana, S, Alagirusamy R, Joshi M, Journal of Reinforced Plastics and Composites, 28 (2008) 461-487.

Figures

Figure 1: Load-displacement curves of notched samples of plain mortar and CNT/mortar composites, tested at 3 point bending configuration

nanoPT2015 Porto (Portugal)

| 87

Cláudia D. Raposo1,2, Krasimira T. Petrova2, M. Margarida Cardoso2 1

IBET, Av. República, Quinta do Marquês Estação Agronómica Nacional, Oeiras, Portugal 2 REQUIMTE, CQFB, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Caparica, Portugal

Synthesis of novel galactose-PLGA nanoparticles containing doxorubicin for hepatocyte targeting

piccfa@gmail.com

One of the major goals within cancer therapies is to increase drug concentration in the tumor, decrease the systemic dose and, at the same time, attack only cancer cells. Drug delivery systems able to target specific cells/tissues due to recognition processes could be one of the solutions. These systems can therefore increase the drug at the active site, decrease therapeutic quantities, increase efficiency and reduce toxicity [1].

To treat liver diseases, it is possible to synthetize galactose conjugates for specific recognition by the asialoglycoprotein receptor (ASGPR) in hepatocytes.

ASGPR recognizes terminal galactose or Nacetylgalactosamine residues, which makes ASGPR a potential target to the liver [2]. Our study is focused on the synthesis of di-galactose compounds to evaluate their interaction with ASGPR in order to use these ligand as a hepatocyte recognition unit.

These compounds will be covalently attached to a biocompatible polymer [3] that will be used to produce nanoparticles containing an encapsulated drug. The produced nanoparticles should have an amphiphilic structure that allows the drug capture in the hydrophobic center (biopolymer part) whilst the outside of the nanoparticle is hydrophilic, with galactose residues for the ASGPR. Under this context, we present the synthesis of a digalactose-PLGA conjugate that is subsequently used to prepare nanoparticles containing doxorubicin.

The produced nanoparticles are characterized in terms of morphology and size, drug release profile and cellular recognition and cell cytotoxicity using human hepatoma cells (Hep G2), a suitable in vitro model for the study of galactose interaction with asialoglycoprotein receptors.

Aknowledgements The authors aknowledge Fundação para a Ciência e Tecnologia (Portugal) for financial support through project PTDC/EQU-EPR/119631/2010.

References [1] W. Lin, M. Chen, Carbohydr. Polym. 67 (2007) 474-480.

[2] M. Meier, M. Bider, V. Malashkevich, M. Spiess, P. Burkhard, J. Mol. Biol. 300 (2000) 857-865.

[3] I.F. Uchegbu, A.G. Schätzlein, Polymers in drug delivery, CRC, Boca Raton, Fla. ; London, 2006.

Figures

Figure 1. SEM image of the produced di-galactose-PLGA nanoparticles

88 | n a n o P T 2 0 1 5 P o r t o ( P o r t u g a l )

Transparent aluminum nanowires electrodes with optical and electrical anisotropic response fabricated by defocused ion beam sputtering

Diego Repetto, Maria Caterina Giordano, Christian Martella, Francesco Buatier de Mongeot Physics Department, University of Genoa, Italy diegorepet@gmail.com

Self-organized Ion Beam Sputtering (IBS) can lead to the formation of ordered metallic nanowire (NW) arrays by direct IBS patterning of a metal film supported on a flat low cost glass substrate. For increasing ion dose, the rippled metal film decomposed into a disconnected NW array which exhibits tunable anisotropic optical properties as well as anisotropic electrical conductivity. So far, for the metal sacrificial layer, noble metals as Au [1,2] or Ag [3] were chosen since, beyond having a very low resistivity, they support localized plasmon resonances in the VIS-NIR spectral range [1,2].

References [1] D. Chiappe, A. Toma, and F. Buatier de Mongeot, Phys. Rev. B 86, 045414 (2012) [2] D. Chiappe, A. Toma, and F. Buatier de Mongeot, Small 9, 913-919 (2013) [3] A. Toma et al., Journal of Applied Physics 104, 104313 (2008)

In this work, we have explored the possibility to find an alternative to transparent conductive oxides in optoelectronic devices. In this view, self-organized Al NWs electrodes have been obtained by defocused IBS of polycrystalline Al films grown by sputter deposition, adopting experimental conditions which are compatible with industrial processes, in view of the fabrication of low cost transparent electrodes.

The electrical characteristics have been acquired in situ during the morphological evolution of the samples, evidencing an increase of the electronic transport anisotropy as a function of ion dose between the two directions parallel and orthogonal to the NWs axis.

Optical spectra in transmission also show a large dichroism between the two directions, suggesting the role of localized plasmons in the UV spectral 18 2 range. After a fluence of 1,2 x 10 ions/cm , the Al NWs electrodes showed transparencies of about 40% and sheet resistances, longitudinal and transverse, of 18 立sq and 4,5 立sq. At higher fluences, higher transparencies are obtained at the expense of conductivity.

nanoPT2015 Porto (Portugal)

| 89

D. Ribeiro1, A. C. Alves1, C. Nunes1, S. Reis1 1 REQUIMTE, Departamento de Ciências Químicas, Faculdade de Farmácia, Universidade do Porto, Porto, Portugal

Characterization of Model Membranes under the Effect of Anticancer Drugs

danielapintribeiro@gmail.com

Cancer is a pathology that affects a large portion of the world’s population [1]. It is an assembly of diseases with various symptoms that significantly decreases the patient’s life quality and has a high rate of mortality [2]. One of the most commonly used treatments for this pathology is chemotherapy, involving the use of combinations of drugs to kill cancer cells. Since these drugs either act directly on the membrane or have to cross it to reach their targets, the interactions between anticancer drugs and biological membranes are of high importance.

The structure of biological membranes consists of a phospholipid bilayer.

In healthy cells, phosphatidylcholine (PC) and phosphatidylserine (PS) are some of the most common lipids, the PS being found on the inner leaflet, but cancer cells’ membranes usually present higher heterogeneity in constitution and the PS exposed to the extracellular media [3]. The complexity of the membrane and all the variables associated with the cells’ functions makes it a very difficult model to study. As such, artificial model membranes like liposomes might present a viable alternative, being a simpler and easier to manipulate model that accurately simulates the cell membrane’s constitution and behaviour.

That being said, the aim of our study was to assess the effects of two anthracyclines used in chemotherapy, daunorubicin and doxorubicin, on the lipid membranes of four LUV formulation models, two of them constituted by DMPC with and without cholesterol, mimicking the normal cell membrane, and the other two simulating the tumoral cell membrane, constituted by a mixture of DMPC:DOPC:DPPS (3:1:1) also with and without cholesterol. Hepes buffer at pH 7.4 and Tris buffer at pH 6.3 were used to mimic the normal and tumoral tissue’s external pH, respectively. The effects of the drugs on the different models were assessed by size and zeta potential measurements, partition coefficient (Kp) determination, drug location and

membrane fluidity studies. The four formulations were then validated as model membranes for healthy cells and cancer cells. This was achieved through the study of similar properties in lines of healthy and cancer cells under the influence of the same drugs.

Acknowledgements Catarina Alves and Cláudia Nunes thank FCT (Lisbon) for the fellowships (SFRH/BD/82443/2011 and SFRH/BPD/81963/2011), respectively. This work received financial support from the European Union (FEDER funds through COMPETE) and National Funds (FCT, Fundação para a Ciência e Tecnologia) through project Pest-C/EQB/LA0006/2013. The work also received financial support from the European Union (FEDER funds) under the framework of QREN through Project NORTE-07-0124-FEDER-000067 .To all financing sources the authors are greatly indebted.

References [1] Singh, S., Pharmacology for Dentistry 1st ed.

Apr, 2007: New age International.

[2] ACS. American Cancer Society - Information and Resources for Cancer: Breast, Colon, Lung, Prostate, Skin. 2014 [cited 2014; Available from: http://www.cancer.org.

[3] Peetla, C., A. Stine, and V. Labhasetwar, Biophysical interactions with model lipid membranes: applications in drug discovery and drug delivery. Mol Pharm, 2009. 6(5): p. 1264-76.

90 | n a n o P T 2 0 1 5 P o r t o ( P o r t u g a l )

Ángel Ríos, Gema M. Durán, Ana M. Contento Department of Analytical Chemistry and Food Technology, University of Castilla-La Mancha, Ciudad Real, Spain A.Rios@uclm.es

Quantum dots (QDs) are colloidal semiconductor nanocrystals with a diameter typically in the range from 1 to 10 nm and exceptional physic-chemical properties. Their use, for different purposes has increased in the last years, especially in the development of new methods of analysis. Thus, their use for the development of optical sensors is one of the most developing fields of nanotechnology so far. Several works have demonstrated their optoelectronic properties based on changes on the QDs photoluminescence, significantly influenced by changes on the QDs surface charge or ligands that affect electron-hole recombination. However, most of analytical applications involve the use of biocompatible QDs with aqueous media. In this way, the colloidal synthesis route of QDs [1] is the most used due to the formation of high quality QDs nanocrystal and their long storage time. Therefore, the development of methodologies to allow the aqueous compatibly of QDs is necessary.

For this purpose, the aim of this communication is to show several alternatives involving the modification of the QDs surface and the affinity by the aqueous media, without significantly modifications in their initial properties and the subsequently analytical applications (Figure 1).

On the one hand, a simple and fast procedure for water solubilization of CdSe/ZnS QDs using microwave irradiation was optimized [2]. For this purpose, the replacement of initial hydrophobic ligands (TOPO/TOP) with different hydrophilic heterobifunctional thiol ligands, as L-cysteine, 3mercaptopropionic acid and cysteamine were carried out in a simple and fast way (only 40 s).

Thus, the solubilization and the surface modification of QDs were achieved for subsequently analytical applications. For instance, the particular reactions with different sulphonylurea herbicides were exploited.

New approaches in the development of analytical methodologies involving the use of CdSe/ZnS quantum dots

On the other hand, the use of water soluble CdSe/ZnS QDs for sensitive detection and quantification of paraquat in water samples was carried out [3]. It was found that 3-MPA modified CdSe/ZnS is sensible to the presence of paraquat.

The proposed analytical method thus satisfies the need for a simple, sensible and rapid methodology to determine residues of paraquat in water samples, as required by the increasingly strict regulations for health protection introduced in recent years. The sensitivity of the method, expressed as detection -1 limits, was as low as 3.0 ng L . The lineal range was -1 between 10- 5x103 ng L . RSD values in the range of 71-102% were obtained. The analytical applicability of proposed method was demonstrated by analyzing water samples from different origins.

In addition, an optical sensor for vanillin in food samples using CdSe/ZnS quantum dots (QDs) modified with β-cyclodextrin (β-CD) was developed [4]. This vanillin-sensor is based on the selective host-guest interaction between vanillin and β cyclodextrin. The procedure for the synthesis of β cyclodextrinCdSe/ZnS (β-CD-CdSe/ZnS-QDs) complex was optimized, and its fluorescent characteristics are reported. It was found that the interaction between vanillin and β-CD-CdSe/ZnS QDs complex produced the quenching of the original fluorescence of β-CD-CdSe/ZnS-QDs according to the Stern-Volmer equation. The analytical potential of this sensoring system was demonstrated by the determination of vanillin in synthetic and food samples. The method was selective for vanillin, with -1 a limit of detection of 0.99 μg mL , and a reproducibility of 4.1% in terms of relative standard deviation (1.2% under repeatability conditions).

Recovery values were in the 90-105% range for food samples. Recent promising results can been obtained by the electrophoretic separation involving the use of β-CDCdSe/ ZnS-QDs with different vanillin related compounds and their tandem detection by DAD-FD-ELSD. Other alternative has been the

nanoPT2015 Porto (Portugal)

| 91

development of a continuous flow method involving the CdSe/ZnS QDs. The main innovation in this work is the high throughput, the level of automation, the low consumption of reagents, and the low wastes generation. This application takes the exceptional optical properties of β- CD-CdSe/ZnS QDs for the determination of ascorbic acid in different fruit juices and pharmaceutical preparations.

Finally, the need to develop new methodologies that allow screening for compounds of interest in various areas without the need to use sophisticated instrumentation and an exhaustive determination using inexpensive portable device open new approach for screening methods. For this purpose, the fabrication of simple and economical colloidal CdSe/ZnS quantum dots (QDs)-modified paper device, constituttes and exceellent trend. This new appproach for screening methods demonstrates that QDs canbe used as probes for developing a new generation of paper-based analytical applications.

Acknowledgements Financial support from the Spanish Ministry of Economy and Competitiveness (CTQ2013-48411-P) is gratefully acknowledged References [1] Z.A. Peng, X. J. Peng, J. Am. Chem. Soc., 123 (2001) 183 [2] G. M. Duran, M. R. Plata, M. Zougagh, A M. Contento, and A. I. Rios. J. Colloid Interface Sci. 428 (2014) 235 [3] G. M. Duran, A. M. Contento, and A. Rios, Anal.

Chim. Acta. 801 (2013) 84 [4] G. M. Duran, A. M. Contento, and A. Rios, Talanta, 131 (2015) 286

Figures

Figure 1. Approaches for the modification and analytical applications of quantum dots.

92 | n a n o P T 2 0 1 5 P o r t o ( P o r t u g a l )

C.M.M. Rosário1, O.N. Gorshkov2, A. Kasatkin2, I. Antonov2, D. Korolev2, A.N. Mikhaylov2, N.A. Sobolev1,3

Resistive switching and impedance spectroscopy in metal-oxide-metal trilayers with SiOx and ZrO2: a comparative study

1

Departamento de Física and I3N, Universidade de Aveiro, Portugal 2 Lobachevsky State University of Nizhni Novgorod, 0 Russia 3 National University of Science and Technology “MISiS”, Moscow, Russia cmiguelrosario@ua.pt

The ReRAM, acronym of resistive (switching) random access memories, are candidates to lead the new generation of non-volatile memories and are based on a phenomenon known as resistive switching (RS) [1]. The research on this phenomenon, known since the 1960’s [2], was boosted by the link to the memristor, a passive fundamental circuit element proposed by Leon Chua in 1971 [3], demonstrated by a group of the HP Labs in 2008 [4]. Although the titanium dioxide is considered a prototypical memristive material [5], research on RS in structures containing materials that are compatible with the CMOS technology, nowadays the leading technology in the fabrication of integrated circuits, such as silicon oxide or zirconium oxide, may favour the future market introduction of RS-based devices.

In this work, Au/oxide/TiN structures, obtained by RF-magnetron sputtering deposition of 40 nm thin films of silicon and zirconium oxides, were investigated by means of current-voltage (I-V) characteristics and impedance spectroscopy and compared based on the results obtained.

In the SiOx structure, the I-V characteristics exhibit bipolar-like RS, with a ratio between the resistances of the high resistance state (HRS) and 2 the low resistance state (LRS) bigger than 10 , at 1 V read voltage. The observed RS is sensitive to the Au electrode exposure to the atmosphere, which enhances the RS (see Fig. 1). A decrease in the voltage application time leads to an increase in the voltage required to induce the transition from HRS to LRS. The two different states show a very distinct behaviour as the temperature is varied: whereas the LRS's resistance has a very weak temperature dependence and decreases with decreasing temperature, in the HRS the resistance

increases as the temperature drops. The latter state's resistance temperature dependence is described by a thermal activation of charge carriers, with activation energies of 0.46 and 4.3 meV in the 6 to 130 K temperature region. The weak dependence of the resistance with the Au electrode area and the invariance of the structure's capacitance between the states suggest a filamentary mechanism for the observed RS. Due to the oxygen's influence on the RS, the creation and disruption of the filaments should involve redox reactions.

The ZrO2 structures also exhibit bipolar-like RS, 2 with a ratio of ca. 10 between the resistance of the HRS and of the LRS, read at 1 V. However, the atmospheric exposure decreases the above mentioned ratio, having the opposite effect on the RS, relatively to the SiOx case (see Fig. 2). The increase in this ratio via pulsed measurements evidences the existence of at least two competing processes in the RS. The impedance spectra show a similar behaviour between these structures and the SiOx ones, even though there is a bigger dependence on the electrode area, behaviour that deviates from a single filament model. The addition of a germanium oxide (GeOx) layer between the Au electrode and the ZrO2 film enhances the repeatability of the I-V characteristics.

nanoPT2015 Porto (Portugal)

| 93

References [1] D. S. Jeong, R. Thomas, R. S. Katiyar, J. F. Scott, H. Kohlstedt, A. Petraru, C. S. Hwang, Rep. Prog.

Phys., 75 (2012): 076502.

[2] T. W. Hickmott, J. Appl. Phys., 33 (1962): 2669– 2682.

[3] L. Chua, IEEE Trans. circuit theory, CT-18 (1971): 507 – 519.

[4] D. B. Strukov, G. S. Snider, D. R. Stewart, R. S. Williams, Nature, 453 (2008): 80–83.

[5] K. Szot, M. Rogala, W. Speier, Z. Klusek, A. Besmehn, R. Waser, Nanotechnology, 22 (2011): 254001.

Figures

Figure 2: Typical I-V characteristics obtained for the Au/ZrO2/TiN structures with a voltage sweep rate of ca. 1 V/s (for the data shown with the circular symbols). The data displayed with the empty symbols was measured with a 300 nm-SiO2 mask covering the Au electrode, evidencing the impact of the atmospheric exposure for the RS process, in this case decreasing the resistance ratio between the high resistance state (HRS) and the low resistance state (LRS). The data displayed with the triangular symbols were measured in a pulsed regime (with a voltage sweep with 500 μs pulses for each voltage level, intercalated with a time interval where there was no applied voltage), which enabled a higher resistance ratio even without the mask. The red dashed arrow indicates the initial direction of measurement.

Figure 1: Typical I-V characteristics obtained for the Au/SiOx/TiN structures with a voltage sweep rate of ca. 1 V/s. The data displayed with the empty symbols was measured with a 300 nm-SiO2 mask covering the Au electrode, evidencing the importance of the atmospheric exposure for the RS process in increasing the resistance ratio between the high resistance state (HRS) and the low resistance state (LRS). The red dashed arrow indicates the initial direction of measurement.

94 | n a n o P T 2 0 1 5 P o r t o ( P o r t u g a l )

Choon-Ming Seah1,2, Brigitte Vigolo1, Siang-Piao Chai3, Abdul Rahman Mohamed2 1 Institut Jean Lamour, CNRS-Université de Lorraine, Vandoeuvre-lès-Nancy, France 2 School of Chemical Engineering, Engineering Campus, Universiti Sains Malaysia, Nibong Tebal, Seberang Perai Selatan, P. Pinang, Malaysia 3 Chemical Engineering Discipline, School of Engineering, Monash University, Jalan Lagoon Selatan, Selangor, Malaysia

An Improved Wet Chemical Approach For The SeparationOf Graphene From Nickel Foil To The Reutilization Of Catalyst

seahchoonming@yahoo.com

Chemical Vapor Deposition (CVD) is the most widely studied approach for the synthesis of wafer scale graphene. To fully utilize the magnificent properties of the graphene, the separation of graphene from the metal catalyst is important. To date, majority of the studies utilizing the wet chemical etching method that scarifying the metal catalyst in order to obtain free standing graphene. In order to realize the re-use of catalyst for minimization of the waste, an improved simple wet chemical etching method approach is proposed. Nickel has relatively high carbon solubility under elevated temperature as compared with other catalyst. Part of the carbon dissolved in the bulk nickel was not been used for the formation of graphene and later reacted with nickel to form nickel carbide crystal. After CVD, the

nickel foil with graphene was floated onto iron 3 nitrate solution with concentration of 1 mol/dm , an etching agent. The etching agent would intercalate between graphene and nickel to etch the surface of nickel for separation under slower rate. The inertness of nickel carbide would act as the protective layer to slowdown the chemical attack onto the bulk nickel foil and preserve it. The remaining nickel foil after the separation was used for same CVD and separation process to obtain another layer of graphene. A nickel foil with a thickness of 125μm can be reused to synthesis up to 6 pieces of graphene without large deviation in properties.

nanoPT2015 Porto (Portugal)

| 95

Bea Salesa, Ana V. Sánchez-Sánchez, José Luis Mullor, Juan Manuel Serrano Sesderma Laboratories, Polígono Industrial RafelbuñolC/Massamagrell 3, RafelbuñolBionos Biotech, Biopolo La Fe, Valencia, Spain

Repair Of UV Light-Induced Dna Damage

j.serrano@sesderma.com

Human skin exposure to ultraviolet (UV) radiation promotes DNA damage, which gives rise to aging, mutations, cell death and the onset of carcinogenic events. UV radiation introduces different types of damage into the DNA, being predominant the formation of cyclobutanepyrimidine dimers (CPDs) by covalent linkage between two adjacent pyrimidine nucleotides. Generation of CPDs is critical for photocarcinogenic processes, because they distort the DNA helix and are linked to mutations in tumour-suppressor genes expressed in skin cancer, such as gene p53.

Fish Medaka (Oryzias latipes) is a vertebrate model organism used in research. It is easy to handle and ideal for the screening of new functional compounds due to their large number of progeny per generation. Moreover, it offers the advantage of performing the functional assays “in vitro” when used in the eleutheroembryo phase. We must remark that all the experiments were carried out in vitro using eleutheroembryos.

In this study we evaluated whether DNA repair, in UV-irradiated Medaka eleutheroembryos, could be enhanced through topical application of a preparation containing DNA repair enzymes, amino acids, teprenone and Zn+ (EZ). In order to enhance nuclear delivery, each ingredient was encapsulated individually into liposomes.

Liposomes are small vesicles composed of one or more lipid bilayers, which improve bioavailability of active ingredients and provide a sustained release.

Their structure is very similar to biological membranes and thus, are biodegradable and non toxic. Moreover, they show higher efficiencies at lower concentrations and prevent oxidation and degradation of the ingredients.

All the liposomes used, were manufactured by Sesderma and had the following characteristics: Size between 50 and 150 nm, Polidispersity Index below

0.2, and Z potential between [30] and [150] mV (Delsa Nano C, Particle Analyzer).

Results We assayed endogenous DNA repairing mechanism in cells from Medaka fish embryos by measuring the reduction of CPDs, after UV irradiation (fig.1A).

Subsequently, by comparing the amount of CPDs formed immediately after UV light irradiation on cells treated with a control formulation (EZ minus active ingredients) and cells treated with EZ, we observed a significant decrease (36%) in the formation of CPDs (fig. 1B). p53 helps preventing genome mutation, due to its crucial role in regulating cellular responses to various DNA-damaging agents, including UV radiation. p21 is directly linked to p53 because its expression is tightly controlled by the protein p53.

We also studied the effect of UV light in the expression levels of p53 and p21 by comparing samples with or without irradiation. We found that the expression levels of p53 and p21 did not change in embryos not irradiated or embryos irradiated with UV light at t=0 minutes or t=15 minutes (fig 2A, C) indicating that at 15 min a p53- mediated response is not yet active. On the other hand, we observed that EZ treatment reduced the endogenous level of p53, allowing for an early damage response to UV light (t=15 min after UV irradiation) increasing the levels of p53. This early response induced by EZ treatment provoked in turn an increase in p21 expression of 130% as early as 15 min after irradiation (fig 2B, D). c-Fos is required for excision repair processes triggered by DNA lesions produced by UV radiation.

Therefore, we measured c-Fos expression level in control embryos and embryos treated with EZ, exposed or not to UV light. Results show that c-Fos does not significantly increase 15 minutes after UV radiation in control embryos (fig. 3A). On the the contrary, 15 minutes after UV radiation c-Fos is

96 | n a n o P T 2 0 1 5 P o r t o ( P o r t u g a l )

overexpressed in embryos previously treated with EZ (fig. 3B). In addition, we measured cell cycle immediately after irradiation with UV light and 15 minutes post irradiation, and we found that there were no significant changes in cell distribution in each cell cycle phase (fig. 4A, C, E). Furthermore, we measured cell cycle immediately after UV light irradiation on cells treated with the control preparation and embryos treated with EZ, and we did not observe any significant changes in cell distribution (fig. 4B, D, F) further indicating that the above gene expression changes detected, were not a consequence of changes in the cell cycle.

Conclusions Results indicate that EZ protects cells against UV light-induced damage through reducing the amount of CPDs in the DNA and triggers the endogenous DNA repair mechanisms that involve the action of p53, p21 and c-Fos.

[12]

[13] [14]

[15]

[16] [17]

References [1] Yarosh DB. DNA repair, immunosuppression, and skin cancer. 2004. Cutis.74(5 Suppl):10-13.

[2] Karakoula A, Evans MD, Podmore ID, Hutchinson PE, Lunec J, Cooke MS. Quantification of UVR-induced DNA damage: global- versus gene-specific levels of CPDs. J Immunol Methods. 2003 Jun 1; 277(1-2):27-37.

[3] Elmets, C. A. & Mukhtar, H. (1996) Prog. Dermatol. 30, 1–16.

[4] Brash DE, Rudolph JA, Simon JA, Lin A, McKenna GJ, Baden HP, Halperin AJ, Ponten J (1991) Proc Natl Acad Sci USA 88:10124–10128. 3.

[5] Ziegler A, Leffell DJ, Kunala S, Sharma HW, Gailani M, Simon JA, Halperin AJ, Baden HP, Shapiro PE, Bale AE, Brash DE (1993) Proc Natl Acad Sci USA 90:4216 – 4220. 4.

[6] Dumaz N, Drougard C, Sarasin A, Daya-Grosjean L (1993) Proc Natl Acad Sci USA90:10529 –10533.

[7] Tron VA, Li G, Ho V, Trotter MJ. Ultraviolet radiationinduced p53 responses in the epidermis are differentiation-dependent. J Cutan Med Surg. 1999 Jul;3(5):280-3.

[8] Halicka HD, Huang X, Traganos F, King MA, Dai W, Darzynkiewicz Z. Histone H2AX phosphorylation after cell irradiation with UV-B: relationship to cell cycle phase and induction of apoptosis. Cell Cycle. 2005 Feb;4(2):339-45.

[9] Zhao H, Traganos F, Darzynkiewicz Z. Kinetics of the UV-induced DNA damage response in relation to cell cycle phase. Correlation with DNA replication.

Cytometry A. 2010 Mar;77(3):285-93.

[10] Kastan MB, Onyekwere O, Sidransky D, Vogelstein B, Craig RW. Participation of p53 protein in the cellular response to DNA damage. Cancer Res. 1991 Dec 1;51(23 Pt 1):6304-11.

[11] Smith ML, Ford JM, Hollander MC, Bortnick RA, Amundson SA, Seo YR, Deng CX, Hanawalt PC, Fornace AJ Jr. p53-mediated DNA repair responses to UV radiation: studies of mouse cells lacking p53, p21,

[18]

[19]

[20]

[21]

and/or gadd45 genes. Mol CellBiol. 2000 May;20(10):3705-14.

Christmann M, Tomicic MT, Origer J, Aasland D, Kaina B. c-Fos is required for excision repair of UV-light induced DNA lesions by triggering the re-synthesis of XPF. Nucleic Acids Res. 2006;34(22):6530-9. Epub 2006 Nov 27.

Gasparro, F. P., Mitchnick, M. & Nash, J. F. (1998) Photochem. Photobiol. 68, 243–256.

Emanuele E, Altabas V, Altabas K, Berardesca E. Topical Application of Preparations Containing DNA Repair Enzymes Prevents Ultraviolet-Induced Telomere Shortening and c-FOS Proto-Oncogene Hyperexpression in Human Skin: An Experimental Pilot Study. J Drugs Dermatol. 2013 Sep 1;12(9):1017-21.

Berardesca E, Bertona M, Altabas K, Altabas V, Emanuele E. Reduced ultraviolet-induced DNA damage and apoptosis in human skin with topical application of a photolyase-containing DNA repair enzyme cream: clues to skin cancer prevention.Mol Med Rep. 2012 Feb;5(2):570-4.

Wittbrodt J, Shima A, Schartl M (2002) Medaka - a model organism from the far East. Nat Rev Genet3:53-64.

Reinhardt HC, Schumacher B. The p53 network: cellular and systemic DNA damage responses in aging and cancer.Trends Genet. 2012 Mar;28(3):128-36.

Mirzayans R, Andrais B, Scott A, Murray D. New insights into p53 signaling and cancer cell response to DNA damage: implications for cancer therapy. J Biomed Biotechnol. 2012;2012:170325.

Cazzalini O, Scovassi AI, Savio M, Stivala LA, Prosperi E. Multiple roles of the cell cycle inhibitor p21(CDKN1A) in the DNA damage response. Mutat Res. 2010 AprJun;704(1-3):12-20.

Leeman MF, Curran S, Murray GI. The structure, regulation, and function of human matrix metalloproteinase-13. Crit Rev Biochem Mol Biol.

2002;37(3):149-66.

Kuivanen TT, Jeskanen L, Kyllönen L, Impola U, Saarialho-Kere UK Transformation-specific matrix metalloproteinases, MMP-7 and MMP-13, are present in epithelial cells of keratoacanthomas. Mod Pathol.

2006 Sep;19(9):1203-12

Figures

nanoPT2015 Porto (Portugal)

| 97

Mário G. Silveirinha Instituto de Telecomunicações-University of Coimbra, Coimbra, Portugal

Taming light at the nanoscale with metamaterials

mario.silveirinha@co.it.pt

Structured materials with unusual electromagnetic properties have received much attention after some influential works demonstrated that by introducing a new length scale in conventional metals and dielectrics–by tailoring the microstructure– it is possible to radically modify the electromagnetic response.

In this talk, I will present an overview of our research work on electromagnetic metamaterials and plasmonics, and discuss the unusual potentials of media with near zero permittivity, materials with a chiral response, and materials with anomalous dispersion. In particular, I will explain how low loss plasmonic materials may offer the opportunity to have light localization in open bounded systems with infinitely long oscillation lifetimes and no radiation loss [1] [2] . Moreover, I will show how chiral light may be used to harness the sign of optical forces, forcing a material body to be pulled towards a direction opposite to the photon flow (optical tractor beam). Finally, time permitting, I will discuss how by controlling the topology of a metamaterial it is possible to engineer the material dispersion and create reverse rainbows [3]-[5]. It is envisioned that these materialsmay useful for the design of improved optical instruments insensitive to chromatic aberrations.

References [1] M. G. Silveirinha, “Trapping Light in Open Plasmonic Nanostructures”, Phys. Rev. A, 89,023813, 2014.

[2] M. G. Silveirinha, “Optical instabilities and spontaneous light emission by polarizable movingmatter”, Phys. Rev. X, 4, 031013, 2014.

[3] T. A. Morgado, J. S. Marcos, J. T. Costa, J. R. Costa, C. A. Fernandes, M. G. Silveirinha,“Reversed Rainbow with a Nonlocal Metamaterial”, Appl. Phys. Lett.,105, 264101 (2014).

[4] J. T. Costa, M. G. Silveirinha, “Achromatic Lens Based on a Nanowire Material with Anomalous Dispersion”, Optics Express, 20, 13915, 2012.

[5] M. G. Silveirinha, “Anomalous dispersion of light colors by a metamaterial prism”, Phys. Rev. Lett., 102, 193903, 2009

98 | n a n o P T 2 0 1 5 P o r t o ( P o r t u g a l )

A. Soto Beobide1, E. D. Vogl1, S.M. Iconomopoulou1, Deniz Korkmaz2, Özlem Türkarslan2,G.A. Voyiatzis1

Carbon Nanotube reinforced Textiles for Civil Protection Services

1

Foundation for Research & Technology-Hellas– Institute of Chemical Engineering Sciences (FORTH / ICE-HT) Rio-Patras, Greece 2 Kordsa Global R&D Center, Kocaeli, Turkey asoto@iceht.forth.gr

A research joint venture led by Foundation for Research & Technology-Hellas, partnered with KORDSA Global, is developing new processes and technologies to scale up the production of carbon nanotubes dispersed in polymers, to create textile fibers with enhanced performance and new functionality that cannot be provided by polymers or traditional composites.

Protective textiles are a field of intense research activity. Body armour materials have traditionally been designed to protect the wearer against any kind of weapon threats. Several new fibers and construction methods for bullet-proof fabrics have been developed besides woven Kevlar®, such as DSM’s Dyneema®, Honeywell’s Gold Flex® and Spectra®, Teijin Twaron’sTwaron® and Toyobo’s Zylon®. These high performance fibers are characterized by low density, high strength and high energy absorption. However, to meet the protection requirements for typical ballistic threats, several layers of fabric are required. It is also frequently to improve the body armour with stab resistant materials. The resulting bulk and stiffness of the armour limits the wearer’s mobility and agility. As a consequence, civil protection services are not used to wear the protection vest all the time, performing usual tasks such as patrolling or driving, since the models currently on the market are heavy, bulky & inflexible. There is an obvious need to develop flexible and lightweight protective body armour.

This gap can be filled by means of carbon based materials. Since Iijima’s report on carbon nanotubes (CNT) in 1991[1], scientists have been attracted by CNT’s unique atomic structure and properties.

Because of the combination of low density, nanometer scale diameters, high aspect ratio, and more importantly, unique physical properties such as extremely high mechanical strength and modulus, CNTs are ideal as potential reinforcing filler without

adding extra weight and contributing with excellent performance. The inclusion of CNTs in a polymeric matrix holds the potential to improve the host material’s mechanical properties by orders of magnitude well above the performance of traditional fillers. The challenges for developing high performance polymer/CNTs composites include the dispersion of CNTs in the polymeric matrix and interfacial interactions to ensure efficient load transfer from the polymeric matrix to the CNTs. The challenge of achieving efficient CNT dispersion and orientation within the polymer composite poses a substantial obstacle to the development of relevant beyond the state of the art fabrics. In other words, the mechanical properties of CNT composites fibers are highly dependent on CNT loading, dispersion and orientation, as well as pertinent to the polymer matrix characteristic properties. Substantial research efforts have been undertaken toward preparation (in the lab-scale) and characterization of polymer nanocomposites.

Experimental methods: The MWCNTs (NTX1) used in this work were purchased from NanoThinx S.A. (Greece). Carboxyl (-COOH) functionalized MWCNTs (NTX5) were also purchased by NanoThinx. Chemical oxidation was carried out by two pertinent treatments, one mild by utilizing nitric acid followed by hydrogen peroxide and a second one, a mixture of nitric/sulfuric acid, significantly more aggressive.

The polymer used in this work is poly(ethylene terephthalate), PET (iv ≥ 1 dL/g). Nanocomposites of 0.5, 1 and 2 wt% were prepared by melt mixing under nitrogen atmosphere in a homemade batch mixer. Polymer films were prepared by melt pressing a small part of the master batch at 285°C followed by quenching in ice water.

TGA in N2 atmosphere was conducted for all MWCNTs shown. In the thermograms shown in Figure 2, the most thermally stable material is the

nanoPT2015 Porto (Portugal)

| 99

as-received MWCNTs (NTX1), which does not lose weight after being heated to 600째C. This is due to the low content of amorphous carbon in the as received material. When a mild oxidation is conducted, the amount and rate of weight loss is very similar to that of the asreceived material, indicating that no or very few amorphous carbon has been generated because of the acid treatment.

The aggressive oxidation treatment, on the other hand, significantly degrades the graphitic structure of the MWCNTs by converting it to amorphous carbon, which is evident by the pronounced weight loss observed early in TGA curve.

References [1] Iijima S., Nature, 354 (1991) 56-58.

Figures

Figure 1: Scheme of CNT functionalization

The tensile stress-strain curves of pure PET and the examined PET/MWCNTs composites at 0.5, 1, 2 wt% loading are presented in Figure 3. The absence of significant improvements in the mechanical properties of the NTX5 composites may be the result of aggregation, as well as poor interfacial interaction between the NTX5 MWCNTs and PET. Quite different properties are obtained for the composites that CNTs were oxidized by mild and aggressive treatment. With respect to neat PET, these composites showed an increase in the strength and failure strain, although the improvement in elastic modulus may not be statistically significant. The large improvement in the tensile properties of these composites is attributed to the improved dispersion of MWCNTs inside the matrix and improved interactions between the MWCNTs and PET, mostly by hydrogen bonding, enhancing the interfacial bonding.

Fabrication of PET/CNTs for textile applications both on laboratory and industrial scale needs to be optimized in terms of processing conditions that include pre-mixing parameters, feeding rate, temperature of extrusion die and screw speed in order to get new carbon nanotubes based materials with enhanced properties. Carbon nanotubes-PET monofilaments prepared at industrial scale (based on laboratory scale efforts) will be characterized and optimized for the required textile application.

Figure 2: TGA curves of MWCNTs samples

Figure 3: Representative stress-strain curves for PET and PET nanocomposites of all concentrations.

Acknowledgements The research leading to these results was cofounded by the European Regional Development Fund (FP7/2007-2013) and Western Greece Region national resources under the grant agreement n째 235527 (LEADERA - Code: 2013-006 INPROTEX).

100 | n a n o P T 2 0 1 5 P o r t o ( P o r t u g a l )

M. Tarequzzaman, J. D. Costa, J. Borme, M. Gonzalez-Debs, B. Lacoste, E. Paz, S. Serrano-Guisan, R. Ferreira and P. Freitas INL-International Iberian Nanotechnology Laboratory, Braga, Portugal tareq.zaman@inl.int

Spin torque nano-oscillator (STNO) explore dynamic magnetic effects induced in the free layer of magnetoresistive devices induced by spin polarized currents. Soon after its discovery, STNO draw much attention to the researchers because of its advantages over conventional CMOS oscillators. The advantage of STNO covers, simple structure, smaller footprint (<200nm), high frequency tunability, large frequency (2-20 GHz range oscillations depending on magnetic field), low cost and good compatibility with the standard complementary metal oxide semiconductor (CMOS) technology [1-3]. However several challenges need to be addressed before STNOs are to be used in practical purpose. As it has critical disadvantages in terms of lower output power and relatively large linewidth in comparison with voltage controlled oscillators (VCOs) [4].

The power generation of STNO depends on several factors; resistance change induced by the magnetoresistance (MR) effect in the magnetization oscillations is one of them. Therefore, MgO based magnetic tunnel junctions (MTJs) with higher MR ratio (>50%) deliver larger microwave signals than metallic oscillators with lower MR ratio (<10%) [3].

In addition to this, another requirement for a large power emission is the excitation of large-amplitude oscillations. To this end, several configurations for the magnetization of the free and pinned layer have been proposed.

In this work, MTJ stacks (50 Ta/ X CoFe40B20/MgO 2 [3.0 Ohm-µm ]/2.2 CoFe40B20/0.85 Ru/2.0 CoFe30/20 IrMn (Thickness in nanometer) with an MgO barriers have been deposited using a Singulus TIMARIS PVD system. The free layer thickness (X) was changed between 2.0nm (free layer magnetization in plane) down to 1.0nm (free layer magnetization perpendicular to plane). These stacks were then patterned into nanopillars with different shapes (circular and elliptical) and dimension (50 nm to 200

Large power emission in MTJ based spin torque nano-oscillators using a free layer near the in-plane to out-of plane transition

nm in diameter) by electron beam lithography and ion milling technique.

The nano-pillars have been measured in a radio frequency transport measurement setup at room temperature. It is found that a large power output with a small linewidth is obtained in nano-pillars with a free layer thickness of 1.4nm which still have an in-plane magnetization but right at the transition to out-of-plane magnetization, i.e., the in-plane free layer experiences a very strong perpendicular anisotropy contribution.

An example of such measurements is shown in Fig. 1.a. for a pillar with circular shape and 150nm diameter. The result, show in Fig. 2, displays microwave signals with maximum power of 300 nW and narrow linewidth as small as 30 MHz. These STNOs operate with frequencies in the range between 2.4-2.8GHz .The large power output and narrow linewidth of these nano-oscillators make them good candidates for integration with CMOS circuits such as new generation Phase-Locked-Loops (PLLs).

References [1] Z. Zeng, G. Finocchio, B. Zhang, P. K. Amiri, J. A. Katine, I. N: Krivorotov, Y. Huai, J. Langer, B. Azzerboni, K. L. Wang, and H. Jiang, Sci. Rep. 3, (2013) 1426 [2] S. I. Kiselev, J. C. Sankey, I. N. Krivorotov, N. C. Emley, R. J. Schoelkopf, R. A. Burman, D. C. Ralph, Nature. 425, (2003), 380–383.

[3] Z. Zeng, P. K. Amiri, I. N. Krivorotov, H. Zhao, G. Finocchio, J.-P. Wang, J. A. Katine, Y. Huai, J. Langer, O. K Galatsis, K. L. Wang, and H. Jiang, ACS Nano 6, (2012) 6115–6121 [4] H. S. Choi, S. Y. Kang, S. J. Cho, I. Y. Oh, M. Shin, H. Park, C. Jang, B. C. Min, S.Kim, S.Y. Park, C. S. Park, Sci. Rep. 4,(2014) 5486

nanoPT2015 Porto (Portugal)

| 101

Figures

Figure1: a) Illustration of radio frequency (RF) measurement setup. b) The measured MTJ stack and nanopillar dimension.

Figure2: a) Transport measurement (two contact measurement) in easy and hard axis. The arrow indicating the RF measurement point b) Microwave emission spectra measured in positive bias currents (Black spectrum) and negative bias currents (Red Spectrum). c) Shows the results, in terms of power emissions, linewidth, frequency tunability and resistance.

102 | n a n o P T 2 0 1 5 P o r t o ( P o r t u g a l )

Ana Vila1, Clotilde Costa2, Carlos Rodríguez-Abreu1, Miguel Abal2, Rafael López-López2, José Rivas3 1 International Iberian Nanotechnology Laboratory (INL), Braga, Portugal 2 Translational Medical Oncology Group, Complejo Hospitalario Universitario de Santiago de Compostela, Santiago de Compostela, Spain 3 Department of Applied Physics; Nanotechnology and Magnetism Lab — NANOMAG, University of Santiago de Compostela, Santiago de Compostela, Spain

Designed Nanocomposite Magnetic Beads for isolation of Circulating Tumor Cells (CTC)

ana.vila@inl.int

In recent years, there has been an increasing interest in the isolation of Circulating Tumor Cells (CTC), which are metastasis cells circulating in peripheral blood of cancer patients, for prognostic, diagnostic and therapeutic applications. Magnetic separation is one of the methods of choice for cell isolation. For this purpose, submicrometer polymeric beads loaded with different content of magnetite nanoparticles (30-44 wt%) were prepared by mini-emulsion polymerization and characterized in terms of size, and magnetic properties. The beads were functionalized with a customized method with Protein A for incorporating antibodies and studying their interaction with EpCAM cancer cells.

Superparamagnetic and colloidally stable polymeric beads with size between 140 and 200 nm were obtained. Moreover, they were covalently covered by protein A and therefore enabled to be coupled with antibodies. After incubation of the polymeric beads with EpCAM cells, it was confirmed by flow cytometry that the beads were specifically and efficiently adsorbed on the cell´s surface and without aggregation of free beads. It was found that the magnetic isolation of labelled cells, became more efficient as the magnetite content increased up to 44 wt%.

Notably, the synthesized nanocomposite polymer beads were more efficient for cell isolation than micron-sized commercial beads, which much improves sample stability for handling and enables a larger specific contact area.

Figures

Figure 1: Bead Structure

Figure 2: SEM image of beads

Table 1: Bead Characteristics

Table 2: Cell Isolation Efficiency of beads

nanoPT2015 Porto (Portugal)

| 103

M.Vila1, M.C.Matesanz2, G.Gonçalves1, 2 2 M.J.Feito , J.Linares , P.A.A.P. 1 Marques ,M.T.PortolÊs2, M.Vallet-Regi3,4 1 TEMA-NRD, Mechanical Engineering Department and Aveiro Institute of Nanotechnology (AIN),University of Aveiro, Aveiro, Portugal 2 Department of Biochemistry and Molecular Biology I, Faculty of Chemistry, UCM, Madrid, Spain 3 Department of Inorganic and Bioinorganic Chemistry, Faculty of Pharmacy, UCM, Madrid, Spain 4 Networking Research Center on Bioengineering, Biomaterials and Nanomedicine, CIBER-BBN, Spain

Nanographene Oxide mediated cell hyperthermia

mvila@ua.pt

Graphene and more specifically, pegylated grapheme oxide (GO) has been proposed as a highly efficient in vivo photothermal therapy agent due to its strong Near- Infrared (NIR 700-1100 nm range) optical absorption ability. Its small two dimensional size could be unique performing when compared to any other nanoparticle, therefore, light should be given to the hyperthermia route and the kind of GO cell interactions induced in the process. The type of cell damage and toxicity produced by Near-infrared (NIR) laser irradiation has been evaluated as a function of exposure time and laser power in order to control the temperature rise and consequent

damage in the GOs containing tumoral cell culture medium. The results showed that cell culture temperature (after irradiating cells with internali zed GO) increases preferentially with laser power rather than with exposure time. Moreover, when laser power is increased, necrosis is the preferential cell death leading to an increase of cytokine release to the medium. The results suggested that tailoring cell death, the threshold for producing thermal ablation with soft or harmful damage could be specifically controlled and so, the immune response.

104 | n a n o P T 2 0 1 5 P o r t o ( P o r t u g a l )

X. G. Wang, Y. ko‘lenko, Lifeng Liu International Iberian Nanotechnology Laboratory (INL), Braga, Portugal lifeng.liu@inl.int

Hydrogen is a future energy carrier for both stationary and motive power generation. Water splitting offers a clean and sustainable way to produce hydrogen, as water is an almost inexhaustible renewable source and the water splitting process is not as energy-intensive as steam reforming. However, in order to achieve a high water splitting efficiency, an electrocatalyst for the hydrogen evolution reaction (HER) is crucially needed to render a high current at low overpotentials.

Platinum (Pt) has so far been the most efficient and commonly used electrocatalysts for HER. But it is not practical and economically viable to use Pt for largescale application because of its high cost and scarcity.

Therefore, developing earth-abundant and low cost HER catalysts having comparable activity and stability as Pt is highly desired [1]. Very recently, transition metal phosphides (TMPs), such as Ni2P, CoP, MoP, FeP, etc., have emerged as a new class of catalysts which show sufficiently high electrocatalytic activity and excellent stability toward HER in acidic electrolytes [2,3].

In this work, we report a facile route to the growth of nickel phosphide (Ni2P) nanoneedles on commercially available nickel (Ni) foam, which involves direct phosphorization of Ni foam under solvethermal conditions using red phosphorous as a precursor [4]. This results in the formation of welldefined Ni2P nanoneedles on the entire surface of the Ni foam (see Figure 1a). The electrocatalyic performance of the as-fabricated Ni2P/Ni electrode was evaluated by linear scan voltammetry (LSV) and electrochemical impedance spectroscopy (EIS) in 0.5 -2 M H2SO4. A cathodic current as high as 42 mA cm was observed at an overpotential of 200 mV, and to -2 afford a current density of 20 mA cm only a small overpotential of 162 mV is needed (see Figure 1b).

The EIS result reveals that the charge transfer resistance of the Ni2P nanoneedles is 143.2 Ω, close to that of the Pt foil (104.4 Ω). Moreover, the Ni2P/Ni also exhibits reasonably good stability due to the protection of a continuous Ni12P5 layer

Direct Growth of Nickel Phosphoride Nanoneedles on Nickel Foam for Efficient Electrocatalytic Hydrogen Evolution underneath the nanoneedles. The observed good electrocatalytic performance of the Ni2P/Ni can be attributed to the unique 3D porous feature of the Ni foam, which is not only beneficial for the mass transfer of the electrolyte and release of H2 gas bubbles, but also greatly facilitates the electron transport in the overall electrode. The Ni2P nanoneedles supported on Ni foam reported in this work hold substantial promise for use as efficient and low-cost cathodes in electrolyzers.

References [1] Morales-Guio, C. G., Stern, L. A., Hu, X. L. Nanostructured hydrotreating catalysts for electrochemical hydrogen evolution, Chem. Soc. Rev. 43 (2014) 6555-6569.

[2] Popczun, E. J., McKone, J. R., Read, C. G., Biacchi, A. J., Wiltrout, A. M., Lewis, N. S., Schaak, R. E. Nanostructured nickel phosphide as an electrocatalyst for the hydrogen evolution reaction, J. Am. Chem. Soc. 135 (2013) 92679270.

[3] Liu, Q., Tian, J. Q., Cui, W., Jiang, P., Cheng, N. Y., Asiri, A. M., Sun, X. P. Carbon nanotubes decorated with CoP nanocrystals: A highly active non-noble-metal nanohybrid electrocatalyst for hydrogen evolution, Angew.

Chem. Int. Ed. 126 (2014) 6828-6832.

[4] Wang, X.G., Ko’lenko, Y., Liu, L.F. Direct growth of nickel phosphide nanoneedles on nickel foam for efficient electrocatalytic hydrogen evolution, under preparation

nanoPT2015 Porto (Portugal)

| 105

Figures

Figure 1: (a) A representative SEM image showing the nickel phosphide nanoneedle arrays grown on the ligament of the nickel foam and (b) comparison of the polarization curve of NiP/Ni with that of the Ni foam and Pt foil recorded in 0.5 M H2SO4 at a scan -1 rate of 10 mV s .

106 | n a n o P T 2 0 1 5 P o r t o ( P o r t u g a l )

New Quantum Physics Phenomena in Optical and Radio Spectroscopies

Dmitri Yerchuck Heat-Mass Transfer Institute of National Academy of Sciences of RB, Brovka Str.15, Minsk, 220072, Belarus

Brief review of the discoveries of new quantum physics phenomena in optical spectroscopy and radiospectroscopy is presented. They are the following 1. The phenomenon of ferroelectric spin wave resonance, on which was reported for the first time in 2008, represents itself the optical analogue of ferromagnetic spin wave resonance.

2. It is especially interesting, that the detailed study of the phenomenon of ferroelectric spin wave resonance in quasi-1D carbon-based materials carbynoids - has led to the discovery of dually charged quasiparticles, possessing by both electric and magnetic charge components. It has been found, that the experimental value of the ratio of imagine (magnetic) to real (electric) complex charge components of dually charged quasiparticles is in the range of predictions of the theory, developed by Dirac for pointlike particles.

3.The phenomenon of antiferroelectric spin wave resonance, on the discovery of which was reported for the first time in 2009, is also the optical analogue of the corresponding magnetic phenomenon antiferromagnetic spin wave resonance.

consequence of strong electron-photon coupling, and it leads to the appearance of additional lines in stationary optical spectra, corresponding to Fourier transform of the revival part of the time dependence of integral inversion of coupled qubits.

It was reported in 2012.

6. The phenomenon of ferrimagnetic spin-wave resonance [uncompensated antiferromagnetic spinwave resonance] has been detected and reported for the first time quite recently, in 2014.

7. Peculiarities of ferrimagnetic spin-wave resonance allowed to insist on the formation in nanotubes incorporated in diamond single crystals in [100] + direction of s -superconductivity at room temperature, coexisting with uncompensated antiferromagnetic ordering, that is, the new kind of superconductivity mechanism, realizing in magnetic resonance conditions, was identified.

The discovered phenomena seem to be substantial for the applications in nanotechnology, for instance, for quantum informatics, quantum computing and for the elaboration of various quantum devices, especially realized on carbon nanonotubes aforeindicated or carbynoids, which are found being to be multiferroic materials.

4. The existence of own electric spin moment, that is, electric analogue of own magnetic spin moment, mathematically predicted by Dirac, by which can possess some quasiparticles in condensed matter, was confirmed for the first time. It is the result of detailed study of the phenomenon of antiferroelectric spin wave resonance in carbynoids.

5. A new quantum optics phenomenon â&#x20AC;&#x201C; the quantum Rabi oscillations' formation and propagation in space, predicted theoretically by Slepyan, Yerchak, Hoffmann, Bass, - has experimentally been identified for the first time in carbon nanotubes, incorporated in diamond single crystals, in carbynoid films, and in graphene. It is the

nanoPT2015 Porto (Portugal)

| 107

Late abstract

InĂŞs M. Pinto International Iberian Nanotechnology Laboratory, Braga, Portugal ines.m.pinto@inl.int

Epithelial Tumor Dynamics: Nanocharacterization of force-generating structures

The International Iberian Nanotechnology Laboratory (INL) is an international organization created to foster interdisciplinary research in Nanotechnology and Nanosciences. The main goal of the Laboratory is to undertake ground-breaking scientific research in specific areas such as nanomedicine.

At NanoPT2015, we present one of our projects aiming the development of biomechanical-based markers for early diagnosis of epithelial tumors, by combining tools and concepts from different fields: quantitative cell imaging analysis, genetic engineering, nanoscale reconstituted systems and biophysical modelling. The innovative nature of this project will likely impact the development of selective anticancer drugs and novel methods for therapy control.

108 | n a n o P T 2 0 1 5 P o r t o ( P o r t u g a l )

P o ste r s L ist

WĞĚƌŽ ĂƉƚŝƐƚĂ͕ :ŽĆŽ >ŝŵĂ

ŽƌĚĞŝƌŽ͕ DşůƚŽŶ

/ǀĂŶĂ :ĂƌĂŬ͕ ZƵŝ ^ŝůǀĂ͕ ŶƚſŶŝŽ ^͘ ĂƌƌŽƐ͕ ŶĂ D͘ 'ŝů͕D͘ >ŽƵƌĚĞƐ WĞƌĞŝƌĂ͕ D͘ >ƵŝƐĂ ŽƌǀŽ͕ /ŽůĂ &͘ ƵĂƌƚĞ

ĂƌƌŽůĂ͕ :ŽĂŶĂ

,ĞŶƌŝŬ ,ĂƐƉĞů͕ ŬŽƐ <ƵŬŽǀĞĐnj͕ ŽůƚĄŶ <ſŶLJĂ

ƵĐŚŚŽůĐnj͕ ĂůĄnjƐ

͘ ,ĂĚƌŝ͕ >͘ dŽƌƌŝƐŝ͕ ^͘ WĂƚĂŶğ͕ ͘ ĂĚĚĞŵŝ Θ '͘ ƌƵƉŝ

ŽƵŬŽƌƚƚ͕ EŽƵƌ ů /ƐůĂŵ

:ĂǀŝĞƌ ĂůǀŽ͕ ŶƌŝƋƵĞ Ăƌďſ ƌŐŝďĂLJ͕ ƌĞĂ ŽƌƌĂũŽ ůŽŶƐŽ͕ &ĞƌŶĂŶĚŽ ŽŵşŶŐƵĞnj͕ D͘ ƌƚƵƌŽ >ſƉĞnj YƵŝŶƚĞůĂ ĂŶĚ :ŽƐĠ ZŝǀĂƐ

ůĂŶĐŽ͕ :ŽƐĞ DĂŶƵĞů

DŝĐŚĂĞů ĞůǀĞƐ͕ hƌƐƵůĂ ^ƚƌĂƐĐŚŝů͕ ůŝƐĂďĞƚ DĂƌƚş͕ ůŝƐĂďĞƚƚĂ ZĂŶƵĐĐŝ͕ WĂŽůŽ &ĞƌƌƵƚŝ͕ ZŽďĞƌƚ ^ŝŶĚĞŶ͕ yĂǀŝĞƌ &ĞƌŶăŶĚĞnjͲ ƵƐƋƵĞƚƐ

njĞǀĞĚŽ ^ŝůǀĂ DĂƌƋƵĞƐ͕ :ŽĂŶĂ

EĞǀĞƐ͕ ͘ Z͕͘ 'ŽƵǀĞŝĂ͕ s͕͘ DŽƵƌĂ͕ ͕͘ EƵŶĞƐ͕ ͘ ĂŶĚ ZĞŝƐ͕ ^

ƌĂƷũŽ͕ :ŽƐĠ

ĂƚĂƌŝŶĂ ŽƐƚĂ DŽƵƌĂ͕ ƌƵŶŽ ^ĂƌŵĞŶƚŽ͕ ^ĂůĞƚƚĞ ZĞŝƐ

ůďƵƋƵĞƌƋƵĞ͕ :ŽĆŽ

ŚŵĂĚ͕ DŽŚĂŵĂĚ

ĂƵƚŚŽƌƐ

KŶůLJ WŽƐƚĞƌƐ ƐƵďŵŝƚƚĞĚ ďLJ ƌĞŐŝƐƚĞƌĞĚ ƉĂƌƚŝĐŝƉĂŶƚƐ ĂƌĞ ůŝƐƚĞĚ ďĞůŽǁ ;ϯϬͬϬϭͬϮϬϭϱͿ

WŽƌƚƵŐĂů

WŽƌƚƵŐĂů

,ƵŶŐĂƌLJ

/ƚĂůLJ

WŽƌƚƵŐĂů

^ƉĂŝŶ

WŽƌƚƵŐĂů

WŽƌƚƵŐĂů

^ĂƵĚŝ ƌĂďŝĂ

ĐŽƵŶƚƌLJ

EĂŶŽďŝŽͬEĂŶŽDĞĚŝĐŝŶĞ

EĂŶŽďŝŽͬEĂŶŽDĞĚŝĐŝŶĞ

EĂŶŽŵĂƚĞƌŝĂůƐ

DŽĚĞůŝŶŐ Ăƚ ƚŚĞ ŶĂŶŽƐĐĂůĞ

EĂŶŽŵĂƚĞƌŝĂůƐ

EĂŶŽďŝŽͬEĂŶŽDĞĚŝĐŝŶĞ

EĂŶŽďŝŽͬEĂŶŽDĞĚŝĐŝŶĞ

EĂŶŽďŝŽͬEĂŶŽDĞĚŝĐŝŶĞ

KƚŚĞƌ

ƚŽƉŝĐ

ƉŽƐƚĞƌ ƚŝƚůĞ

͞&Z d ďĂƐĞĚ ŐŽůĚ ŶĂŶŽďĞĂĐŽŶ ĨŽƌ ƐĞƋƵĞŶĐĞ ĚŝƐĐƌŝŵŝŶƚĂƚŝŽŶ͟

͞DĞƚĂďŽůŝĐ ĞĨĨĞĐƚƐ ŽĨ ƐŝůǀĞƌ ŶĂŶŽƉĂƌƚŝĐůĞƐ ĂƐƐĞƐƐĞĚ ďLJ EDZ ŵĞƚĂďŽůŽŵŝĐƐ ŽĨ ŵŝĐĞ ůŝǀĞƌ ĂŶĚ ƐĞƌƵŵ͟

͞>ŽǁͲƚĞŵƉĞƌĂƚƵƌĞ ĐŽŶǀĞƌƐŝŽŶ ŽĨ ƚŝƚĂŶĂƚĞ ŶĂŶŽƚƵďĞƐ ŝŶƚŽ ŶŝƚƌŽŐĞŶͲĚŽƉĞĚ dŝKϮ ŶĂŶŽƉĂƌƚŝĐůĞƐ͟

͞tŽƌŬ &ƵŶĐƚŝŽŶ ĂŶĚ 'ĂƚĞ >ĞŶŐƚŚ ĨĨĞĐƚ KŶ ůĞĐƚƌŝĐĂů ŚĂƌĂĐƚĞƌŝƐƚŝĐƐ KĨ ŶͲ&ŝŶ& d ŝŶ ϯ hƐŝŶŐ d> ^ ^/>s K͟

͞tĂƚĞƌͲ ŝƐƉĞƌƐŝďůĞ ^ŝůǀĞƌ EĂŶŽĐůƵƐƚĞƌƐ͗ ^LJŶƚŚĞƐŝƐ ĂŶĚ ŚĂƌĂĐƚĞƌŝnjĂƚŝŽŶ͟

͞dĂƌŐĞƚŝŶŐ ŽĨ WůĂƐŵŽĚŝƵŵ ƚƌĂŶƐŵŝƐƐŝŽŶ ƐƚĂŐĞƐ ǁŝƚŚ ƉŽůLJŵĞƌƐ Ͳ &/d ĨŽƌ ĨƵƚƵƌĞ ĂŶƚŝŵĂůĂƌŝĂů ĚĞůŝǀĞƌLJ ƐƚƌĂƚĞŐŝĞƐ͟

͞^ƵƌƉĂƐƐŝŶŐ E^ / Ɛ ƐŝĚĞͲĞĨĨĞĐƚƐ ǁŝƚŚ >ŝƉŝĚ EĂŶŽƉĂƌƚŝĐůĞƐ͟

͞&ƵŶĐƚŝŽŶĂůŝnjĞĚ ^ŽůŝĚ >ŝƉŝĚ EĂŶŽƉĂƌƚŝĐůĞƐ͗ Ă ƚŚĞƌĂŶŽƐƚŝĐ ĂƉƉƌŽĂĐŚ ĨŽƌ ƚŚĞ ƚƌĞĂƚŵĞŶƚ ŽĨ ZŚĞƵŵĂƚŽŝĚ ƌƚŚƌŝƚŝƐ͟

͞DĞĐŚĂŶŽƐLJŶƚŚĞƐŝƐ ĂŶĚ ^ƉĂƌŬ WůĂƐŵĂ ^ŝŶƚĞƌŝŶŐ ŽĨ &ŝŶĞͲ'ƌĂŝŶĞĚ EĂϭͬϮ ŝϭͬϮ ƵϯdŝϰKϭϮ ĞƌĂŵŝĐƐ ǁŝƚŚ 'ŝĂŶƚ ŝĞůĞĐƚƌŝĐ ZĞƐƉŽŶƐĞ͟

WŽƐƚĞƌƐ ůŝƐƚ ĂůƉŚĂďĞƚŝĐĂů ŽƌĚĞƌ

ƌŝƐƚŝŶĞ 'ŽŶĕĂůǀĞƐ ͕ ƵĂƌƚĞ DĞůŽͲ ŝŽŐŽ͕ ůŝƐĂďĞƚĞ ͘ ŽƐƚĂ͕ :ŽĆŽ ͘ YƵĞŝƌŽnj͕ ŚĂŶƚĂů WŝĐŚŽŶ͕ &ĂŶŝ ^ŽƵƐĂ ĂŶĚ /ůşĚŝŽ :͘ ŽƌƌĞŝĂ

'ĂƐƉĂƌ͕ sŝƚŽƌ

KƌĨĞƵ &ůŽƌĞƐ͕ 'ŽŶĕĂůŽ ŽƌŝĂ͕ WĞĚƌŽ sŝĂŶĂ ĂƉƚŝƐƚĂ

&ĞƌƌĞŝƌĂ ĂƌůŽƐ͕ &ĄďŝŽ

:ŽƌŐĞ &͘ WĞĚƌŽƐĂ͕ dŝĂŐŽ &͘ EƵŶĞƐ͕ ŶĂ &͘ >ŽƵƌĞŶĕŽ͕ :ŽƐĠ ͘ 'ĂŵĞůĂƐ

&ĞƌƌĞŝƌĂ͕ WĂƵůŽ

^ŽĨŝĂ ͘ ŽƐƚĂ >ŝŵĂ͕ ^ĂůĞƚƚĞ ZĞŝƐ

&ĞƌƌĞŝƌĂ͕ DĂƌĂ

:͘ ͘ &ĞƌƌĞƌ͕ : ͘>͘ ůŽŶƐŽ ĂŶĚ ͘ ZĂŬŬĂĂ

&ĞƌŶĂŶĚĞnj ĚĞ ǀŝůĂ͕ ^ƵƐĂŶĂ

:͘ ͘ &ĞƌƌĞƌ͕ : ͘>͘ ůŽŶƐŽ

&ĞƌŶĂŶĚĞnj ĚĞ ǀŝůĂ͕ ^ƵƐĂŶĂ

DĂƌşĂ ŽŶĐĞƉĐŝſŶ ^ĞƌƌĂŶŽ͕ ůǀĂƌŽ ůĂŶĐŽ͕ ĞĨĞ >ſƉĞnj

ƐƉŝŶŚĂ͕ ŶĚƌĠ

D͘ ŽŶĐĞŝĕĆŽ WĂŝǀĂ͕ D͘ &ĞƌŶĂŶĚĂ WƌŽĞŶĕĂ͕ ZƵŝ ƌĂƷũŽ

ƵŶŚĂ͕ ƵŶŝĐĞ

:͘K͘ ĂƌŶĞŝƌŽ͕ ͘ W͘ ^ĂŵĂŶƚŝůůĞŬĞ͕ W͘ WĂƌƚƉŽƚ͕ dĂǀĂƌĞƐ͕ &͘ &ĞƌŶĂŶĚĞƐ͕ D͘ WĂƐƚŽƌ͕ ͘ ŽƌƌĞŝĂ͕ s͘ dĞŝdžĞŝƌĂ

ŽƐƚĂ͕ DĂŶƵĞů &ŝůŝƉĞ

͘ WĂnj͕ :͘ ŽƌŵĞ͕ ^͘ ^ĞƌƌĂŶŽ͕ :͘D͘ dĞŝdžĞŝƌĂ͕ :͘ sĞŶƚƵƌĂ͕ Z͘ &ĞƌƌĞŝƌĂ͕ W͘ W͘ &ƌĞŝƚĂƐ

ŽƐƚĂ͕ :ŽƐĠ ŝŽŐŽ

͘ DĂůĂŵĂŶ ĂŶĚ '͘ >Ğ Ăģƌ

ŽƐƚĂ͕ ĞŶŝůĚĞ

ĂƵƚŚŽƌƐ

WŽƌƚƵŐĂů

WŽƌƚƵŐĂů

WŽƌƚƵŐĂů

WŽƌƚƵŐĂů

^ƉĂŝŶ

^ƉĂŝŶ

^ƉĂŝŶ

WŽƌƚƵŐĂů

WŽƌƚƵŐĂů

WŽƌƚƵŐĂů

WŽƌƚƵŐĂů

ĐŽƵŶƚƌLJ

EĂŶŽďŝŽͬEĂŶŽDĞĚŝĐŝŶĞ

EĂŶŽďŝŽͬEĂŶŽDĞĚŝĐŝŶĞ

EĂŶŽŵĂƚĞƌŝĂůƐ

EĂŶŽďŝŽͬEĂŶŽDĞĚŝĐŝŶĞ

EĂŶŽŵĂƚĞƌŝĂůƐ

EĂŶŽŵĂƚĞƌŝĂůƐ

KƉƚŝĐƐͬWŚŽƚŽŶŝĐƐͬWůĂƐŵŽŶŝĐƐ

'ƌĂƉŚĞŶĞͬEĂŶŽƚƵďĞƐ

EĂŶŽŵĂƚĞƌŝĂůƐ

EĂŶŽŵĂƚĞƌŝĂůƐ

EĂŶŽŵĂƚĞƌŝĂůƐ

ƚŽƉŝĐ

ƉŽƐƚĞƌ ƚŝƚůĞ

͞^ŝŵƵůƚĂŶĞŽƵƐ ĞůŝǀĞƌLJ ŽĨ ƌƵŐƐ ĂŶĚ 'ĞŶĞƐ ďLJ DƵůƚŝͲ ůŽĐŬ WŽůLJŵĞƌŝĐ EĂŶŽŵŝĐĞůůĞƐ ĨŽƌ ^LJŶĞƌŐŝƐƚŝĐ ĂŶĐĞƌ dŚĞƌĂƉLJ͟

͞ ŚĂƌĂĐƚĞƌŝnjĂƚŝŽŶ ŽĨ ŐĞŶŽŵŝĐ ^EW ǀŝĂ ĐŽůŽƌŝŵĞƚƌŝĐ ĚĞƚĞĐƚŝŽŶ ƵƐŝŶŐ Ă ƐŝŶŐůĞ ŐŽůĚ ŶĂŶŽƉƌŽďĞ͟

͞ ĞůůƵůŽƐĞ ŶĂŶŽĨŝďƌĞƐ ŽďƚĂŝŶĞĚ ďLJ d DWK ŵĞĚŝĂƚĞĚ ŽdžŝĚĂƚŝŽŶ ĂŶĚ ŵĞĐŚĂŶŝĐĂů ƚƌĞĂƚŵĞŶƚ͗ ĞĨĨĞĐƚ ŽĨ ƚŚĞ ŵĞĐŚĂŶŝĐĂů ƚƌĞĂƚŵĞŶƚ͟

͞KƉƚŝŵŝnjĂƚŝŽŶ ĂŶĚ ĐŚĂƌĂĐƚĞƌŝnjĂƚŝŽŶ ŽĨ ůŝƉŝĚͲďĂƐĞĚ ŶĂŶŽƉĂƌƚŝĐůĞƐ ĨŽƌ ƚŽƉŝĐĂů ƚŚĞƌĂƉLJ ŽĨ ƉƐŽƌŝĂƐŝƐ͟

͞DŽĚŝĨŝĐĂƚŝŽŶ ŽĨ ŽƉƚŝĐĂů ƉƌŽƉĞƌƚŝĞƐ ŽĨ ƉŽůLJŵĞƌ ĨŝůŵƐ ďLJ ĂĚĚŝƚŝŽŶ ŽĨ Wď^ ŶĂŶŽƉĂƌƚŝĐůĞƐ͟

͞^LJŶƚŚĞƐŝƐ ĂŶĚ ŽƉƚŝĐĂůƉƌŽƉĞƌƚŝĞƐ ŽĨ Ě^Ğ ŶĂŶŽƉĂƌƚŝĐůĞƐ ŝŶ Ws< ƐĞŵŝĐŽŶĚƵĐƚŝŶŐ ƉŽůLJŵĞƌ͟

͞EĂŶŽĐŽŵƉŽƐŝƚĞ ŵĂƚĞƌŝĂůƐ ĨŽƌ ƐŚĂƉŝŶŐ ƚŚĞ ĚŝĨĨƵƐŝǀĞ ƚƌĂŶƐƉŽƌƚ ŽĨ ůŝŐŚƚ͟

͞ džĨŽůŝĂƚŝŽŶ ŽĨ ŐƌĂƉŚŝƚĞ ƵƐŝŶŐ ƉLJƌĞŶĞ ĂŶĚ ƉĞƌLJůĞŶĞ ĚĞƌŝǀĂƚŝǀĞƐ͟

͞dŚĞ ƌŽůĞ ŽĨ dŝKϮ ŶĂŶŽƉĂƌƚŝĐůĞƐ ĂŶĚ ƉŚŽƚŽĐĂƚĂůLJƚŝĐ ƉƌŽĐĞƐƐĞƐ ŝŶ ƚŚĞ ƚƌĞĂƚŵĞŶƚ ŽĨ ŝŶĚƵƐƚƌŝĂů ĞĨĨůƵĞŶƚƐ͟

͞EĂŶŽĨĂďƌŝĐĂƚŝŽŶ ŽĨ DĂŐŶĞƚŝĐ dƵŶŶĞů :ƵŶĐƚŝŽŶ WŝůůĂƌƐ dĂƌŐĞƚŝŶŐ EĂŶŽͲKƐĐŝůůĂƚŽƌ ƉƉůŝĐĂƚŝŽŶƐ͟

͞DĞĐŚĂŶŽƐLJŶƚŚĞƐŝƐ ŽĨ ƐƵƉĞƌƐĂƚƵƌĂƚĞĚ ƚĞƌŶĂƌLJ ƐŽůŝĚ ƐŽůƵƚŝŽŶƐ ;&Ğ ŽͿϭϬϬͲdž ^Ŷdž ĂŶĚ ƚŚĞŝƌ ŽƌĚĞƌŝŶŐ ďLJ ĂŶŶĞĂůŝŶŐ Ăƚ ůŽǁ ƚĞŵƉĞƌĂƚƵƌĞ͟

Z͘ ƌƌĂďĂů͕ D͘ DŽŚĞĚĂŶ͕ ͘ WĂƌĚŽ͕ ͘ DĂƚLJŬŝŶ͕ D͘ DĞƌŝŶŽ

DŝŶŐŽ ZŽŵĄŶ͕ ĞĂƚƌŝnj

s͘ ^ŝůǀĂ /͘ ZŽĚƌŝŐƵĞƐ͕ D͘ ͘ sŝĞŝƌĂ͕ D͘ sŝĞŝƌĂ

>ŽƵƌŽ ŶƚƵŶĞƐ͕ WĂƵůĂ

ZŝĞ &ƵŬĂĚĂ͕ ^ŚŽŬŽ ŵĂŶŽ

<ƵŐŝŵŝLJĂ͕ ŬŝŵŝƚƐƵ

D͘ 'ƌŽďĞůŶLJ͕ D͘ DĂnjƵƌ͕ ͘ tŽũĐŝĞƐnjĂŬ Θ ͘ <ĂĐnjŵĂƌĞŬ

<ĂůŝƐnj͕ DĂůŐŽƌnjĂƚĂ

d͘ zĂŵĂĚĂ͕ z͘ <ĂƚŽƵ͕ D͘ ŵĞLJĂ͕ D͘ ,ŽƌŝďĞ͕ d͘ EĂŬĂŵƵƌĂ͕ ,͘ EĂŶũŽ͕ d͘ ďŝŶĂ͕ D͘ ,ĂƐĞŐĂǁĂ

/ƐŚŝŚĂƌĂ͕ DĂƐĂƚŽƵ

Dŝnjŝ &ĂŶ ĂŶĚ ŚĂŽŚƵŝ ,ƵĂŶŐ

/ůLJĂƐ͕ DƵŚĂŵŵĂĚ

ĄƌďĂƌĂ ƌŐŝďĂLJ͕ zƵƌLJ s͘ <ŽůĞŶ͛ŬŽ͕ ŶƌŝƋƵĞ ĂƌďſͲ ƌŐŝďĂLJ͕ ZĂŵſŶ /ŐůĞƐŝĂƐ͕ &ƌĂŶĐŝƐĐŽ ĂŵƉŽƐ͕ >ĂƵƌĂ D͘ ^ĂůŽŶĞŶ͕ DĂŶƵĞů ĂŹŽďƌĞͲ>ſƉĞnj͕ :ŽƐĠ ĂƐƚŝůůŽ͕ :ŽƐĠ ZŝǀĂƐ

'ƵůĚƌŝƐ͕ EŽĞůŝĂ

^ſŶŝĂ 'ŽŶĕĂůǀĞƐ͕ EƵŶŽ ͘ ^ĂŶƚŽƐ͕ /ǀŽ ͘ DĂƌƚŝŶƐ

'ƵĞƌƌĂ͕ 'ĂďƌŝĞůĂ

DĂųŐŽƌnjĂƚĂ <ĂůŝƐnj

'ƌŽďĞůŶLJ͕ DĂƌĐŝŶ

ƵůĄůŝĂ WĞƌĞŝƌĂ͕ EƵŶŽ ͘ ^ĂŶƚŽƐ͕ DĂƌŝĂ D͘ DŽƚĂ͕ DŝŐƵĞů WƌƵĚġŶĐŝŽ͕ ZŝĐĂƌĚŽ &ƌĂŶĐŽ

'ŽŵĞƐ͕ /ŶġƐ

/ŚŽƌ WĂǀůŽǀ͕ ^Ğƌŝŵ /ůĚĂLJ͕ ůďĞƌƚŽ ZŽƚĂ͕ DĂƐƐŝŵŽ DĞƐƐŽƌŝ͕ ^ĞLJĚŝ zĂǀĂƐ͕ >ĞŽŶĂƌĚŽ KƌĂnjŝ ĂŶĚ &͘ PŵĞƌ /ůĚĂLJ

'ŶŝůŝƚƐŬLJŝ͕ /ĂƌŽƐůĂǀ

ĂƵƚŚŽƌƐ

^ƉĂŝŶ

WŽƌƚƵŐĂů

:ĂƉĂŶ

WŽůĂŶĚ

:ĂƉĂŶ

h<

WŽƌƚƵŐĂů

WŽƌƚƵŐĂů

WŽůĂŶĚ

WŽƌƚƵŐĂů

/ƚĂůLJ

ĐŽƵŶƚƌLJ

EĂŶŽŵĂƚĞƌŝĂůƐ

KƉƚŝĐƐͬWŚŽƚŽŶŝĐƐͬWůĂƐŵŽŶŝĐƐ

KƚŚĞƌ

EĂŶŽŵĂƚĞƌŝĂůƐ

'ƌĂƉŚĞŶĞͬEĂŶŽƚƵďĞƐ

EĂŶŽŵĂƚĞƌŝĂůƐ

EĂŶŽďŝŽͬEĂŶŽDĞĚŝĐŝŶĞ

EĂŶŽŵĂƚĞƌŝĂůƐ

EĂŶŽŵĂƚĞƌŝĂůƐ

EĂŶŽďŝŽͬEĂŶŽDĞĚŝĐŝŶĞ

KƉƚŝĐƐͬWŚŽƚŽŶŝĐƐͬWůĂƐŵŽŶŝĐƐ

ƚŽƉŝĐ

͞^ƵƌĨĂĐĞ ŵŽƌƉŚŽůŽŐLJ ĂŶĚ ĐŽƌƌŽƐŝŽŶ ŝŶǀĞƐƚŝŐĂƚŝŽŶ ŽĨ ϵϭZ ŵĂŐŶĞƐŝƵŵ ĂůůŽLJ͟

͞dƌĂŶƐŵŝƐƐŝŽŶ ŽĨ ƐŝŐŶĂůƐ ƵƐŝŶŐ ǁŚŝƚĞ ĂŶĚ ǀŝƐŝďůĞ > Ɛ ĨŽƌ s> ĂƉƉůŝĐĂƚŝŽŶƐ͟

͞'ůLJĐŝŶĞ ĂŶĚ ůLJƐŝŶĞ ĂƐƐĂLJƐ ǁŝƚŚ ĞŶnjLJŵĂƚŝĐ ƌĞĂĐƚŝŽŶƐ ĂŶĚ ĞdžĂŵŝŶĂƚŝŽŶ ŽĨ ĚĞƚĞĐƚŝŽŶ ĐŽŶĚŝƚŝŽŶƐ͟

͞DĞĐŚĂŶŝĐĂů ĂŶĚ ĞůĞĐƚƌŽĐŚĞŵŝĐĂů ƉƌŽƉĞƌƚŝĞƐ ŽĨ ŶŝŽďŝƵŵ ŽdžŝĚĞ ůĂLJĞƌƐ ĚĞƉŽƐŝƚĞĚ ŽŶ dŝ ĂůůŽLJƐ ďLJ ƌĞĂĐƚŝǀĞ ŵĂŐŶĞƚƌŽŶ ƐƉƵƚƚĞƌŝŶŐ ƉƌŽĐĞƐƐ͟

͞>ĂƌŐĞͲƐĐĂůĞ ŐƌĂƉŚĞŶĞ Ĩŝůŵ ƐLJŶƚŚĞƐŝnjĞĚ ďLJ ƉůĂƐŵĂ ƚƌĞĂƚŵĞŶƚ ŽĨ Ƶ ĨŽŝů ĂŶĚ ŝƚƐ ĞůĞĐƚƌŽŵĂŐŶĞƚŝĐ ƐŚŝĞůĚŝŶŐ ƉƌŽƉĞƌƚLJ͟

͞hƐĞ ŽĨ EĂŶŽͲdĞĐŚŶŽůŽŐLJ ĂŶĚ EĂŶŽŵĂƚĞƌŝĂů ŝŶ ƚŚĞ ĞǀĞůŽƉŵĞŶƚ ŽĨ EĂŶŽĐŽŵƉŽƐŝƚĞ ĞŵĞŶƚŝƚŝŽƵƐ DĂƚĞƌŝĂůƐ͖ ZĞǀŝĞǁ ĨŽƌ &ƵƚƵƌĞ ZĞƐĞĂƌĐŚ KƉĞŶŝŶŐƐ͟

͞/ƌŽŶ KdžŝĚĞ EĂŶŽƉĂƌƚŝĐůĞƐ ĂƐ ŽŶƚƌĂƐƚ ŐĞŶƚƐ ĨŽƌ DĂŐŶĞƚŝĐ ZĞƐŽŶĂŶĐĞ /ŵĂŐŝŶŐ ƉƉůŝĐĂƚŝŽŶƐ͟

͞hƐĞ ŽĨ ^ŚŽƌƚ ŵLJůŽŝĚŽŐĞŶŝĐ WĞƉƚŝĚĞƐ ĨŽƌ EĂŶŽƚĞĐŚŶŽůŽŐLJ͟

͞EĂŶŽĐŽĂƚŝŶŐƐ ĨŽƌ ĐŽƌƌŽƐŝŽŶ ƉƌŽƚĞĐƚŝŽŶ ŽĨ ƚŝƚĂŶŝƵŵ ĂůůŽLJƐ͟

͞DĂůĂƌŝĂ ŝĂŐŶŽƐƚŝĐƐ ďĂƐĞĚ ŽŶ ŶƚŝͲWůĂƐŵŽĚŝƵŵ ĨĂůĐŝƉĂƌƵŵ ,ZW// ŶƚŝďŽĚLJͲ&ƵŶĐƚŝŽŶĂůŝnjĞĚ 'ŽůĚ EĂŶŽƉĂƌƚŝĐůĞƐ͟

͞^ƚƌŽŶŐůLJ ĂŶŝƐŽƚƌŽƉŝĐ ǁĞƚƚŝŶŐ ŽŶ ŚŝŐŚůLJͲƵŶŝĨŽƌŵ ƐĞůĨͲƐŝŵŝůĂƌ ŵŽůLJďĚĞŶƵŵ ŶĂŶŽŐƌŽŽǀĞƐ͟

ƉŽƐƚĞƌ ƚŝƚůĞ

DĂĐŚĂĚŽ͕ ĞůƐŽ ůďƵƋƵĞƌƋƵĞ ZĞŝƐ͕ /ŶġƐ ͘ 'ŽŶĕĂůǀĞƐ͕ ^ĂůĞƚƚĞ ZĞŝƐ͕ D ƌŝƐƚŝŶĂ > DĂƌƚŝŶƐ

^ĞĂďƌĂ͕ ĂƚĂƌŝŶĂ >ĞĂů ůĄƵĚŝĂ EƵŶĞƐ͕ DĂƌƚĂ ŽƌƌĞŝĂ͕ :ŽƐĠ ĂƌůŽƐ EĂŶŽŵĂƚĞƌŝĂůƐ ͞^ƵƌĨĂĐĞ

K͘E͘ 'ŽƌƐŚŬŽǀ͕ ͘ <ĂƐĂƚŬŝŶ͕ /͘ ŶƚŽŶŽǀ͕ ͘ <ŽƌŽůĞǀ͕ ͘E͘ DŝŬŚĂLJůŽǀ͕ E͘ ͘^ŽďŽůĞǀ

ZŽƐĄƌŝŽ͕ ĂƌůŽƐ

>ƵşƐ &ƌĞĚĞƌŝĐŽ WŝŶŚĞŝƌŽ ŝĐŬ

ZŽĚƌşŐƵĞnj WĠƌĞnj͕ /ƐĂĂĐ

Z͘ ͘ ^ŝůǀĂ͕ ^͘K͘ &ĞƌƌĞŝƌĂ͕ t͘ ͘ DŽƵƌĂͲDĞůŽ͕ ͘Z͘ WĞƌĞŝƌĂ ĂŶĚ ͘/͘>͘ ĚĞ ƌĂƵũŽ

ZŝďĞŝƌŽ͕ /ŐŽƌ

ŶĚƌĠ Z͘d͘^͘ ƌĂƵũŽ͕ DĂƌŝĞƚĂ >͘ ͘ WĂƐƐŽƐ͕ D͘ >ƷĐŝĂ D͘ &͘ ^͘ ^ĂƌĂŝǀĂ

WŝŶƚŽ͕ WĂƵůĂ

:͘ ^͘ ŵĂƌĂů͕ E͘ :͘ K͘ ^ŝůǀĂ͕ s͘ ^͘ ŵĂƌĂů

WĞƌĞŝƌĂ͕ DĂƌŝĂ

WĞĐŝ͕ dĂnjĞ

^͘ ^ŽĨŝĂ D͘ ZŽĚƌŝŐƵĞƐ͕ ŚƌŝƐƚŝĂŶ &ƌŝŐĞƌŝŽ͕ :ŽĆŽ >͘ D͘ ^ĂŶƚŽƐ͕ D͘ >ƷĐŝĂ D͘ &͘ ^͘ ^ĂƌĂŝǀĂ

WĂƐƐŽƐ͕ DĂƌŝĞƚĂ

DĂƌĐŝŶ 'ƌŽďĞůŶLJ͕ DĂųŐŽƌnjĂƚĂ <ĂůŝƐnj

KƌŶŽǁƐŬŝ͕ DĂƌĐŝŶ

ĂƌŽůŝŶĂ 'ŽŶĕĂůǀĞƐ͕ /ŶġƐ ͘ 'ŽŶĕĂůǀĞƐ͕ &ĞƌŶĆŽ ͘ DĂŐĂůŚĆĞƐ

DŽƌĞŝƌĂ WŝŶƚŽ͕ ƌƚƵƌ

D͘ :͘ WĞƌĞŝƌĂ͕ E͘ D͘ &ŽƌƚƵŶĂƚŽ͕ :͘ ^͘ ŵĂƌĂů͕ ͘ ͘ >ŽƵƌĞŶĕŽ͕ :͘ D͘ sŝĞŝƌĂ

DŽŚƐĞŶŝ͕ &ĂƌnjŝŶ

ĂƵƚŚŽƌƐ

WŽƌƚƵŐĂů

WŽƌƚƵŐĂů

ƌĂnjŝů

ƌĂnjŝů

WŽƌƚƵŐĂů

WŽƌƚƵŐĂů

h<

WŽƌƚƵŐĂů

WŽůĂŶĚ

WŽƌƚƵŐĂů

WŽƌƚƵŐĂů

ĐŽƵŶƚƌLJ

EĂŶŽďŝŽͬEĂŶŽDĞĚŝĐŝŶĂ

KƚŚĞƌ

EĂŶŽŵĂƚĞƌŝĂůƐ

EĂŶŽŵĂƚĞƌŝĂůƐ

EĂŶŽ ŚĞŵŝƐƚƌLJ

EĂŶŽŝŶƐƚƌƵŵĞŶƚĂƚŝŽŶ

EĂŶŽďŝŽͬEĂŶŽDĞĚŝĐŝŶĞ

EĂŶŽ ŚĞŵŝƐƚƌLJ

KƚŚĞƌ

EĂŶŽďŝŽͬEĂŶŽDĞĚŝĐŝŶĞ

EĂŶŽŵĂƚĞƌŝĂůƐ

ƚŽƉŝĐ

͞EĂŶŽĞŶĐĂƉƐƵůĂƚŝŽŶ ŝŵƉƌŽǀĞƐ ƚŚĞ ĂŶƚŝďĂĐƚĞƌŝĐŝĚĂů ĞĨĨĞĐƚ ŽĨ ĚŽĐŽƐĂŚĞdžĂĞŶŽŝĐ ĂĐŝĚ ĂŐĂŝŶƐƚ ,ĞůŝĐŽďĂĐƚĞƌ ƉLJůŽƌŝ͟

͞ZĞƐŝƐƚŝǀĞ ƐǁŝƚĐŚŝŶŐ ĂŶĚ ŝŵƉĞĚĂŶĐĞ ƐƉĞĐƚƌŽƐĐŽƉLJ ŝŶ ŵĞƚĂůͲŽdžŝĚĞͲ ŵĞƚĂů ƚƌŝůĂLJĞƌƐ ǁŝƚŚ ^ŝKdž ĂŶĚ ƌKϮ͗ Ă ĐŽŵƉĂƌĂƚŝǀĞ ƐƚƵĚLJ͟

͞^LJŶƚŚĞƐŝƐ ŽĨ ,ŝŐŚ ĨĨĞĐƚŝǀĞ ^ƵƌĨĂĐĞ ƌĞĂ ^ŝůǀĞƌ EĂŶŽƉĂƌƚŝĐůĞƐ ŵďĞĚĚĞĚ ŝŶ WŽƌŽƵƐ ůƵŵŝŶĂ DĂƚƌŝdž hƐŝŶŐ ƚŚĞ DĞůƚ ^ƉŝŶŶŝŶŐ WƌŽĐĞƐƐ͟

͞WƌĞƉĂƌĂƚŝŽŶ ĂŶĚ ĐŚĂƌĂĐƚĞƌŝnjĂƚŝŽŶ ŽĨ ĂŶƚŝĚŽƚĞ ĐŽŵƉůĞŵĞŶƚ ŽĨ ƐƋƵĂƌĞ ĂƌƚŝĨŝĐŝĂů ƐƉŝŶ ŝĐĞ͟

͞dŚĞ ĂƐƐĞŵďůLJ ŽĨ ƚŚĞ ŶĂŶŽƉĂƌƚŝĐůĞͲďĂƐĞĚ ĂƐƐĂLJƐ ǁŝƚŚ ĂƵƚŽŵĂƚŝĐ ĨůŽǁ ƐLJƐƚĞŵƐ͗ ƉŽƚĞŶƚŝĂůŝƚŝĞƐ ĂŶĚ ůŝŵŝƚĂƚŝŽŶƐ ͟

͞^ĐĂŶŶŝŶŐ dŚĞƌŵĂů DŝĐƌŽƐĐŽƉLJ͗ ƵŶƌĂǀĞůŝŶŐ ĂŶĚ ŵĂƉƉŝŶŐ ƚŚĞƌŵĂů ƉŚĞŶŽŵĞŶĂ Ăƚ ƚŚĞ ŶĂŶŽƐĐĂůĞ͟

͞'Ěϯн &ƵŶĐƚŝŽŶĂůŝnjĞĚ /ƌŽŶͲ&ŝůůĞĚ DƵůƚŝͲtĂůůĞĚ ĂƌďŽŶ EĂŶŽƚƵďĞƐ ĨŽƌ DZ/ /ŵĂŐŝŶŐ ĂŶĚ DĂŐŶĞƚŝĐ ,LJƉĞƌƚŚĞƌŵŝĂ ĂŶĐĞƌ dŚĞƌĂƉLJ͟

͞ ĚƐŽƌƉƚŝŽŶ ĞƋƵŝůŝďƌŝƵŵ͕ ŬŝŶĞƚŝĐƐ ĂŶĚ ƚŚĞƌŵŽĚLJŶĂŵŝĐƐ ŽĨ ĚdĞ ƋƵĂŶƚƵŵ ĚŽƚƐ ǁŝƚŚ ĚŝƐƚŝŶĐƚ ĐĂƉƉŝŶŐƐ ƵƐŝŶŐ ĚŝĨĨĞƌĞŶƚ ƐŽůŝĚ ƐƵƉƉŽƌƚƐ͟

͞dŚĞ ŝŶĨůƵĞŶĐĞ ŽĨ ƐƵƌĨĂĐĞ ƉƌĞƉĂƌĂƚŝŽŶ ŽŶ ƚŚĞ ĐŽƌƌŽƐŝŽŶ ĂŶĚ ŵĞĐŚĂŶŝĐĂů ƉƌŽƉĞƌƚŝĞƐ ŽĨ dŝϲ ůϰs ƚŝƚĂŶŝƵŵ ĂůůŽLJ͟

͞ ĨĨĞĐƚ ŽĨ ďŝŽĚĞŐƌĂĚĂƚŝŽŶ ŽŶ W> ͬŐƌĂƉŚĞŶĞͲŶĂŶŽƉůĂƚĞůĞƚƐ ĐŽŵƉŽƐŝƚĞƐ ŵĞĐŚĂŶŝĐĂů ƉƌŽƉĞƌƚŝĞƐ ĂŶĚ ďŝŽĐŽŵƉĂƚŝďŝůŝƚLJ͟

͞DĂŐŶĞƚŝĐ ĂŶĚ ŵŽƌƉŚŽůŽŐŝĐ ƉƌŽƉĞƌƚŝĞƐ ŽĨ ůŶŝĐŽͲďĂƐĞĚ ƌĂƌĞͲ ĞĂƌƚŚ ĨƌĞĞ ƉĞƌŵĂŶĞŶƚ ŵĂŐŶĞƚƐ͟

ƉŽƐƚĞƌ ƚŝƚůĞ

ĂƵƚŚŽƌƐ

:͘ ĚĂŵŽǁƐŬŝ͕ D͘ tŽųŽƐnjLJŶ͕ ͘:͘ ^ƉŝƐĂŬ

tŽũĐŝŬ͕ WĂǁĞů

&͘ ZŝǀĞƌĂͲ>ſƉĞnj

sĂƐĐŽŶĐĞůŽƐ͕ ,ĞůĞŶĂ

,ĞŶƌŝŬ ,ĂƐƉĞů͕ ŬŽƐ <ƵŬŽǀĞĐnj͕ ŽůƚĄŶ <ſŶLJĂ

sĂƌŐĂ͕ dĂŵĄƐ

ƌŝƐƚŝĂŶĞ DŽƌĂŝƐ ^ŵŝƚŚ͕ ĂŶĚ sůĂĚŝŵŝƌ :ƵƌŝĐŝĐ

ǀĂŶ DŝĞƌƚ͕ 'ƵŝĚŽ

:͘ ͘ ŽƐƚĂ͕ :͘ ŽƌŵĞ͕ D͘ 'ŽŶnjĂůĞnjͲ ĞďƐ͕ ͘ >ĂĐŽƐƚĞ͕ ͘ WĂnj͕ ^͘ ^ĞƌƌĂŶŽͲ'ƵŝƐĂŶ͕ Z͘ &ĞƌƌĞŝƌĂ ĂŶĚ W͘ &ƌĞŝƚĂƐ

dĂƌĞƋƵnjnjĂŵĂŶ͕ DŽŚĂŵŵĂĚ

DŽŚĂŵĞĚ

^ĞĂŚ͕ ŚŽŽŶ DŝŶŐ

EĂŶŽŵĂƚĞƌŝĂůƐ ͞^ƵƌĨĂĐĞ ƌŝŐŝƚƚĞ sŝŐŽůŽ͕ ^ŝĂŶŐͲWŝĂŽ ŚĂŝ͕ ďĚƵů ZĂŚŵĂŶ

WŽůĂŶĚ

WŽƌƚƵŐĂů

,ƵŶŐĂƌLJ

EĞƚŚĞƌůĂŶĚƐ

WŽƌƚƵŐĂů

&ƌĂŶĐĞ

ĐŽƵŶƚƌLJ

͞^LJŶƚŚĞƐŝƐ ĂŶĚ ĐŚĂƌĂĐƚĞƌŝƐĂƚŝŽŶ ŽĨ ŐƌĂƉŚŝƚĞ ŽdžŝĚĞͬǀĂŶĂĚĂƚĞ ŶĂŶŽǁŝƌĞ ĐŽŵƉŽƐŝƚĞƐ͟

͞^ƉŝŶͲŽƌďŝƚ ĐŽƵƉůŝŶŐ ŝŶ ŐƌĂƉŚLJŶĞƐ͟

͞>ĂƌŐĞ ƉŽǁĞƌ ĞŵŝƐƐŝŽŶ ŝŶ Dd: ďĂƐĞĚ ƐƉŝŶ ƚŽƌƋƵĞ ŶĂŶŽͲŽƐĐŝůůĂƚŽƌƐ ƵƐŝŶŐ Ă ĨƌĞĞ ůĂLJĞƌ ŶĞĂƌ ƚŚĞ ŝŶͲƉůĂŶĞ ƚŽ ŽƵƚ ŽĨ ƉůĂŶĞ ƚƌĂŶƐŝƚŝŽŶ͟

͞ Ŷ /ŵƉƌŽǀĞĚ tĞƚ ŚĞŵŝĐĂů ƉƉƌŽĂĐŚ &Žƌ dŚĞ ^ĞƉĂƌĂƚŝŽŶ KĨ 'ƌĂƉŚĞŶĞ &ƌŽŵ EŝĐŬĞů &Žŝů dŽ dŚĞ ZĞƵƚŝůŝnjĂƚŝŽŶ KĨ ĂƚĂůLJƐƚ͟

ƉŽƐƚĞƌ ƚŝƚůĞ

DŽĚĞůŝŶŐ Ăƚ ƚŚĞ ŶĂŶŽƐĐĂůĞ

͞'ĞŶĞƌĂƚŝŶŐ ĂŶĚ ĞƚĞĐƚŝŶŐ ƚŚĞ ^ƉŝŶ ƵƌƌĞŶƚ ŝŶ zͲƐŚĂƉĞĚ ^ĞŵŝĐŽŶĚƵĐƚŽƌ EĂŶŽǁŝƌĞ ǁŝƚŚ YƵĂŶƚƵŵ WŽŝŶƚ ŽŶƚĂĐƚ͟

KƉƚŝĐƐͬWŚŽƚŽŶŝĐƐͬWůĂƐŵŽŶŝĐƐ ͞yW^ ĂŶĚ shs ƐƚƵĚŝĞƐ ŽĨ EͲĚŽƉĞĚ dŝKϮ ^ŽůͲ'Ğů &ŝůŵƐ͟

'ƌĂƉŚĞŶĞͬEĂŶŽƚƵďĞƐ

EĂŶŽŵĂƚĞƌŝĂůƐ

KƚŚĞƌ

'ƌĂƉŚĞŶĞͬEĂŶŽƚƵďĞƐ

ƚŽƉŝĐ

Mechanosynthesis and Spark Plasma Sintering of Fine-Grained Na1/2Bi1/2Cu3Ti4O12 Ceramics with Giant Dielectric Response Mohamad M. Ahmad Department of Physics, College of Science, King Faisal University, Al-Asia, Saudi Arabia mmohamad@kfu.edu.sa Abstract Materials with high values of the dielectric constant are technologically important for their use in various microelectronics applications, such as the components involved in charge storage capacitors. Giant dielectric constant (GDC) was discovered in the ACu3Ti4O12 (ACTO) family of materials, where A = Ca, La2/3, Y2/3, Bi2/3, Na0.5Bi0.5, etc, with CaCu3Ti4O12 (CCTO) is the most studied example material [1-3].

4 5 These materials, with the perovskite structure, exhibit dielectric values up to H¶ a -10 that is almost independent of temperatures and frequencies over wide ranges [1-3]. The observed (GDC) is due to internal barrier layer capacitance (IBLC) effects that originate from the presence of semiconducting grains separated by resistive grain boundaries [2,3]. The GDC oxide materials are usually prepared by solid state reaction followed by conventional sintering, leading to coarse grained ceramics. It is widely accepted that the dielectric permittivity will increase with increasing the grain size from few to hundreds Pm [4]. However, we have reported recently that CCTO nanoceramics with grain size in the 100 ± 200 nm exhibit GDC similar to the coarse grained ceramics [5]. In the current work we study the dielectric response of fine-grained Na0.5Bi0.5Cu3Ti4O12 (NBCT) ceramics.

NBCT was synthesized by mechanosynthesis at RT using stoichiometric proportions of Na2CO3, Bi2O3, CuO and TiO2. The milling process was performed in Fritsch P-7 machine using tungsten carbide pots and balls, where the balls to powder mass ratio was 8:1. The milling process continued for 30 h with a rotation speed of 450 rpm. NBCT ceramics were obtained by SPS at 800, 850 and 900 °C using SPS 4-10 system (Thermal Technology LLC). The SPS experiments were performed in a 20 mm graphite die under 60 MPa pressure with a heating rate of 150 °C/min and the dwelling time was fixed to 10 min followed by rapid cooling. The product materials were characterized by XRD and FE-SEM techniques. Impedance measurements were conducted in the 120 ± 400 K temperature range over the 1 Hz ± 40 MHz frequency range using Novocontrol concept 50 system.

XRD patterns of the SPS ceramics in Fig. 1(e) show the formation of the perovskite structure of the NBCT ceramics. SEM micrograph [Fig. 1(a-d)] of the mechanosynthesized powder shows that nanopowder with particle size < 50 nm was obtained. The grain size of the SPS ceramics increased to 250-450 nm with increasing the SPS temperature from 800 to 900 °C. The grain size of the current ceramics is one order of magnitude smaller than that obtained by conventional sintering. The frequency dependence of the dielectric constant of SPS-900 ceramics is shown in Fig. 2(a). At low frequencies, a 4 plateau region exists with a dielectric value of ~ 3.0 x 10 . At high frequencies the dielectric constant drops to a value of ~ 200, which represent the bulk response. The frequency dependence of the dielectric constant of SPS-800, SPS-850 and SPS-900 ceramics at 300 K is shown in Fig. 2(b). We notice that all the NBCT fine-grained ceramics hive very similar dielectric values. This is a result of the close grain size of the investigated materials. The transport properties of the current ceramics are studied though impedance spectroscopy. The impedance diagrams for SPS-900 ceramics are shown in Fig. 3(a). In this figure two semicircles are observed; a large one at the low frequency side, which is due to grain boundary contributions and a high frequency semicircle which is assigned to the bulk response.

The temperature dependence of the grain and grain boundary conductivity is presented in Fig. 3(b). We notice that the grain conductivity is much larger than the grain boundary conductivity, supporting the IBLC model. However, the grain boundary conductivity in the SPS NBCT ceramics is very high (~ 2.7 x -3 10 S/cm at 300 K) compared to the ceramics prepared by conventional sintering with a value of ~ 5 x -6 10 S/cm [6]. The activation energy of the grain conduction is 0.089 eV, which agrees with the other ACTO GDC materials. However, the activation energy of the grain boundary contribution is 0.192 eV, which is much smaller than the value of ~ 0.5 ± 0.6 eV that usually reported for GDC materials.

References [1]M. A. Subramanian, D. Li, N. Duan, B. A. Reisner, and A. W. Sleight, J. Solid State Chem., 151 (2000) 323.

[2]D. C. Sinclair, T. B. Adams, F. D. Morrison, and A. R. West, Appl. Phys. Lett., 80 (2002) 2153.

[3]M. C. Ferrarelli, T. B. Adams, A. Feteira, D. C. Sinclair, and A. R. West, Appl. Phys. Lett., 89 (2006) 212904.

[4]T. B. Adams, D. C. Sinclair, and A. R. West, Adv. Mater., 14 (2002) 1321.

[5]M. M. Ahmad, Appl. Phys. Lett., 102 (2013) 232908.

[6]H. Ren, P. Liang and Z. Yang, Mater. Res. Bull., 45 (2010) 1608.

(e)

Intensity (A.U)

SPS-900

SPS-850

SPS-800

20

30

40

50 2Tq

60

70

80

Figure 1. SEM micrographs of (a) NBCT nanopowder and (b-d) SPS-800, SPS-850 and SPS-900, respectively. (e) XRD patterns of SPS NBCT ceramics.

5

5

(a)

4

(b)

log H'

log H'

4 150 K 180 K 210 K 240 K 270 K 300 K

3

2

3 SPS-800 SPS-850 SPS-900

2 1

2

3

4 5 log f (Hz)

6

7

8

1

2

3

4 5 log f (Hz)

6

7

8

Figure 3. (a) frequency dependence of the dielectric constant for (a) SPS-900 sample and (b) for all ceramics at 300 K. -1

log Vdc (S/cm)

-2 -3 -4 -5 -6 3

4

5 6 7 1000/T (1/K)

8

9

Figure 4. (Left graph) Complex impedance diagrams for SPS-900 ceramics at different temperatures.

The inset shows the impedance of the grains at high frequencies. (Right graph)) The temperature dependence of the grain (closed squares) and grain boundary (closed circles) conductivities of SPS-900 ceramics.

Functionalized Solid Lipid Nanoparticles: a theranostic approach for the treatment of Rheumatoid Arthritis João Albuquerque, Catarina Costa Moura, Bruno Sarmento, Salette Reis REQUIMTE, Departamento de Ciências Químicas, Faculdade de Farmácia, Universidade do Porto, Rua de Jorge Viterbo Ferreira n.º 228, 4050-313 Porto, Portugal joao.albuquerque,costa@gmail.com

Abstract Rheumatoid Arthritis (RA) is the most common autoimmune disease related to the joints and one of the most severe. Despite the intensive investigation, RA inflammatory process remains unknown and finding effective and long lasting therapies that specifically target RA is a challenging task. In RA the pro-inflammatory macrophages persist in the inflammation site and frequently overexpress cytokines and other biomolecule factors that amplify even more the inflammatory process. However, during RA, the macrophages also overexpress the CD64 surface marker that drives the search for new specific RA therapies.

This work proposed an innovative approach for RA therapy, taking advantage of the new emerging field of nanomedicine and the tools that it offers for targeted therapies. This study aimed to develop a targeted theranostic system for intravenous administration, using Solid Lipid Nanoparticles (SLN), a biocompatible and biodegradable colloidal delivery system, widely researched for medical applications, to function as a drug delivery system. The SLNs were encapsulated with methotrexate (MTX) and superparamagnetic iron oxide nanoparticles (SPIONs), to be used as therapeutic and imaging agents, respectively. The SLNs were also surface-functionalized with an anti-CD64 antibody that specifically targets RA-infected macrophages.

A total of eight different cetyl palmitate and stearic acid SLN formulations were produced using in an organic solvent-free emulsification-sonication method that combined high shear homogenization and ultra-sonication in order to compare the influence of each component present (MTX, SPIONs and antiCD64) on NP characteristics. Particle size was assess by dynamic light scattering and analyzed by transmission electron microscopy and surface charge (zeta potential) mas measured by phase analysis light scattering. The placebo formulations showed sizes around 160 nm and zeta potentials of ± 40 mV. Results also showed that MTX did not influence significantly NP properties, whereas SPIONs encapsulation caused an increase in both size and zeta values. The antibody conjugation caused an increased in zeta potential as expected but an unexpected decrease in NP size was observed.

However, all the formulations presented sizes below 200 nm and zeta values lower than -12 mV, indicating suitable characteristics as nanosystems for intravenous administration. The stability of these formulations was also proven up to one month for the non-conjugated formulations. Nanoparticle morphology was analyzed by transmission electron microscopy (TEM).

TEM photographs indicated that the SPIONs were encapsulated inside the SLN matrix. Also, it was possible to observe small deformity and aggregation of NPs, while formulations without SPIONs presented a spherical shape with little aggregation. FT-IR was used to confirm the presence of MTX in the SLNs as well as the successful conjugation of the antibody to the SLN. MTX association efficiency

was determined by UV/Vis spectrophotometry, rendering values non-lower than 98% for both MTXloaded SLNs and MTX- and SPIONs-loaded SLNs. In vitro studies were performed with THP-1 cells and enabled to assess the cytotoxicity of the developed formulations. MTT and LDH assays demonstrated that the formulations were biocompatible and presented low cytotoxicity a concentrations lower than 500 Âľg/mL, but there were no significant changes when comparing the different formulations at the same concentrations unexpectedly.

This study could provide an effective and viable approach for future theranostic strategies. It was proven that the proposed NP were not cytotoxic, that both a therapeutic and imaging agent could be coencapsulated and the SLN functionalized for a potential future application such as anti-body specific targeting. The proposed formulations are, therefore, promising candidates for future theranostic applications.

Figures

Figure 1 Âą Schematic representation of the proposed theranostic strategy for the treatment of RA.

Surpassing NSAIDs side-effects with Lipid Nanoparticles Araújo J., Neves, A. R., Gouveia, V., Moura, C., Nunes, C. and Reis, S. REQUIMTE, Laboratório de Química Aplicada, Faculdade de Farmácia, Universidade do Porto Rua de Jorge Viterbo Ferreira n.º 228, 4050-313, Porto, Portugal bio09089@fe.up.pt The inflammatory process is the innate immune response for the presence of pathogens, toxic molecules, tissue injuries or any other harmful conditions. The inflammation process is characterized for redness, pain, swelling, heat and disturbance of function and comprises inducers, sensors, mediators and effectors components from cellular and humoral origin. Macrophages are one of the most important cells in the inflammatory process. Macrophages actively phagocyte particles with sizes superiors to 200 nm and express folate receptor making them of great interest for passive and active targeting strategies.

Non-Steroidal Anti-Inflammatory Drugs, like oxaprozin, are one of the most used drugs prescribed for these conditions, however these drugs have adverse side effects, namely at the level of the gastric mucosa, that must be avoided and pharmacokinetic properties that need to be improved and for these purpose many delivery systems arise. Lipid Nanoparticles allow an effective drug packaging and targeted delivery, improving drug´s pharmacokinetics and pharmacodynamics properties and avoiding some of their side effects. In this work, two formulations containing oxaprozin were developed: nanostructured lipid carriers with and without folate functionalization obtained by the addition of a synthesised DSPE-PEG2000-FA conjugate. These formulations revealed high stability, low polydispersity and mean diameters that allowed macrophages passive targeting along with high encapsulation and loading capacity. The formulations avoided the oxaprozin release in simulated gastric fluid promoting its release on simulated intestinal fluid, physiologic and inflammatory medium, remaining only a small amount entrapped on the lipid carrier matrix. MTT and LDH assays revealed that the formulations only seemed to present cytotoxicity in Caco-2 cells, for oxaprozin concentratiRQV VXSHULRUV WR ȝ0 DQG permeability studies in the same cell line shown that oxaprozin encapsulation on the lipid nanoparticles did not interfere with oxaprozin permeability.

Targeting of Plasmodium transmission stages with polymers-FITC for future antimalarial delivery strategies 1

2

2

1

3

Joana Marques , Michael Delves , Ursula Straschil , Elisabet Martí , Elisabetta Ranucci , Paolo 3 2 1 Ferruti , Robert Sinden , Xavier Fernàndez-Busquets 1. Institute for Bioengineering of Catalonia, Barcelona Centre for International Health Research, Centre Esther Koplowitz planta 1, Rosselló 149-153, E08036 Barcelona, Spain 2. Sinden Lab, Imperial College, 6th Floor SAF Building, South Kensington, London, SW7 2AZ, UK 3. Department of Chemistry, Università degli Studi di Milano, Via Golgi 19, IT-20133 Milano, Italy joana.a.marques@gmail.com With malaria elimination now firmly on the global research agenda, but resistance to the currently available drugs on the rise, there is an urgent need to invest in the research and development (1) of new antimalarial strategies . Drugs can potentially target a suite of parasite life stages inside two different hosts: the human and the mosquito vector.

Asexual blood stages are responsible for all symptoms and pathologies of malaria, and therefore resident parasites inside Plasmodium-infected RBCs (pRBCs) are the main target for current (2) chemotherapeutic approaches . As there can be several hundred billion pRBCs in the bloodstream of a malarious person it is nearly impossible to clear infections with single-dose administrations. Multiple doses are required instead and this continuous exposure to drugs increases the likelihood for resistance to develop, which will rapidly decrease treatment efficacy. This is prompting research oriented to target bottlenecks in the parasite life cycle, i.e. the pathogen population consisting of a few individuals in (3,4,5) certain transmission stages from the human host to the insect and vice versa , which will reduce the (6) probability of resistance emergence .

Although the innate immune system of mosquitoes is capable of completely clearing a malaria (7) infection , it is far from the sophisticated arsenal providing long-term protection in mammalian adaptive immunity. This might result in parasite stages with reduced defenses because they only need to survive for a few weeks inside the insect facing an immune surveillance not as demanding as in the human 3 host. Drugs targeting early Anopheles stages must kill only ca. 5 x 10 parasites to free a mosquito from (8) Plasmodium infection , and the absolute low corresponds to oocysts, of which there are only 2-5 in a (5) single insect and which are around for over a week.

Previous results obtained by our group indicated that certain polymers can have a dual role as (9,10) antimalarial drugs and as targeting elements towards pRBCs . Thus, we explored if these polymers could also be targeting agents against the Plasmodium mosquito stages (gametocytes, sporozoites, ookinetes, and oocysts).

This work was supported by grants BIO2011-25039 from the Ministerio de Economía y Competitividad, Spain, which included FEDER funds; 2009SGR-760 from the Generalitat de Catalunya, Spain; Xarxa Eurolife from Universitat de Barcelona; and 2013-0584 from the Fondazione CARIPLO, Italy.

References 1. Alonso PL , Tanner M: Public health challenges and prospects for malaria control and elimination. Nat.Med. 19(2), 150-155 (2013).

2. Griffith KS, Lewis LS, Mali S, Parise ME: Treatment of malaria in the United States: a systematic review. JAMA 297(20), 2264-2277 (2007).

3. Sinden R, Carter R, Drakeley C, Leroy D: The biology of sexual development of Plasmodium: the design and implementation of transmission-blocking strategies. Malar.J. 11(1), 70- (2012).

4. Delves MJ, Ramakrishnan C, Blagborough AM, Leroy D, Wells TNC, Sinden RE: A high-throughput assay for the identification of malarial transmission-blocking drugs and vaccines. Int.J.Parasitol. 42(11), 999-1006 (2012).

5. Delves MJ: Plasmodium cell biology should inform strategies used in the development of antimalarial transmissionblocking drugs. Future Med.Chem. 4(18), 2251-2263 (2012).

6. Delves M, Plouffe D, Scheurer C et al: The activities of current antimalarial drugs on the life cycle stages of Plasmodium: a comparative study with human and rodent parasites. PLoS Med. 9(2), e1001169-e1001169 (2012).

7. Marois E: The multifaceted mosquito anti-Plasmodium response. Curr.Opin.Microbiol. 14(4), 429-435 (2011).

8. Sinden R: A biologist's perspective on malaria vaccine development. Hum.Vaccin. 6(1), 3-11 (2010).

9. Marques J, Moles E, Urbán P et al: Application of heparin as a dual agent with antimalarial and liposome targeting activities towards Plasmodium-infected red blood cells. Nanomedicine: NBM 10, 1719-1728 (2014).

10. Urbán P, Valle-Delgado JJ, Mauro N et al: Use of poly(amidoamine) drug conjugates for the delivery of antimalarials to Plasmodium. J.Control.Release 177, 84-95 (2014).

Figure 1. Targeting assay of the 5 polymers in study to Plasmodium berghei ookinetes. Polymers labelled with FITC were added to living cultures of P. berghei ookinetes and incubated for 90 minutes before sample preparation for microscopic analysis. Each series shows ookinetes (arrowheads) and pRBCs (arrows) as control of the specificity of the targeting. Scale bars correspond to 10 Âľm.

Water-Dispersible Silver Nanoclusters: Synthesis and Characterization José M. Blancoa, Javier Calvod, Enrique Carbó Argibaya, Erea Borrajo Alonsoc, Fernando Domínguezc, M. Arturo López Quintelab, and José Rivasa,b aInternational Iberian Nanotechnology Laboratory, 4715-330 Braga-Portugal de Magnetismo y Nanotecnología, Instituto de Investigaciones Tecnológicas, Universidad de Santiago de Compostela, E-15782, Santiago de Compostela, Spain cInstituto de Investigación Sanitaria de Santiago de Compostela (IDIS), 15706 Santiago de Compostela, Spain dNanogap, 15895 Milladoiro, A Coruña, Spain bLaboratorio

Abstract We report here a route to synthesize small water-dispersible silver nanoclusters (also known as Atomic Quantum Clusters - AQCs) in the absence of any type of surfactant or stabilizing agent, through an easy and versatile potentiostatic method based on a bottom-up electrochemical synthesis of nanoparticles 1.

The small size of the nanoclusters, comparable to Fermi wavelength of the electron (~0.52 nm for silver), places AQCs in the scale range where quantum confinement effects govern the material properties. Because of this, AQCs behave like molecules, displaying delocalized molecular orbitals, similar to those observed in HOMO and LUMO orbitals of single molecules, and exhibiting new and interesting physical and chemical properties derived from their small size, such as photoluminescence2,3 or magnetism4,5. The stability, biocompatibility and fluorescence of silver AQCs allow to apply them in very different fields, such as catalysis, biosensing and nanomedicine. In fact, results about the biological activity of silver sub-nanometric quantum clusters will be shown here. Different techniques were employed in order to characterize the structure of the synthesized silver nanoclusters, such as spectroscopy (UV-Vis, Fluorescence), mass spectrometry (ESI ± Electrospray Ionization), atomic force microscopy (AFM) and electrochemical techniques as for example cyclic voltammetry (CV). a)

b) 0.06

Ag5

0.04

Ag 2-3 0.02

Exc 230nm Exc 270nm Exc 310nm Exc 330nm Exc 350nm

Ag7

Ag6 Ag4

I/UE

Absorbance/UA

6

8.0x10

6

4.0x10

Ag2

Ag 4-7

0.00

Ag3

0.0

300

400

O nm

500

300

400

500

600

O nm

Fig 1. Characterization by Absorption and Fluorescence spectrophotometer of a sample of silver AQCs. a) UV-Vis absorption spectrum, b) Emission spectra measured at exciting wavelengths between 230 and 350 nm.

Acknowledgement: this work is supported by POCTEP (Operational Programme for Cross-border Cooperation Spain-Portugal), co-financed by the ERDF (European Regional Development Fund) under grant InveNNta Project.

1

Manfred, T. Reetz; Wolfgang Helbig., J. Am. Chem. Soc., 116 (16) (1994) 7401±7402.

Schaeffer, N.; Tan, B.; Dickinson, C.; Rosseinsky, M. J.; Laromaine, A.; McComb, D. W.; Stevens, M. M.; Wang, Y.; Petit, L.; Barentin, C.; Spiller, D.G.; Cooper, A. I.; Levy, R., Chem. Commun., (2008) 3986.

3 Haekkinen, H., Chem. Soc. Rev, 37 (2008) 1847.

4 Moro, R.; Yin, S.; Xu, X.; de Heer, W. A., Phys Rev Lett., 93 (2004) 086803.

5 Ledo-Suarez, A.; Rivas, J.; Rodriguez-Abreu, C.; Rodriguez, M. J.; Pastor, E.; Hernandez-Creus, A.; Oseroff, S.B.; Lopez Quintela, M. A., Angew. Chem. Int. Ed., 46 (2007) 8823.

2

Work Function and Gate Length Effect On Electrical Characteristics Of n-FinFET in 3D Using ATLAS SILVACO N. Boukortt

1,2,*

1

2

2

2

2

, B. Hadri , L. Torrisi , S. Patanè , A. Caddemi & G. Crupi

1

2

University of Mostaganem, Avenue Hamadou Hossine, Mostaganem, Algeria Universita` degli studi di Messina, V. F.S. d'Alcontres 31, 98166 s. Agata, Messina, Italy * Nour.Boukortt@yahoo.fr

Abstract This work investigates the threshold voltage, subthreshold slope and leakage current sensitivity to metal gate work function and gate length for a n-channel fin field-effect transistor (FinFET) in a 3-D structure using the numerical simulation tool Atlas Silvaco. Silvaco-Atlas was used to construct, examine and simulate the structure and characteristics of the FinFET device in three dimensions. Results were analyzed and presented to show that the threshold voltage is reduced with the decrease in gate work function and gate length. The behavior of the subthreshold slope and the leakage current improves with increased metal gate work function. The SCE in FinFET 3-D can reasonably be controlled and improved by proper adjustment of the metal gate work function. The obtained results also show that when there is a reduction of gate length the subthreshold slope decreases and leakage current increases giving a good saturation region in output characteristics (Ids-Vds). Simulation shows possible scaling to 8 nm gate length.

Keywords: Device Scaling, FinFET, Silicon On Insulator "SOI", work function, gate length, Silvaco Software.

References [1] Jean-Pierre Colinge, Springer Science & Business, (2007) 1-37.

[2] M. Mustafa, Tawseef A. Bhat, M. R. Beigh, World Journal of Nano Science and Engineering, 3 (2013) 17-22.

[3] Olivier Ezratty, Las Vegas Convention Center SOUTH HALLS - Ligaran (2014) p.289.

[4] S K Mohapatra , K P Pradhan and P K Sahu, Transactions On Electrical And Electronic Materials, 14 (2013) 291-294.

[5] C. Hu, Prentice Hall, (2010) 195-258.

[6] S. K. Mohapatra, K. P. Pradhan and P. K. Sahu, International Journal of Advanced Science and Technology, 65 (2014) 19-26.

[7] Ahlam Guen and Benyounes Bouazza, International Journal of Science and Advanced Technology, 2 (2012) 40-45.

[8] V. Narendar, Ramanuj Mishra, Sanjeev Rai, Nayana R and R. A. Mishra, International Journal of VLSI design & Communication Systems, 3 (2012) 175-191.

[9] Neeraj Gupta; A.K. Raghav; Alok K. Kushwaha, International Journal OF Technological Exploration And Learning, 3 (2014) 455-458.

[10] Yongho Oh and Youngmin Kim, Journal of Electrical Engineering & Technology, 1 (2006) 237-240.

[11] Abhinav Kranti and G Alastair Armstrong, Semicond. Sci. Technol, 21 (2004) 409-421.

[12] I. Flavia Princess Nesamani, Geethanjali Raveendran, Dr.V. Lakshmi Prabha, International Journal of Engineering Trends and Technology, 4 (2013) 299-301.

[13] Nagaratna Shanbhag, Kiran Bailey, Dr. K.S. Gurumurthy, International Journal of Science, Engineering and Technology Research, 3 (2014) 1381-1386

Figures

Fig 1. n-FinFET structure.

Fig 4. IDS-VDS characteristics.

Fig 2. IDS-VGS characteristics On linear scale.

Fig 4. IDS-VGS characteristics on linear scale.

Fig 3. IDS-VGS characteristics on log scale.

Fig 4. IDS-VGS characteristics on log scale.

Fig 4. . Threshold voltage versus gate work function.

Fig 4. . Leakage current versus gate work function.

Fig 4. IDS-VGS characteristics on log scale.

Fig 4. Threshold voltage versus gate length.

Fig 4. Subthreshold slope versus gate length.

Fig 4. Leakage current versus gate length

Low-temperature conversion of titanate nanotubes into nitrogen-doped TiO2 nanoparticles 1

1

%DOi]V %XFKKROF], Henrik Haspel, Ă&#x2C6;NRV .XNRYHF]

1,2

=ROWiQ .yQ\D

1,2,3

1

Department of Applied and Environmental Chemistry, University of Szeged, Rerrich %pOD Wpr 1, H-6720 Szeged, Hungary MTA-6=7( ¾¾/HQG OHWœœ 3RURXV 1DQRFRPSRVLWHV 5HVHDUFK *URXS 5HUULFK %pOD WpU H-6720 Szeged, Hungary 3 MTA-SZTE Reaction Kinetics and Surface Chemistry Research Group, 5HUULFK %pOD WpU H-6720 Szeged, Hungary konya@chem.u-szeged.hu Abstract 2

In the past two decades nanotubes have become the symbol of nanotechnology, a new and fast evolving field of science. Inorganic nanotubes with trititanate structure (Na xH2-xTi3O7) were first synthesized by Kasuga and coworkers. Their intention was to obtain TiO 2 with high specific surface area and enhanced photocatalytic activity. However, the applied alkaline treatment gave rise to morphological changes and tubular nanostructures with diameter of ~8 nm and length of ~100 nm appeared in the samples. Many possible applications of titanate nanotubes are known nowadays: high surface area mesoporous catalyst support, adsorbent, insoluble matrix for ion-exchange processes etc.

They are used in the development of lithium-ion batteries, in medical biology and are promising candidates for heterogeneous photocatalysis as well.

In our study titanate nanotubes were synthesized via the alkaline hydrothermal procedure. After a subsequent protonation step the obtained nanotubes were doped with nitrogen using ammonia formed in situ by the thermal decomposition of urea. This new method is an economic low temperature alternative to the existing gas phase N-doping procedures. Different nitrogen doping times were applied to the samples, followed by calcination steps at various temperatures, while changes in the morphology and phase were investigated. To this end, transmission and scanning electron microscopic (TEM, SEM), energy dispersive X-ray spectroscopic (EDS), X-ray and selective area electron diffraction (XRD, SAED) measurements were performed.

The increase in the nitrogen content and calcination temperature induced changes in the size and shape of the nanotubes, along with the transformation of the crystal structure. Nanotubes were first converted into anatase and then into rutile TiO2. The initial tubular morphology collapsed, and at low temperatures nanorods, while at higher temperatures nitrogen doped isometric nanoparticles were formed [1].

References [1] BuchhoOF] % +DVSHO + .XNRYHF] Ă&#x2C6; .yQ\D, Z. CrystEngComm, 16 (2014) 7486Âą7492.

Figures

Morphology and crystalline phase variation of nitrogen-doped titanium-oxide nanostructures with nitrogen doping and calcination temperature.

Metabolic effects of silver nanoparticles assessed by NMR metabolomics of mice liver and serum Joana Carrola1, Ivana Jarak1, Rui Silva1, António S. Barros2, Ana M. Gil1, M. Lourdes Pereira1, M. Luisa Corvo3, Iola F. Duarte1 1CICECO,

Departamento de Química, Universidade de Aveiro, Portugal Departamento de Química, Universidade de Aveiro, Aveiro, Portugal 3iMed.ULisboa,Departamento de Farmácia Galénica e Tecnologia Farmacêutica, Faculdade de Farmácia, Universidade de Lisboa, Lisboa, Portugal ioladuarte@ua.pt 2QOPNA,

Abstract Silver nanoparticles (Ag-NPs) are among the nanomaterials with highest propensity for human exposure, arising from their established use in wound dressings and increasing incorporation into consumer products (e.g. clothing, food packaging), mainly due to their remarkable antimicrobial properties. However, there is a narrow window between the bactericidal activity of Ag-NPs and their toxicity to human cells1, making the further understanding of their biological effects a relevant up-to-date subject. Development of metabolic profiling (metabolomics) strategies for assessing the cellular and systemic effects of these nanoparticles may provide a unique and important tool that can be broadly applied in the areas of nanotoxicology and nanomedicine2.

In this work, male mice were randomly divided into three groups, a control group (n 10) and two experimental groups (n 5 each) i.v. administered with Ag-NPs suspensions (1 mg/mL) and sacrificed at 24 and 48 hours post-injection. A complete necropsy was conducted on all mice. The necropsies included, but were not limited to, examination of the external surface, the cranial, thoracic, abdominal and pelvic compartments, including viscera. Liver, spleen, heart and kidneys were collected, rinsed with physiological serum and weighted. Tissue histopathology parameters and complete haemogram were also assessed. Based on a preliminary biodistribution study, liver tissues and blood serum were collected for metabolic profiling analysis. In particular, the samples were analysed by 1H Nuclear Magnetic Resonance (NMR) spectroscopy, using High Resolution Magic Angle Spinning (HRMAS) for direct tissue analysis, and the spectral data subjected to multivariate analysis, namely Principal Component Analysis (PCA) and Partial Least Squares Discriminant Analysis (PLS-DA), to highlight the metabolic differences between the groups.

The livers of control and Ag-NPs-exposed mice showed several significant differences in their metabolic composition, already apparent by simple visual inspection of 1H HRMAS spectra (Figure 1A).

Indeed, control and exposed groups showed a trend for separation in the PCA scores scatter plot and were clearly discriminated by PLS-DA (Figure 1B). The main metabolic alterations explaining this separation were in the levels of glucose, glycogen and reduced glutathione (decreased in exposed animals compared to controls) and in the levels of choline compounds and taurine (increased in mice exposed to nanoparticles for 24 and 48h, respectively). In regard to serum NMR profiles, while the most apparent alterations were in the levels of lipoprotein subclasses (Figure 2A), several other differences could be found in small metabolites, including increased levels of amino acids (alanine, valine, lysine, histidine, tyrosine, phenylalanine), creatine, choline and glycerol, together with decreased levels of glucose, acetate and fumarate. Interestingly, most of these changes showed a stronger magnitude at 24h than at 48h of Ag-NPs exposure, which explains the time-dependent group separation observed in the PCA and PLS-DA scores plots (Figure 2B). Overall, the results show that Ag-NPs, at a sublethal dose, disturb cellular and systemic metabolism, mainly affecting pathways involved in energy production and antioxidant protection.

References [1] Kim S and Ryu DY, J. Appl. Toxicol., 33 (2013) 78.

[2] Duarte IF, J. Control. Release 153 (2011) 34.

Figures A

B

Triglycerides

PCA

Glucose Choline compounds Glycogen

PLS-DA

5.00

4.00

3.00 ppm

2.00

1.00

ppm

Figure 1. A) Average 1H HRMAS NMR spectra of liver tissue from control mice (top), and mice exposed to Ag-NPs for 24h (middle) and 48h (bottom). B) Scores scatter plots obtained by PCA and PLS-DA of NMR liver spectra (ż FRQWUROV exposed 24h; S exposed 48h).

A

B PCA Glucose

LDL/ VLDL

Choline

HDL Creatine

Alanine

Acetate

4.50

4.00

3.50

3.00

2.50 ppm

2.00

1.50

PLS-DA

1.00

ppm

Figure 2. A) Average 1H NMR spectra of blood serum from control mice (top), and mice exposed to AgNPs for 24h (middle) and 48h (bottom). B) Scores scatter plots obtained by PCA and PLS-DA of NMR serum spectra (ż FRQWUROV exposed 24h; S exposed 48h).

FRET based gold nanobeacon for sequence discrimintation 1,2

1

Mílton Cordeiro , Pedro Viana Baptista , João Carlos Lima 1

2

REQUIMTE,Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa. Campus da Caparica, 2829-516 Caparica, Portugal.

2

Nanomedicine@FCT, UCIBIO, Departamento de Ciências da Vida, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa. Campus da Caparica, 2829-516 Caparica, Portugal.

! m.cordeiro001@gmail.com

Abstract We report development of a gold nanoparticle (AuNP) molecular beacon based biosensor coupled to a wavelength shift mediated by FRET, for the detection of fusion transcripts associated with the development of Chronic Myeloid Leukemia. Citrate capped 14 nm gold nanoparticles were functionalized with thiolade polyethylene glycol and further functionalized with a donor fluorophore labeled ssDNA with a hairpin structure. In the absence of a complementary target, the donor is in close proximity to the surface of the gold nanoparticle, leading to its quenching - gold nanoparticle are know to be fluorescence modulators [1-2]. Upon hybridization to the target sequence the donor breaks away from the surface of the gold nanoparticles due to the disruption of the hairpin structure, leading to a partial restoration of the donor fluorescence.

The disruption of the hairpin leads to the exposure of the palindromic sequence, allowing the hybridization of an acceptor labeled oligonucleotide – See figure 1. With the donor and acceptor in such proximity, FRET occurs leading to a wavelength shift of the hybridization fluorescence signal to wavelengths that are not affect by the high absorption of the AuNP.

References [1] Lakowicz J. R., Radiative decay engineering 5: metal-enhanced fluorescence and plasmon emission, Anal. Biochem., 337: 171–194 [2]- Rosa J., Lima J. C., Baptista P. V.,Experimental photophysical characterization% of fluorophores in the vicinity of gold nanoparticles, Nanotechnology,22:415202(7pp)(2011)

!

!

Figure 1. Schematic representation of the FRET based Au-nanoprobe. In the absence of a complementary target, the hairpin is in its closed conformation. Upon addition of complementary target (1), the closed conformation of the hairpin is disrupted and the donor breaks away from the surface of the AuNP, exposing the palindromic sequence that can hybridize to the acceptor labeled oligonucleotide (2).

Mechanosynthesis of supersaturated ternary solid solutions (FeCo)100-xSnx and their ordering by annealing at low temperature 1

2

B. F.O. Costa , B. Malaman and G. Le Caër

3

1 CEMDRX, Physics Department, University of Coimbra, P-3004-516 Coimbra, Portugal 2 Institut Jean Larmour, Départment P2M, Equipe 103, CNRS (UMR7198)- Université de Nancy, B.P. 70239, F-54506 Vandoeuvre-les-Nancy Cedex, France 3 IPR, UMR URI-CNRS 6251, Université de Rennes I, Campus de Beaulieu, Bat 11A, F-35042 Rennes Cedex, France benilde@fis.uc.pt; Bernard.malaman@ijl.nancy-universite.fr; gerard.le-caer@univ-rennes1.fr Abstract Iron-cobalt alloys have exceptional magnetic properties and are mechanically relatively strong [1]. Near-equiatomic FeCo alloys are bcc (A2) below ~1250K [1]. They order to a CsCl type structure (B2) at temperatures below ~1000K. A possible way to study alloys which tend to order is to prepare them by high-energy ball-milling HEBM from mixtures of elemental powders [2]. The as-milled alloys are generally in a metastable disordered state and may be ordered by annealing at well-chosen temperatures. We investigated recently the synthesis of metastable ternary alloys (FeCo)100-xSnx (x~ 033 at%) by HEBM [3, 4, 5]. The ternary system Fe-Co-Sn is essentially uninvestigated. The equilibrium solubility of Sn in FeCo (A2 or B2) is ~ 1 at% [6].

Milling of powder mixtures of Fe, Co and Sn was performed in argon atmosphere using a planetary Fritsch Pulverisette P6 mill. Alloys were annealed at 673K for 15h in quartz tubes sealed under vacuum. The evolution of the alloying process and the annealed alloys were characterized by X57 119 ray and neutron diffraction and by Fe and Sn Mössbauer spectroscopy.

X-ray diffraction patterns of ground powders show the presence of nanocrystalline disordered bcc phases (grain size ~4-8 nm). The lattice parameter a(x) increases steadily with Sn content till x 25 in a way fully consistent with the dissolution of Sn in FeCo as discussed in [3, 4, 5]. For alloys with Sn contents of 25 and 33 at% bcc Fe-Co-Sn alloys coexist with nanocrystalline hexagonal Co3Sn2 (see too figure 1). The maximum solubility of Sn in near-equiatomic Fe-Co is thus less than 25 at% Sn in our milling conditions, being of the order of 20 at% Sn. 57 119 Figures 1 and 2 present room temperature (RT) Fe and Sn Mössbauer spectra of as-milled alloys (FeCo)Snx (10h milling) and those of as-milled alloys annealed at 673K for 15h. Figure 3 shows the RT hyperfine magnetic field distributions (HMFD), P(H), of Fe44Co44Sn12 milled for 10h and then annealed at 673K for 15h. Neutron diffraction patterns are displayed in Figure 4 for (FeCo)100-xSnx (6 x 25) alloys milled during 10h and then annealed at 673K for 15h.

57 The average Fe HMF decreases when the Sn content increases in the as-milled state (fig. 1 left). The decrease is much less for annealed alloys (4 x 20) and the widths of the HMFD’s are smaller 57 for the annealed alloys (fig. 1 right). For x=12 (fig. 3 right) the average Fe HMF’s are 31.7 T and 32.7 T 57 in the as-milled and annealed alloy respectively. The Fe HMF’s are not very sensitive to chemical 119 order in these alloys. By contrast, the Sn HMF’s show a strong sensitivity to chemical order when dissolved in B2 FeCo (~0.3 at.%Sn) [6]. The HMF is about 25 T for Sn atoms which sit on the Co sublattice while it is as small as ‫׽‬0.7 T for those which sit on the Fe sublattice [6]. Figures 2 and 3 show 119 that the Sn spectra vary strongly when the as-milled alloys are annealed at 673K. For x=12 (fig. 3 left) 119 the average Sn HMF increases from 9.8 T to 16.3 T between the as-milled and the annealed states.

119 The maximum Sn HMF (fig. 3), 24.5 T, is close to the value measured for Sn dissolved in perfectly 119 ordered FeCo [6]. The ordering by annealing shown by Sn Mössbauer spectra is confirmed by neutron diffraction patterns (fig. 4) which evidence clearly the presence of (100) and (111) superlattice lines.

In summary, the maximum solubility of Sn in FeCo is considerably increased by HEBM. In our milling conditions the latter increases from ~1 at.% at thermal equilibrium to ~20 at. %. The metastable as-milled alloys are bcc and disordered. They order by annealing at moderate temperatures (here 673K) for any Sn content less than 20 at.%.

References [1] T. Sourmail, Prog. Mater. Sci. 50 (2005) 816 .

[2] C. Suryanarayana, Prog. Mater. Sci., 46 (2001) p.1 [3] J.M. Loureiro, B.F.O. Costa and G. Le Caër, J. Alloys Comp 536S (2012) p.S31 [4] J.M. Loureiro, B.F.O. Costa, G. Le Caër and B. Malaman, Solid State Phenom 194 (2013) p.187 [5] J.M. Loureiro, B.F.O. Costa, B. Malaman, G. Le Caër, S. Das and V.S. Amaral, J. Alloys Comp 615 (2014) p.S559 [6] N.N. Delyagin and E.N. Kornienko, Sov. Phys. Solid State 13 (1971) p.1254

NanoPT2015 ʹ February 11-13, 2015

Figures

57

Figure 1- RT Fe Mössbauer spectra of mechanically alloyed (FeCo)Snx: as-milled (left) and annealed at 673K (right)

119

Figure 2- RT Sn Mössbauer spectra of mechanically alloyed (FeCo)Snx: as-milled (left) and annealed at 673K (right)

Figure 3- RT hyperfine magnetic field 119 distributions ( Sn: 57 left, and Fe: right) of (FeCo)88Sn12 alloy, asmilled and annealed

Figure 4- Neutron diffraction patterns of (FeCo)100-xSnx (6 x 25) alloys milled during 10h and then annealed at 673K for 15h.

NanoPT2015 ʹ February 11-13, 2015

Nanofabrication of Magnetic Tunnel Junction Pillars Targeting Nano-Oscillator Applications J. D. Costa1,2, E. Paz1, J. Borme1, S. Serrano1, J. M. Teixeira2, J. Ventura2, R. Ferreira1, P. P. Freitas1,3 1 International Iberian Nanotechnology Laboratory, INL, Avenida Mestre JosĂŠ Veiga, 4715-330 Braga, PORTUGAL; 2 IN-IFIMUP, Rua do Campo Alegre 687, 4169-007 Porto, PORTUGAL; 3 INESC-MN and IN- Institute of Nanoscience and Nanotechnology, Rua Alves Redol, 9-1, 1000-029 Lisbon, PORTUGAL diogo.costa@visitor.inl.int Abstract

Magnetic Tunnel Junctions are Spintronic devices constituted by two ferromagnetic layers separated by a nanometric insulating barrier. The theoretical predictions of giant Tunnel Magnetoresistance (TMR) values in fully crystalline Fe(001)/MgO(001)/Fe(001) structures [1] were soon followed by its experimental verification [2,3]. Such giant TMR effect arises from the conservation of the coherence of the electron wave function during tunneling across crystalline MgO and from the smaller decay rate of the spin up states in the barrier when compared to that of spin down states (spin filtering effect) [4]. In state of the art CoFeB-MgO MTJs, TMR ratios of up to 600% have been reported [5]. In the low resistance x area (RA) range, which is the most important for applications, TMR values of 138% have been GHPRQVWUDWHG LQ 07-V ZLWK 5$a Č?Č?P2 (in unpatterned MTJs) [6].

These results promptly widened the prospect of fabricating novel magnetic devices that operate using spin transfer torque (STT) mechanisms. This effect consists in the transfer of the moment of magnetic spins from a polarized electrical current to the ferromagnetic layers, thus allowing the manipulation of the magnetization of nano-magnets by means of local currents in opposition to magnetic fields. Two of the best positioned STT applications to reach the commercialization in the short term are RF emitters resulting from persistent magnetic dynamics driven by DC currents and non-volatile magnetic random access memories.

In order to achieve high quality STT devices the downscaling of MTJs until dimensions below 100 nm is necessary. In this presentation we will describe our nanofabrication process which is mainly based in e-beam lithography and ion milling steps. Several problems arise from the miniaturization of the MTJs being one of the most prominent the material re-deposition on the sidewalls of the nanopillars during the ion beam etching. This re-deposition inflates the final device critical dimension. More importantly, it causes the electrical shunting across the barrier which decreases the TMR. To remove the material re-deposition a low angle milling is usually used after the normal milling definition. However, low angle millings create damages in the device edges, generate shadowing effects that prevent the formation of vertical sidewalls and decrease the process uniformity due to clamps used at wafer edges. The edge damage can be minimized by using a low beam energy milling. However, the divergence of the beam increases for lower beam energies and thus a compromise must be found. Another problem related to the nanofabrication process consists in conferring mechanical stability to the devices while keeping the nanopillars open on top. This structure enables the microfabrication of the remaining components of the device that allow the reading/writing of the MTJ. To achieve this structure a dielectric material is deposited after the nanopillar definition and afterwards opened on the top of the pillars. In order to open the MTJs, processes based on lift-off and chemical-mechanical processes (CMP) have been used. Despite the simplicity of the lift-off process, the yield of the open nanopillars is relatively low and it has a process time that can go up to two weeks. Moreover, the process is intrinsically worse for smaller nanopillars. As for the CMP process, it is a very fast process that opens more easily the smaller pillars. However, there are a lot of residues arising from the planarization and a good uniformity is difficult to achieve.

Here, we also propose the use of an ion beam planarization step after the nanopillar definition. This process is faster than the lift off and cleaner that CMP and intrinsically better for the smaller pillar sizes. Using the described process we were able to achieve MTJs with RA below 1.5 Č?Č?P2 and TMR up to 130%. We will also give a general overview of the different devices fabricated, such as the double barrier MTJs, magnetic vortexes and MTJs with perpendicular magnetic anisotropy.

References

[1] Spin-dependent tunneling conductance of Fe/MgO/Fe sandwiches, W.H. Butler, X.-G. Zhang, T.C. Schulthess, and J.M. MacLaren, Phys. Rev. B 63, 054416 (2001), [2] Giant tunnelling magnetoresistance at room temperature with MgO (100) tunnel barriers, S.S.P. Parkin, C. Kaiser, A. Panchula, P.M. Rice, B. Hughes, M. Samant, and S.-H. Yang, Nat. Mater. 3, 862 (2004), [3] Giant room-temperature magnetoresistance in single-crystal Fe/MgO/Fe magnetic tunnel junctions, S. Yuasa, T. Nagahama, A. Fukushima, Y. Suzuki, and K. Ando, Nature Mater. 3, 868 (2004), [4] Giant tunnel magnetoresistance in magnetic tunnel junctions with a crystalline MgO(0 0 1) barrier, S. Yuasa and D.D. Djayaprawira, J. Phys. D 40, R337 (2007), [5] Tunnel magnetoresistance of 604% at 300 K by suppression of Ta diffusion in CoFeB/MgO/CoFeB pseudo-spin-valves annealed at high temperature, S. Ikeda, J. Hayakawa, Y. Ashizawa, Y.M. Lee, K. Miura, H. Hasegawa, M. Tsunoda, F. Matsukura, and H. Ohno, Appl. Phys. Lett. 93, 082508 (2008).

[6] In situ heat treatment of ultrathin MgO layer for giant magnetoresistance ratio with low resistance area product in CoFeB/MgO/CoFeB magnetic tunnel junctions, S. Isogami, M. Tsunoda, K. Komagaki, K. Sunaga, Y. Uehara, M. Sato, T. Miyajima, M. Takahashi, Appl.

Phys. Lett. 93, 192109 (2008).

The role of TiO2 nanoparticles and photocatalytic processes in the treatment of industrial effluents.

J.O. Carneiro a, A. P. Samantilleke a, P. Partpot b, C Tavares a, F. Fernandes a, M. Pastor a, A. Correia a, V. Teixeira a a Department of Physics, University of Minho, Azurém Campus, 4800-058, Guimarães, Portugal b Department of Chemestry, University of Minho, Azurém Campus, 4800-058, Guimarães, Portugal

In recent years, new textile materials have been developed using nanotechnology-based tools.

These have been extensively investigated for use in various scientific and technological fields. This multidisciplinary methods of changing surface has become thus an essential step in order to combine different physical and chemical properties for obtaining a multifunctional material. The development of self-cleaning textile surfaces with combined properties has a great potential for reducing environmental impact related pollution caused by effluents and its versatility in application to any geometry.[1] [2] The release of untreated wastewater, primarily from textile industries as well as sewage in rivers and lakes stimulate serious ecosystem imbalances that, if not addressed can escalate to create conditions that threaten human health. The need for versatile materials, which reduce or minimize the effect of hazardous compounds is growing rapidly. . In this context, the photocatalytic activity of nanomaterials based on titanium dioxide (TiO 2) in textile applications has been identified as a strategic vector with a considerable industrial impact. [3] The heterogeneous photocatalysis is potentially a powerful technological tool for various applications Titanium dioxide is by far the most applied material,in photocatalitic processas due to its availability in the crust, high chemical stability, high oxidation power, low toxicity and low cost [4].

The techniques of deposition of TiO2 particles in a liquid phase have attracted considerable interest, as such matrials and technques are with low production cost and relative ease of industrial implementation. [5] The implementation and use of photocatalityc textiles in environmental remediation has a high relevance directly related with their contact area. Titanium dioxide was applied by a mechanical process called padding in this work. The textiles werefully characterized in order to investigate whether they retainthe initial properties while the surface maintaining self-cleaning abilities. The samples of textiles were subjected to hot wash tests to assessthe adhesion of nanoparticles.

References [1]

Vinu R, Madras G. Environmental remediation by photocatalysis 2010;90.

[2]

Meilert KT, Laub D, Kiwi J. Photocatalytic self-cleaning of modified cotton textiles by TiO2 clusters attached by chemical spacers. J Mol Catal A Chem 2005;237:101±8.

[3]

Dalton C. J.P. Smol, Pollution of lakes and rivers: a paleoenvironmental perspective, 2nd edition. J Paleolimnol 2009;42:301±2.

[4]

Diebold U. The surface science of titanium dioxide. Surf Sci Rep 2003;48:53±229.

[5]

Fujishima A, Zhang X. Titanium dioxide photocatalysis: present situation and future approaches. Comptes Rendus Chim 2006;9:750Âą60.

Exfoliation of graphite using pyrene and perylene derivatives 1

1

2

Eunice Cunha , M. Conceição Paiva , M. Fernanda Proença , Rui Araújo 1

2

Instituto de Polímeros e Compósitos/I3N, Universidade do Minho, Campus de Azurém, 4800-058 Guimarães, Portugal

2

Centro de Química, Universidade do Minho, Campus de Gualtar, 4710-057 Braga, Portugal eunice.cunha@dep.uminho.pt

Abstract Since the isolation of graphene by mechanical exfoliation of graphite in 2004 [1] this material has been the focus of research among the scientific community. The excellent electronic, mechanical, thermal and optical properties of graphene [2] have reveled huge potential applications in various fields such as energy storage, [3,4] composite materials [5] and sensor technology [6]. However, the production of graphene in large scale, with controlled quality and reasonable cost, is still a goal to achieve and became an important target and research topic.

The large scale graphene production processes are based on the conversion of SiC (silicon carbide) to graphene via sublimation of silicon at high temperature, chemical vapor deposition (CVD) growth, oxidation of graphite followed by exfoliation and reduction of the oxidation products, and exfoliation of graphite in organic solvents with high surface tension. These methods lead to large scale production, but present some disadvantages namely the high cost, or the production of graphene with structural defects or contaminants which are difficult to remove. [7] Some aromatic compounds such as pyrene and perylene derivatives, functionalized to render them amphiphilic, have been reported to effectively stabilize carbon nanotubes in aqueous suspensions. [8,9] Recently, the production of graphene based on graphite exfoliation through non-covalent interactions between graphene/pyrene and graphene/perylene derivatives was also reported.[10] This approach promotes the exfoliation and stabilization of graphene in water, leading to the production of few- and single- layer graphene without damaging its structure.

The present work reports the preparation of stable aqueous suspensions of few-layer graphene using low concentration solutions of pyrene and perylene derivatives. The suspensions were analyzed by UVVisible spectroscopy. The graphene-based materials deposited on surfaces were analyzed by Raman spectroscopy, showing the effectiveness of the exfoliation of pristine graphite. TEM images of the suspensions illustrate the formation of few layer graphene. Figure 1a presents the Raman spectra of graphite and few-layer graphene obtained by exfoliation with a pyrene derivative (Py-XGnP), and Figure 1b illustrates the TEM observation of the Py-XGnP. Acknowledgement We gratefully acknowledge FCT for PhD grant SFRH/BD/87214/2012 and Post-doc grant SFRH/BPD/88920/2012.

References [1] K. Novoselov, A. Geim, S. Morozov, D. Jiang, Y. Zhang, S. Dubonos, I. Grigorieva and A. Firsov, Science, 306 (2004) 666-669.

[2] A. Geim and K. Novoselov, Nature Materials, 6 (2007) 183-191.

[3] M. Stoller, S. Park, Y. Zhu, J. An and R. Ruoff, Nano Letters, 8 (2008) 3498-3502 [4] S. Ghosh, X. An, R. Shah, D. Rawat, B. Dave, S. Kar, S.Talapatra, Physical Chemistry C, 116 (2012) 20688í20693.

[5] H. Kim, A. Abdala and C. Macosko, Macromolecules, 43 (2010) 6515±6530.

[6] X. Zhang, F. Gao, X. Cai, M. Zheng, F. Gao, S. Jiang and Q. Wang, Materials Science and Engineering C, 33 (2013) 3851±3857.

[7] V. Singh, D. Joung, L. Zhai, S. Das, S. Khondaker and S. Seal, Progress in Materials Science, 56 (2011) 1178±1271.

[8] T. Fujigaya and N. Nakashima, Polymer Journal, 40 (2008) 577±589.

[9] R. Araújo, C. Silva, M. C. Paiva, M. Melle Franco and M. F. Proença, RSC Advances, 3 (2013) 24535-24542.

[10] D. Parviz, S. Das, H. Ahmed, F. Irin, S. Bhattacharia, and M. Green, ACS Nano, 6 (2012) 8857± 8867

Intensity (a.u.)

a)

Py Âą XGnP XGnP

1000

1500

2000

2500

3000

-1

Raman Shift (cm )

b)

Figure 1: a) Raman spectra of pristine graphite (XGnP) and exfoliated graphite using pyrene derivative (Py-XGnP); b) TEM image of Py-XGnP (on the left), magnified TEM Image (on the right) and XRD pattern of magnified Py-XGnP TEM image.

Nanocomposite materials for shaping the diffusive transport of light a

b

a

André Espinha, María Concepción Serrano, Álvaro Blanco, Cefe López

a

a

Instituto de Ciencia de Materiales de Madrid (ICMM-CSIC), Calle Sor Juana Inés de la Cruz, 3, Cantoblanco, 28049 Madrid, Spain b Hospital Nacional de Parapléjicos, Finca de la Peraleda, s/n, 45071 Toledo, Spain acmespinha@icmm.csic.es Abstract In the photonics community, disordered materials are being explored more and more due to their particular way to interact with light [1]. Typically, they are composed of non-absorbing building blocks with sub-micrometric size, distributed in a random way. As so, their refractive index is a complex function of position and light undergoes multiple scattering [2] thus, the transport is diffusive. If the scattering efficiency is equal for the whole visible electromagnetic spectrum, they present a white, milky aspect.

Not only they are very rich systems which exhibit challenging phenomena for physical interpretation, but also several research areas with social impact and industrial potential have emerged, ranging from random lasers to imaging through opaque media, for example.

Nanocomposites, formed by an optically functional phase embedded in a processable matrix, are a very versatile platform for developing optical applications [3] and, in this way, may be used for producing diffusive systems.

We would like to present our latest achievements in the field, which have been aimed at engineering the transport of light (specifically the transport mean free path) in nanocomposites based on multifunctional polymers presenting shape memory effect [4]. Different parameters such as the concentration of scatters or the temperature could be acted on in order to design materials which are almost transparent or, on the contrary, highly opaque.

We believe that our results might pave the way for more systematic investigations with potential impact on intelligent light sources with improved energy efficiency or new kinds of actuators.

This work was partially supported by EU FP7 NoE Nanophotonics4Energy grant No. 248855, the Spanish MICINN project MAT2012±31659 (SAMAP), and Comunidad de Madrid S2009/MAT-1756 (PHAMA) program. A.E. was supported by the FPI Ph.D. program from the MICINN. M.C.S. acknowledges Instituto de Salud Carlos III - MINECO for a Miguel Servet contract (CP13-00060).

References [1] D. S. Wiersma, Nature Photonics, 7 (2013) 188.

[2] B. Van Der Mark, M. P. Van Albada, A. Lagendijk, Physical Review B, 37 (1988) 3575.

[3] L. Beecroft, C. Ober, Chemistry of Materials, 9 (1997) 1302.

[4] M. Behl, M. Razzaq, A. Lendlein, Advanced Materials, 22 (2010) 3388.

Synthesis and optical properties of CdSe nanoparticles in PVK semiconducting polymer J.C. Ferrer, S. Fernández de Ávila, J.L. Alonso Área de Electrónica, Universidad Miguel Hernández, Av. Universidad, s/n, Elche (Spain) jc.ferrer@umh.es Abstract Semiconducting nanocrystals, or quantum dots, exhibit interesting properties like size-dependent photoemission wavelength over a wide spectral range and high photoluminescence quantum yields [1].

Blends of polymer solutions and nanocrystals in colloidal suspension are very attractive from the point of view of device fabrication since the resulting nanocomposite material combines the optical properties and robustness of inorganic particles with the ease of processing and flexibility of polymers [2,3].

Poly(N-vinylcarbazole) (PVK) is a hole transport polymer exhibiting an emission spectrum that, owing to the properties of carbazole groups, covers the entire blue region. CdSe is an II-VI semiconductor with a 1.74 eV bandgap which is suitable for integration in optoelectronic devices operating in the visible wavelength range.

Based on the method reported in [4] we have performed the synthesis of CdSe nanocrystals capped with Fluorothiophenol (ShPhF) LQWURGXFLQJ VHYHUDO YDULDWLRQV LQ WKH SURFHGXUH ȝO RI 6+3K) ZHUe dissolved in 10 ml of methanol and 308 mg of Cd(NO 3)2Â +2O were dissolved in 2 ml of water and 8 ml of methanol. The Cd(NO3)2 solution was added to the SHPhF solution resulting in a white precipitate according to the following reaction: Cd (NO3)2 HS

F

F

S

Cd

S

F

The precipitate was washed with methanol and centrifuged three times. The washed precipitate was vacuum dried and the resulting powder was analyzed by X-ray photoelectron spectroscopy with a Phi 5500 ESCA system, which confirmed the chemical composition of the powder. The Cd(FC6H5S)2 complex contains both the cadmium atoms for the subsequent CdS synthesis and the organic molecule for the capping.

52 mg of the Cd(FC6H5S)2 powder was dissolved in 20 ml of dimethyl sulfoxide (DMSO) and 0.1 ml of a elemental Se 0.1% solution in toluene were added to the Cd(FC6H4S)2 resulting in an optically clear yellow solution indicating the formation of CdSe quantum dots. Bright yellow fluorescence of this VROXWLRQ FRXOG EH REVHUYHG XQGHU 89 OLJKW Ȝ QP LOOXPLQDWLRQ 7KH QDQRFU\VWDOV remained stable during months showing no change in luminescence intensity and wavelength. The synthesis of the CdS nanocrystals using the Cd(FC6H4S)2 complex has a major advantage compared to other cadmium salts: the molecule contains both the cadmium atoms and the organic radical for the capping leaving no residual after reaction with elemental selenium.

Three blends of CdSe quantum dots and PVK 0.3% in toluene were obtained by mixing different volumes of the respective solutions according to the following proportions: 25% vol. PVK : 75% vol.

CdSe, 50% vol. PVK : 50% CdSe and 75% vol. PVK : 25% vol. CdSe (samples 1:3, 1:1, 3:1 respectively). An aliquot of the starting CdSe nanocrystal and PVK solutions were kept for reference purposes (samples 0:1 and 1:0 respectively).

Transmission electron microscopy (TEM) images were obtained with a Philips CM30 microscope operating at 300 kV. The absorbance spectra were recorded with a Shimadzu UV-1603 spectrometer.

TEM images of the quantum dots prior to the mixing with the polymer were obtained in order to determine the size and the quality of the nanoparticles. The images show isolated nanoparticles with an average size about 4 nm. Since the Bohr radius of CdSe is about 5 nm [1], we expect to observe the effects of the quantum confinement in the optical characterization measurements. Photoluminescence (PL) spectra were obtained by means of a Photon Technology International fluorimeter.

The optical absorption of the nanocomposite solution as well as the reference samples is presented in fig. 1. The spectrum of the pure quantum dot solution (sample 0:1) shows an excitonic peak at an HQHUJ\ ( H9 Ȝ QP ZKLFK LV IDU IURP WKH EDQGJDS HQHUJ\ RI EXON &G6H H9 7KLV VKLIW indicates that strong quantum confinement has been achieved, as expected from the TEM observations.

The absorption spectrum of the bare PVK solution (sample 4:0), depicted in the same figure, shows an DEVRUSWLRQ HGJH ORFDWHG DW H9 ศ QP 7KH VSHFWUD RI WKH EOHQGV RI WKH WZR VROXWLRQV VKRZ DQ increasing absorbance of the excitonic peak related to the quantum dots as the amount of CdSe is increased (samples 1:3, 2:2, 3:1).

Photoluminescence (PL) measurements of the reference samples and blends were performed using an excitation wavelength at 370 nm. The recorded spectra are presented in fig.3. The luminescence spectrum of the pure PVK solution (sample 4:0) is dominated by a peak located at 3.1 eV (400 nm) while the pure quantum dot solution sample (0:4) shows a broad peak found at 2.42 eV (513nm). The PL spectra of the blends display the characteristics of the emission from the two species. Note that although the PVK intensity decreases gradually as the PVK amount is reduced, the intensity change of the CdSe peak is weaker compared to that of PVK. This observation could be related to a Fรถrster-type energy transfer from PVK to CdSe [5]. This kind of energy transfer requires an overlap between the emission spectrum of donor and the absorption spectrum of the acceptor. In our case, the overlap is evident since the PL peak of the polymer is located at 3.1 eV and the excitonic peak of the nanocrystals has a maximum at 3.06eV. Thus, this diluted nanocomposite shows the potential to be used as active layer for optoelectronic devices.

References [1] A.D. Yoffe, Adv. Phys., 50, (2001) 1.

[2] W. Caseri, Macromol. Rapid Commun., 21, (2000) 705.

[3] E. Holder, N. Tessler and A.L. Rogach, J. Mater. Chem.,18 (2008), 1064.

[4] I.G. Dance, A. Choy and M.L. Scudder, J. Am. Chem. Soc.. 106 (1984) 6285.

[5] F. Teng, A. Tang, B. Feng and Z. Lou, Appl. Surf. Sci., 254 (2008) 6341.

Figures

Fig. 1. Optical absorption spectra of pure CdSe nanocrystal (0:4), pure PVK (4:0) and blends of 25% PVK:75% CdSe (1:3), 50% PVK:50% CdSe (1:1) and 75% PVK:25% CdSe (3:1).

Fig. 2. PL spectra of pure CdSe nanocrystal (0:4), pure PVK (4:0) and blends of 25% PVK:75% CdSe (1:3), 50% PVK:50% CdSe (1:1) and 75% PVK:25% CdSe (3:1).

Modification of optical properties of polymer films by addition of PbS nanoparticles S. Fernández de Ávila, J.C. Ferrer, J.L.Alonso and B. Rakkaa Departamento de Ingeniería de Comunicaciones, Universidad Miguel Hernández, Edificio Innova, Avda. de la Universidad s/n, Elche, 03202 Alicante, Spain s.fdezavila@umh.es Abstract Semiconductor nanoparticles have attracted the interest of many research groups for the last two decades. As the diameter of a semiconductor crystal approaches its exciton Bohr diameter, the electronic properties of the semiconductor start to change. This is known as the quantum size effect. It is commonly observed that as the particle size decreases the optical absorption edge shifts to higher energy (blue-shift) [1].

By doping organic materials with these nanoparticles a variety of nanocomposite materials can be prepared with customizable optical and electrical properties. These nanocomposites are especially interesting if they can be easily synthesized and processed at low cost. In particular, those composites processed from solution that can be cast by simple techniques, such as different printing technologies, drop-casting or spin-coating among others.

Polymers have proved to be a useful matrix in assembling the nanoparticles, improving their stability and helping to control the size of the semiconductor nanoparticles [2].

In this study we use the well known poly[2-methoxy-5-(3’,7’-dimethyloctyloxy)-1,4-phenylenevinylene] (MDMO-PPV) semiconducting polymer as matrix, and we will synthesize lead sulfide (PbS) nanoparticles (NPs) directly in it by using a very simple synthetic route.

Assuming that optical properties of semiconductor nanoparticles can also be modified by surface chemical modification, 1,4-fluorothiophenol (SHC6H4F) was always used to cap the NPs for the experiment reported here.

Pb(SPhF)2 complex is prepared by reaction of Pb(NO3)2 and SHC6H4F. This complex contains the Pb and the capping radical for the PbS NPs, and it is soluble in dimethylsulfoxide (DMSO). Addition of a small volume of sulfur to this precursor solution produced PbS NPs capped with the organic radical.

This reaction is shown in figure 1 [3].

To prepare the nanocomposite a whole batch of solutions containing MDMO-PPV and Pb(SPhF)2 complex were dissolved using 4:1 toluene:DMSO solvents ratio. PbS nanoparticles are synthesized by adding a solution of sulfur in toluene to the polymer-complex solution. Changing the volume of sulfur added to each solution the amount of PbS nanoparticles synthesized inside the polymer can be modified.

The presence of these PbS NPs has been checked by TEM measurements as can be seen in figure 2.

Optical properties of thin films prepared by spin casting from nanocomposite solutions with increasing PbS NPs loading, have been studied.

Quenching of PL emission is observed when the ratio of PbS NPs increases with respect to the polymer suggesting the occurrence of Dexter energy transfer from the polymer to the PbS NPs. An enhancement of optical absorption is found for nanocomposites with increasing PbS NPs concentration [4]. Optical absorption is markedly increased for nanocomposite films compared to pure polymer film suggesting its potential application in optoelectronic devices such as solar cells.

We demonstrate that optical properties of MDMO-PPV polymer film can be modified by addition of PbS nanoparticles.

References [1] Y. Wang, A. Suna, W. Mahler, and R. Kasowski, The Journal of Chemical Physics, vol. 87, no. 12 (1987) 7315.

[2] S. Kango, S. Kalia, A. Celli, J. Njuguna, Y. Habibi, and R. Kumar, Progress in Polymer Science, vol.

38, no. 8 (2013) 1232.

[3] J. C. Ferrer, A. Salinas-Castillo, J. L. Alonso, S. Fernández de Avila, and R. Mallavia, Materials Chemistry and Physics, vol. 122 (2010) 459.

[4] S. Fernández de Ávila, J.C. Ferrer, J.L. Alonso, R. Mallavia and B. Rakkaa. Journal of Nanomaterials Volume 2014, Article ID 671670 (2014) 1-7.

Figures

Figure 1: PbS nanoparticles capped with 1,4-fluorothiophenol (SHC6H4F) can be obtained by reaction of Pb(SPhF)2 complex with a small amount of sulphur.

Figure 2: TEM image of an ensemble of PbS NPs within the polymer matrix

Optimization and characterization of lipid-based nanoparticles for topical therapy of psoriasis Mara Ferreira1,2, Sofia A. Costa Lima1, Salette Reis1 1REQUIMTE/

Department of Chemistry, Faculty of Pharmacy, University of Porto,Rua de Jorge Viterbo Viterbo Ferreira, n.º228, 4050-313, Porto, Portugal 2Faculty of Engineering of University of Porto, Rua Dr. Roberto Frias, s/n 4200-465, Porto, Portugal maraapferreira@hotmail.com, slima@ff.up.pt

Abstract Psoriasis is a common chronic, autoimmune and systemic inflammatory disease of the skin and joints and occurs in 2±3% of the population. It is characterized by well-demarcated thick erythematous plaques, red and scaly skin which most commonly appears on the elbows, knees, scalp and umbilicus area. Psoriasis is affected by genetic and environmental factors and is associated with co-morbidities counting: loss of quality of life, cardiovascular disease, among others [1±3]. The most important emerging treatments include topical treatments, phototherapy, systemic therapies and biological therapies, employed depending on the severity of the disease [4].

Lipid based carriers could be classified into particulate carriers and this type include solid lipid nanoparticles (SLNs) and nanostructured lipid nanoparticles (NLCs). In particular, NLCs consist of a mixture of solid and liquid lipids that produce nanosized carriers that interact better with skin cells making them very useful for improvement in dermal therapy. In this work, methotrexate was the drug selected for incorporation in the lipid-based nanoparticles as it is the 'gold standard in managing psoriasis' and has the ability to block certain enzymes which are involved in the autoimmune system [4].

The first step of this study was the optimization of some parameters for better development of NLCs in the following main criteria: average particle size between 200-300 nm and encapsulation efficiency of drug higher than 75%.

MTX-loaded NLCs were successfully prepared by hot emulsification/ high-shear homogenization using Witepsol E85 and lipid mygliol 812 as lipidic core and poly vinyl alcohol as surfactant. For this combination a 27-run, 3-factor, 3-level Box±Behnken design was employed to optimize the process according amount of surfactant, amount of drug and amount of liquid lipid. The characterization was conducted according to their physico-chemical properties such as: particle size, polydispersity index, surface potential and encapsulation efficiency. Size and polydispersity index are evaluated by dynamic light scattering and surface potential throughout a laser Doppler electrophoresis. For the encapsulation efficiency the concentration of non-incorporated MTX was determined by absorption spectroscopy..

The optimized nanoparticles were compared with another type of lipid nanoparticles, the SLNs, to identify the best carrier for MTX for this pathology.

The results of the current study warrant further exploration for the use of drug loaded NLCs as a controlled delivery system for topical therapy of psoriasis.

Acknowledgments: This work received financial support from the European Union (FEDER funds through COMPETE) and National Funds (FCT) through project Pest-C/EQB/LA0006/2013. This work was also unded by ON.2 QREN - Quadro de Referência Estratégico Nacional ± QREN, by FEDER funds through the Programa Operacional Factores de Competitividade ± COMPETE and national funds throught FCT through project NORTE-07-0124-FEDER-000067. The authors would like to acknowledge Excella for kindly provide the MTX.

References [1] G. K. Perera, P. Di MeglLR DQG ) 2 1HVWOH Âł3VRULDVLV ´ Annu. Rev. Pathol., vol. 7, (2012) pp. 385Âą422, [2] M. a Lowes, M. SuĂĄrez-)DULxDV DQG - * .UXHJHU Âł,PPXQRORJ\ RI SVRULDVLV ´ Annu. Rev. Immunol., vol. 32, (2014) pp. 227Âą55, [3] J. Berth--RQHV Âł3VRULDVLV ´ Medicine (Baltimore)., vol. 41, (2013) no. 6, pp. 334Âą340 [4] ' 3UHVV Âł8SGDWH RI WKH PDQDJHPHQW RI FKURQLF SVRULDVLVŕŻ&#x2014; QHZ DSSURDFKHV DQG HPHUJLQJ WUHDWPHQW RSWLRQV ´ (2010) pp. 25Âą37

Cellulose nanofibres obtained by TEMPO mediated oxidation and mechanical treatment: effect of the mechanical treatment Jorge F. Pedrosa, Tiago F. Nunes, Ana F. Lourenço, JosÊ A. Gamelas, Paulo J. Ferreira

*

CIEPQPF, Department of Chemical Engineering, University of Coimbra, PĂłlo II, R. SĂ­lvio Lima, P-3030 790 Coimbra, Portugal

*paulo@eq.uc.pt

Abstract The size and size distribution of nanofibres is always an important parameter to consider, but it should be mentioned that presently no standard methods or validated techniques are available for the size evaluation of polydisperse nanomaterials with a high aspect ratio [1].

In the present work, four samples of cellulose nanofibers were produced from an eucalypt kraft pulp pretreated with 15 mmol of NaClO per gram of cellulose and catalytic amounts of TEMPO (2,2,6,6tetramethylpiperidine-1-oxyl radical) and NaBr, according to the methodology described by Saito et al.

[2]. After the chemical treatment the fibers were subjected to different mechanical treatment intensities during homogenization.

Three samples were obtained after passing through the homogeneizer one time (at 500 bar) (1P15R), two times (one at 500 bar and one at 1000 bar) (2P15R) and four times (one at 500 bar and three at 1000 bar) (4P15R). In addition, for control, one sample was left without any mechanical treatment (0P15R).

The samples were then characterized in terms of yield of nanofibres production assessed by centrifugation, transmittance of the suspensions in the 400-800 nm visible range (Fig.1), concentration of carboxylic groups determined by conductimetric titration and zeta potential. The size distribution of the material was evaluated by laser diffraction spectroscopy and by dynamic light scattering (Fig.3) of the cellulose nanofibres suspensions (Fig. 2 and 3 respectively). Generally it was concluded that the homogeneization highly increases the amount of nanofibrils but no significant further effects, both in terms of yield and size, are detected with more extensive mechanical treatment.

References [1] Fraschini, C., Chauve, G., Le Berre, J-) (OOLV 6 0pWKRW 0 2Âś &RQQRU % DQG %RXFKDUG J. Nordic Pulp and Paper Research Journal, 29 (2014) 31-40.

[2] Saito, T., Kimura, S., Nishiyama, Y., Isogai, A., Biomacromolecules, 8 (2007) 2485-2491.

Figures

Fig.1- Visible spectra in the transmittance mode.

Fig.2- Volume distributions obtained by laser diffraction spectroscopy.

Fig.3- Intensity distributions obtained by dynamic light scattering.

Characterization of genomic SNP via colorimetric detection using a single gold nanoprobe 1,2

2

1

1

Fábio Ferreira Carlos , Orfeu Flores , Gonçalo Doria , Pedro Viana Baptista CIGMH, Department of Life Sciences, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Campus de Caparica, Caparica, Portugal 2 STABVIDA, Investigação e Serviços em Ciências Biológicas, Lda. Madan Parque, Caparica, Portugal fa.carlos@campus.fct.unl.pt 1

Abstract Identification of specific nucleic acid sequences mediated by gold nanoparticles derivatized thiolmodified oligonucleotides (Au-nanoprobes) has been proven a useful tool in molecular diagnostics [1,35]. Here, we demonstrate that, upon molecular optimization, detection may be simplified and results attained using a single Au-nanoprobe to detect SNP in homo- or heterozygous condition (Figure 1). Aunanoprobes are becoming extremely useful tools for routine molecular diagnostics involving single-base mismatch detection that can be a fast, cheap and reliable alternative to standard techniques [4].

We demonstrate the robustness of this approach through validation using clinical samples and screening for the SNP rs9939609 in the FTO gene locus [2]. For the first time, we demonstrate that, upon comprehensive optimization, a single Au-nanoprobe may be used alone to detect SNP by presenting distinct threshold for each genetic status (wild type, heterozygous and mutant) with high degree of sensitivity (87.50%) specificity (91.67%) [5].

Results were validated using Sanger sequencing as gold standard. Sensitivity, specificity and limit of detection (LOD) were determined and statistical differences calculated by one-way analysis of variance $129$ DQG D SRVW KRF 7XNH\¶V WHVW WR DVFHrtain whether there were any differences between Aunanoprobe genotyped groups. From the 20 samples genotyped via Sanger sequencing, 8 samples were wild type (T/T), 7 samples heterozygous (T/A) and 5 samples mutated (A/A) [4]. Genotyping using the Au-nanoprobe determined 9 wild type (T/T) samples, 7 heterozygous (T/A) and 4 mutated (A/A). The -1 LOD for Au-nanoprobe FTOwt20 was set at 20 µg ml .This simple and fast approach requires low complexity apparatus (UV/Vis spectroscopy) but may also been evaluated by the naked eye.

References [1] Baptista P, Pereira E, Eaton P, Doria G, Miranda A, Gomes I, et al, Anal. Bioanal. Chem., 391 2008 943-50 [2] Carlos FF, Silva-Nunes J, Flores O, Brito M, Doria G, Veiga L et al, Diabetes Metab. Syndr. Obes., 11(6) 2013 241-5.

[3] Doria G, Franco R, Baptista P, IET Nanobiotechnol., 1(4) 2007 53-7.

[4] Doria G, Conde J, Veigas B, Giestas L, Almeida C, Assunção M, Rosa J, Baptista PV, Sensors, 12(2) 2012 1657-1687.

[5] Carlos FF, Flores O, Doria G, Baptista PV, Anal. Biochem., 465C 2014 1-5.

Figures

Figure 1 ± %ORRG VDPSOH ZDV FROOHFWHG IURP ILQJHU SULFN XVLQJ D ODQFHW DQG VWRUHG LQ )7$ ,QGLFDWHG Micro Card (Whatman, UK). DNA extraction was carried out for subsequently PCR reactions. After PCR reaction, Au-nanoprobe was mixed with PCR products and a hybridization step was carried out i) after salt addition in the presence of a non-complementary or unrelated PCR a colorimetric change is visible from red to purple after a certain time, ii) after salt addition in the presence of a fully complementary PCR product no colorimetric change is visible and the solution remains red. This color observation can also be observed by UV/Vis spectroscopy.

Simultaneous Delivery of Drugs and Genes by Multi-block Polymeric Nanomicelles for Synergistic Cancer Therapy Vítor M. Gaspar1, Cristine Gonçalves2, Duarte Melo-Diogo1, Elisabete C. Costa1, João A. Queiroz1, Chantal Pichon2, Fani Sousa1 and Ilídio J. Correia1 1CICS-UBI

± Health Sciences Research Center, University of Beira Interior, 6200-506, Covilhã, Portugal de Biophysique Moléculaire, CNRS UPR4301, Inserm and University of Orléans, 45071 Orléans cedex 02, France

2Centre

vm.gaspar@fcsaude.ubi.pt Abstract Presently cancer remains one of the most predominant incurable diseases and it is estimated that its worldwide incidence will continue to increase in the future [1]. From a clinical perspective chemotherapy is one of the best established methodologies for cancer treatment, being generally applied either as first line therapy for early stage disease, or palliative care in later phases. However, the administration of anti-tumoral drugs generally induces systemic cytotoxicity due to their poor selectivity to target cancer cells and tissue partition. Moreover, cancer drug resistance following a multi-stage treatment regime is common and this phenomenon further contributes to the ineffectiveness of chemotherapy. In this context the simultaneous delivery of different anti-tumoral drugs or drug-nucleic acid combinations arises as an exceptionally promising strategy for improving treatment efficacy and overcome cancer drug resistance [2]. Nonetheless, combinatorial therapy is remarkably challenging since nucleic acids are readily degraded in circulation and the simultaneous administration of multiple drugs provokes intolerable cytotoxicity.

The use of polymeric micelles is a valuable option to overcome such problems since these nanosized carriers can increase the bioavailability of bioactive molecules, i.e., drugs and genes, in the tumor site by the enhanced permeability and retention (EPR) effect. This characteristic contributes for reducing systemic cytotoxicity and improves treatment efficacy. Also, due to micelles unique hydrophobichydrophilic character which self-assembles into a core-shell structure, they can be used as a reservoir for encapsulating hydrophobic anti-tumoral drugs. In turn, this encapsulation promotes a sustained release during an extended time frame and increases intracellular drug concentration. These two parameters contribute for an enhanced therapeutic effect in comparison to standard chemotherapy.

Including drug gene combinations is significantly more challenging as the physicochemical nature of these distinct bioactive molecules demands a multi-block co-polymer with both hydrophobic and cationic properties so as to encapsulate drugs and complex DNA at the same time [2]. Thus for co-delivering drugs and nucleic acids the micelles must be self-assembled from polymeric nanomaterials in which the building blocks ought to be specifically tailored to have these properties.

Herein we provide, a brief focus on the different biocompatible and biodegradable polymers for micelles self-assembly will be provided. The use of biocompatible micelles for co-delivery of anti-tumoral compounds for cancer therapy will presented. Also, a particular emphasis will be given in the synthesis of innovative tri-block copolymers for gene-drug co-delivery (Figure 1) [3]. The application of this system for the delivery of Doxorubicin and Minicircular DNA (mcDNA) will be presented and the evaluation of its biological performance in vitro and in vivo will be provided.

References [1] Rebecca Siegel, Jiemin Ma, Zhaohui Zou and Ahmedin Jemal, CA: A Cancer Journal for Clinitians, 64(1), (2014), 9-29.

[2] Vítor M. Gaspar, Cristine Gonçalves, Duarte Melo-Diogo, Elisabete C. Costa, João A. Queiroz, Chantal Pichon, Fani Sousa and Ilídio Correia, Journal of Controlled Release, 189 (2014), 90-104.

Figures

Figure 1. Schematics of gene-drug (minicircle DNA-Doxorubicin) co-delivery concept using multi-block co-polymer micellar carriers.

Strongly anisotropic wetting on highly-uniform self-similar molybdenum nanogrooves 1,*

2

2

3

4

2

Iaroslav Gnilitskyi , Ihor Pavlov , Serim Ilday , Alberto Rota , Massimo Messori , Seydi Yavas , Leonardo 1 2,5 Orazi and F. Ă&#x2013;mer Ilday 1 - DISMI - Department of Sciences and Methods for Engineering, University of Modena and Reggio Emilia, 42100, Reggio Emilia, Italy 2 - Department of Physics, Bilkent University, 06800 Ankara, Turkey 3 - Department of Physics, Computer Science and Mathematics, University of Modena and Reggio Emilia, 41125, Modena, Italy 4 - 'HSDUWPHQW RI (QJLQHHULQJ Âł(Q]R )HUUDUL´ 0RGHQD ,WDO\ 5 - Department of Eleckrical and Electronics Engineering, Bilkent University, 06800, Ankara, Turkey *Corresponding Author e-mail: iaroslav.gnilitskyi@unimore.it,

Nanostructure formation through surface treatment is mostly performed with well-established techniques including lithography and laser-induced periodic surface structuring (LIPSS). However, these techniques suffer either from the limited flexibility, high-cost, complex equipment, or suffer from the low-speed, problems of material control, and lack of uniformity and repeatability over large areas. Recently, a technique called Nonlinear Laser Lithography (NLL) was introduced, which allows fabrication of extremely uniform nanostructures, with excellent long-range repeatability and at high-speeds [1]. NLL can be applied to a variety of materials, including non-planar, even flexible surfaces. While NLL generates essentially LIPPStype of nanostructures, it does so by utilizing nonlinear feedback mechanisms arising from the interaction of femtosecond laser pulses with the target surface, as well as from the laser-initiated chemical reaction. Key features, such as superior uniformity and ability to process non-flat surfaces are a direct consequence of the self-regulation provided by these feedback mechanisms.

Applications of surface-treated nanostructures have been demonstrated in various fields including electronics, optoelectronics, photovoltaics. Although the outcomes are encouraging, because of the problems of material and process control, they are still not suitable for transfer to industrial applications. It is appears that these problems can be overcome by NLL-induced nanostructures, thanks to their aforementioned superior features, with potential for substantial impact in these and related fields. However, the technique is new and its potential for these applications needs to be evaluated systematically.

Here, we report on highly uniform, anisotropic, periodic molybdenum nanogrooves fabricated through NLL (Figure 1). We investigate the wettability characteristics of the nanogrooves as a strong candidate to be used for applications where anisotropic wetting of the surfaces is favored, ranging from microfluidics to energy applications to biomedical research such as gas seal conditions, self-cleaning surfaces, directional syringes, microprocessor cooling, high-efficiency hydropower turbines, and nanoscale digital fluidics. Wettability is investigated through contact angle measurements, where sessile drop methodology is used with distilleddeionized water as the test liquid. It is shown that the nanogrooves improved the hydrophilic behavior of the flat molybdenum surface significantly. Moreover, better wetting of the surface along the nanogrooves is observed. It is also shown that we can tune the wettability behavior, where the transition from Wenzel to Cassie regime is observed.

> @ % 2NWHP , 3DYORY 6 ,OGD\ + .DOD\Fร RJOX $ 5\EDN 6 <DYDV 0 (UGRJDQ & F. O. Ilday, Nat. Photonics 7 (2013) 897.

2

Fig. 1. SEM images of the Molybdenum surface ablated by fs-laser pulses at fluence of 0.7 J/cm . (a) Nanotextured sample at a 100 mm/s scan speed.(b) Higher magnification image, (c and d) represent higher magnification image of (a), tilted on 45ยบ of (a).(e, f) shows the 2D FFT and 1D FFT images of the micrograph (b).

Malaria Diagnostics based on Anti- Plasmodium falciparum HRPII Antibody-Functionalized Gold Nanoparticles Inês Gomes1,2, Eulália Pereira3, Nuno C. Santos1, Maria M. Mota1, Miguel Prudêncio1, Ricardo Franco2 1Instituto

de Medicina Molecular, Faculdade de Medicina da Universidade de Lisboa, 1649-028 Lisboa, Portugal.

2REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal.

3REQUIMTE, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, 4169-007 Porto, Portugal. ines.gomes@fct.unl.pt

Malaria is a significant health problem in many parts of the world, with an estimated 207 million cases and 627 000 deaths in 2012 mostly among African children.

Malaria is caused by five species of parasites in the genus Plasmodium, of which P.falciparum (Pf) is the most prevalent and deadly [1].

Rapid Diagnostic Tests (RDTs) using gold nanoparticles (AuNPs) are alternatives to conventional microscopy-based methods for malaria diagnostics.

RDTs are intended to have high reproducibility, acceptable high sensitivity and specificity, rapidity, ease of performance and interpretation, all at an affordable price.

AuNPs are ideal candidates for these tests due to their unique nanoscale properties, such as high surface areas, robustness, facile synthesis and functionalization and strong optical absorptions [2].

In this work, gold nanoparticles are functionalized with mercaptoundecanoic acid (MUA) or CALNN pentapeptide. CALNN includes a thiol group (from C) for binding to AuNPs, a hydrophobic region (AL) to promote self-assembly at the AuNP surface, and two uncharged hydrophilic asparagine residues (NN) to interact with an antibody [3]. These functionalized AuNPs are further conjugated with an anti-PfHRPII monoclonal antibody.

Conjugation of the monoclonal antibody with the functionalized AuNPs was performed either by electrostatic interactions or by covalent attachment, using the cross-linking agents EDC/NHS. The robustness and binding properties of the bionanoconjugates were evaluated by agarose gel electrophoresis and zeta potential measurements. Results showed the formation of more compact bionanoconjugates in the presence of CALNN and EDC/NHS agents. Increasing concentrations of the antigen were incubated with the bionanoconjugates for two hours. The agarose gel electrophoresis of these antigen-bionanoconjugates showed that electrophoretic mobility decreases with increasing antigen concentrations. These results indicated that it is possible to detect the PfHRPII antigen up to a concentration of 700 µg.mL-1 (Figure 1), opening up the possibility of implementing a simple agarose gel-based method for malaria antigen detection.

This new immunoassay will be developed to detect the antigen in malaria-infected in vitro blood cultures.

These bionanoconjugates are also being used in the development of a RDT on a nitrocellulose strip or on filter paper, using a competitive assay format. In this assay, the PfHRPII antigen is coated on the test zone of the dipstick, capturing the AuNP-antibody conjugate and allowing the red colour to concentrate and form a spot. This study will constitute an important proof-of-concept for future tests in clinical samples.

References [1] WHO, World Health Organization, World Malaria Report 2013.

[2] Peixoto de Almeida, M.; Pereira, E.; Baptista, P.; Gomes, I.; Figueiredo, S.; Soares, L.; Franco, R. ³*ROG 1DQRSDUWLFOHV DV %LR &KHPLFDO 6HQVRUV´, Gold Nanoparticles in Analytical Chemistry, Comprehensive Analytical Chemistry, volume 66, Elsevier, 2014, 530-560.

[3] Lévy, R.; Thanh, K. T. N.; Doty, C. R.; Hussain, I.; Nichols, J. R.; Schiffrin, J. D.; Brust, M.; Ferning, G. D. J. Am. Chem Soc., 126, 2004, 10076-10084.

Figures

A B [PfHRPII] / [AuNP-CALNN-anti-HRPII]

Figure 1 Âą A. Agarose gel electrophoresis of AuNP-CALNN-anti-HRPII-PfHRPII, using cross-linking agents EDC/NHS. B. Electrophoretic mobility vs. PfHRPII concentration.

1DQRFRDWLQJV IRU FRUURVLRQ SURWHFWLRQ RI WLWDQLXP DOOR\V

0DUFLQ *UREHOQ\ 0DáJRU]DWD .DOLV]

0RWRU 7UDQVSRUW ,QVWLWXWH -DJLHOORQVND :DUVDZ 3RODQG PDUFLQ JUREHOQ\#LWV ZDZ SO 7KH SK\VLFDO FKHPLFDO DQG PHFKDQLFDO SURSHUWLHV RI WLWDQLXP DOOR\V PDNH WKLV PDWHULDOV DQ

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´,Q*UDI7L´ *5$) 7(&+ 1&%5 LQ WKH IUDPHZRUN RI WKH 1DWLRQDO &HQWUH IRU 5HVHDUFK DQG 'HYHORSPHQW *UDI 7HFK 3URJUDPPH

5HIHUHQFHV

> @ - $ +XQW 0 6WRLFKHW &XUU 2SLQ 6ROLG 6WDWH 0DWHU 6FL > @ - 5 *ROGEHUJ - 7 *LOEHUW %LRPDWHULDOV

> @ 0 1DNDJDZD HW DO -RXUQDO RI 'HQWDO 5HVHDUFK

Use of Short Amyloidogenic Peptides for Nanotechnology Gabriela M. Guerra, SĂłnia Gonçalves, Nuno C. Santos, Ivo C. Martins Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Av. Professor Egas Moniz 1649-028, Lisbon, Portugal gguerra@medicina.ulisboa.pt Abstract Amyloid fibers, often associated with several human degenerative diseases (such as $O]KHLPHUÂśV DQG 3DUNLQVRQÂśV GLVHDVHV may also have physiological roles, having even been suggested as potential QRYHO ELRPDWHULDOV > @ ,Q JHQHUDO DP\ORLG ILEHUV VKDUH D FRPPRQ Č&#x2022;-sheet rich architecture that is behind their exceptional stability, mechanical strength and resistance to degradation, rendering them excellent nanomaterial candidates [1,2]. The potential to form amyloids (and other protein/peptide aggregates) can be predicted from the peptide sequence [1, 3].

Here, we used atomic force microscopy (AFM), circular dichroism (CD) and Fourier transform infrared spectroscopy (FTIR) to evaluate which among three possible amyloidosis models (peptides with sequence QVQIIE, ISFLIF and GNNQQNY) would form characteristic amyloid fibrils at physiologic pH conditions. FTIR and CD were used to determine the structural conformation of the amyloid fibrils formed. The CD spectra of QVQIIE are presented in Figure 1A. These spectra demonstrate that this SHSWLGH VHTXHQFH FDQ DFTXLUH D Č&#x2022;-sheet conformation characteristic of amyloid fibrils. However, at the pH and temperature conditions tested, the GNNQQNY peptide forms structures with a random coil conformation (Figure 1A), inconsistent with classical amyloid fibril morphology. Due to lower solubility, ISFLIF was prepared at a lower concentration than the other peptide sequences. As at those concentrations the structural characterization of the peptide by CD is not feasible, FTIR was used instead (Figure 1B) ,W LV FOHDU WKDW WKH ,6)/,) SHSWLGH DFTXLUHV Č&#x2022;-sheet conformation at physiologic pH, -1 -1 with a characteristic band around 1635 cm FODVVLFDO Č&#x2022;-sheet peaks are found in the 1623-1640 cm region [4]). From these results it is clear the peptide GNNQQNY, in the conditions tested, does not DFTXLUH D Č&#x2022;-sheet conformation typical of amyloid fibrils. The peptides were further investigated via their abilities to bind Congo Red (a dye commonly used to detect amyloid fibrils in solution [5]). In line with the studies of secondary structure, GNNQQNY does not bind Congo Red. Congo Red binding assays of ISFLIF and QVQIIE are presented in Figure 1C. In the presence of amyloid fibrils, Congo Red absorbance spectrum changes, resulting in a maximal spectral difference at 540 nm [5]. QVQIIE spectra did not suffer these characteristic maximal spectral differences, indicating that amyloid fibrils are not formed at the pH and temperature incubation conditions. ISFLIF, however, suffers a clear shift, indicative of amyloid structure. Having established the peptides secondary structure content, AFM was employed in the subsequent studies, as it is a microscopic technique very useful for the study of amyloid fibrils because it allows the imaging of surfaces with high resolution and sensibility (Figure 1D).

Negative and positive controls behaved as expected. GNNQQNY does not form amyloid-like structures, while QVQIIE shows structures that are not consistent with classic well-structured mature amyloid fibrils.

Regarding ISFLIF, this peptide clearly forms an amyloid fibril structure, similar to the positive control.

AFM-based morphological characterization of the ISFLIF amyloid fibrils (Figure 1E-F) shows that these fibrils have and average diameter of 159.6 Âą 3.2 nm and 10.0 Âą 0.1 nm of average height. ISFLIF amyloid fibrils formed under these physiological conditions of pH and temperature seem to be similar to standard amyloid fibrils, constituting promising biomaterials [1, 2].

AFM, CD, FTIR and Congo Red data, taken together, indicate the peptide ISFLIF as the most reproducible and amenable peptide for developing amyloid-based nanotechnology approaches, in line with previous work [2, 3], where short amyloidogenic peptides are sought for nanotechnology applications.

References [1] Cherny I and Gazit E, Angew Chem Int Ed Engl, 47 (2008) 4062 [2] Hauser C A E., Maurer-Stroh S, Martins I C, Chem Soc Rev, 43 (2014) 5326 [3] Maurer-Stroh et al., Nat Methods, 7 (2010) 237 [4] Jackson, M.; Mantsch, H. H., Crit Rev Biochem Mol Biol, 30 (1995) 95 [5] Klunk W E, Pettegrew J W and Abraham D J, J Histochem Cytochem, 37 (1989) 1273

Fig. 1. Amyloidogenic properties of three short peptide sequences, GNNQQNY, QVQIIE and ISFLIF, tested at physiological conditions of pH and temperature. (A) Far UV CD spectra of GNNQQNY and QVQIIE (dotted line: 0h of incubation; continuous line: 2 weeks of incubation). (B) FTIR spectra of ISFLIF in the amide I region (dotted line: 0h of incubation; continuous line: 2 weeks of incubation). (C) Congo Red binding assay of QVQIIE and ISFLIF. GNNQQNY shows spectra with no binding, similar to QVQIIE (data no shown) (dotted line: 0h of incubation; continuous line: 2 weeks of incubation). (D) AFM study of the three peptides morphology (center and right columns), displaying also positive and negative controls (left column). (E) Study of ISFLIF amyloid structure, imaged by AFM. (F) Height and width of ISFLIF amyloid fibrils, determined by AFM cross-sections (N = 120).

Iron Oxide Nanoparticles as Contrast Agents for Magnetic Resonance Imaging Applications 1,3

2

1

1

2

Noelia Guldris , Bárbara Argibay , Yury V. Kolen¶ko , Enrique Carbó-Argibay , Ramón Iglesias , 2 1 1 2 1,3 Francisco Campos , Laura M. Salonen , Manuel Bañobre-López , José Castillo , José Rivas 1 INL - International Iberian Nanotechnology Laboratory, Braga, Portugal Department of Neurology, Clinical Neurosciences Research Laboratory, Health Research Institute of Santiago de Compostela (IDIS), University Clinical Hospital, Santiago de Compostela, Spain 3 Department of Applied Physics, Technological Research Institute, Nanotechnology and Magnetism Lab ² NANOMAG, University of Santiago de Compostela, Spain noelia.guldris@inl.int 2

Magnetic Resonance Imaging (MRI) is a widespread technique used in the clinical field for the diagnosis of diverse diseases, such as stroke or cancer, since it allows the visualization of internal tissues and organs. In comparison with other imaging techniques, it displays some remarkable characteristics like high spatial resolution and noninvasiveness. However, a major drawback of this technique is its sensitivity: the natural contrast between healthy and damaged tissue is very low, which may complicate the diagnosis. Nowadays, contrast agents are used to increase the relaxation rates of surrounding water proton spins, which significantly enhances the clinical image resolution.

The currently used contrast agents in clinics have mostly gadolinium as the magnetic ion, but its use has several drawbacks, such as toxicity and low lifetime in the blood stream. Therefore, the development of novel contrast agents based on e.g. iron oxide is of fundamental importance to avoid toxicity and improve lifetime and multifunctionality of the system.

Here, we report on the parameters affecting the Superparamagnetic Iron Oxide Nanoparticle (SPION) relaxivity (Fig. 1). The parameters studied were the synthesis technique (hydrothermal and coprecipitation method), the polymeric coating (hydrophilic and hydrophobic polymers), and doping with 2+ 2+ magnetic and non-magnetic ions (Mn and Zn ). The in vitro validation was performed to probe the suitability of these SPIONs for biomedical applications. Hence, data of different SPIONs will be shown regarding magnetic and relaxivity properties, cytotoxicity, uptake behavior and MRI imaging capability.

Acknowledgement: this work is funded by POCTEP (Operational Programme for Cross-border Cooperation Spain-Portugal) and co-financed by the ERDF (European Regional Development Fund).

3500 3000

Zn0.4Mn0.6Fe O 2 4

2500

r2= 170 mM s

Zn0.2Mn0.8Fe O 2 4 -1 -1

r2= 122 mM s

-1 -1

1/T2

2000

Fe O 3 4 -1 -1

1500

r2= 76 mM s

1000 500 0 -5

0

5

10

15

20

25

Fe (mM)

Figure 1: Parameters studied, which affect the relaxivity values.

30

35

40

45

Use of Nano-Technology and Nanomaterial in the Development of Nanocomposite Cementitious Materials; Review for Future Research Openings Muhammad Ilyas Sheikh, Mizi Fan and Zhaohui Huang School of Engineering and Design, Brunel University, Uxbridge, Middlesex, UB8 3PH,

United Kingdom

muhammad.ilyas@brunel.ac.uk Abstract

The main binder of concrete, Portland cement, represents almost 80% of the total CO2 emissions of concrete. This environmental impact can be reduced by limiting its production and developing alternative cementitious composites. Strength of cementitious material is also an essential requirement and cannot be trade-off by these alternative means.

Development in nanotechnology has led researchers to investigate the complex structure of cement based materials at nano level to address both strength and environmental concerns.

In this review paper nanotechnology pathways, recently been paved in the field of nanocomposites for cementitious materials, are presented to understand how nano-science, nanoengineering and nano-indendation is making a great impact in the development of cementitious nanocomposite. Also generally used nanomaterial in the foregoing research to enhance strength, durability and other multifunctional properties of cementitious materials are highlighted. Among hundreds of nanomaterial available, only few of them are attracted by the researchers due to their great influence on properties the cementitious materials.

Carbon nanomaterial such as carbon nanotubes (CNTs) and carbon nanofibers (CNFs) generally used in the cementitious materials for enhancing the compressive and flexural strength while nanoparticles of metal oxides such as TiO2, SiO2, Al2O3, Fe2O3 are reported to improve the durability and multifunctional properties such as self-cleaning and selfsensing ability. Moreover, studies on nano-clays, bio-nanomaterial and waste material supplemented with nanomaterial properties are also presented to bridge the gap between previous and future research for the development of environmental friendly high strength cementitious nanocomposite with multifunctional properties.

References (Total 93 ) [01] [02] [03] [04] [05]

-D\DSDODQ $ 5 /HH % < DQG .XUWLV . ( &DQ QDQRWHFKQRORJ\ EH ÂľJUHHQÂś" &RPSDULQJ efficacy of nano and microparticles in cementitious materials", Cement and Concrete Composites, vol. 36, no. 0, pp. 16-24.

Sanchez, F. and Sobolev, K. (2010) "Nanotechnology in concrete Âą A review", Construction and Building Materials, vol. 24, no. 11, pp. 2060-2071.

Pacheco-Torgal F, Miraldo S, Ding Y, Labrincha J. Targeting HPC with the help of nanoparticles.

An overview. Constr Build Mater 2013;38:356Âą70.

Davalos Jf. Advanace materials for civil infrastructure rehabilitation and protection. New York: Seminar at The Citty College of New York;2012.

DÄ&#x201A;ĹŹÄ&#x201A;Ć&#x152;Í&#x2022; :Í&#x2DC; DÍ&#x2DC;Í&#x2022; Ä&#x201A;ĹśÄ&#x161; Ä&#x17E;Ä&#x201A;ĆľÄ&#x161;Ĺ˝Ĺ?ĹśÍ&#x2022; :Í&#x2DC; :Í&#x2DC; ͞ώϏϏϯͿÍ&#x2DC;Í&#x17E; Ä&#x201A;Ć&#x152;Ä?ŽŜ ĹśÄ&#x201A;ŜŽĆ&#x161;ĆľÄ?Ä&#x17E;Ć? Ä&#x201A;ĹśÄ&#x161; Ć&#x161;Ĺ&#x161;Ä&#x17E;Ĺ?Ć&#x152; Ä&#x201A;Ć&#x2030;Ć&#x2030;ĹŻĹ?Ä?Ä&#x201A;Ć&#x161;Ĺ?ŽŜ Ĺ?Ĺś Ć&#x161;Ĺ&#x161;Ä&#x17E; Ä?ŽŜĆ?Ć&#x161;Ć&#x152;ĆľÄ?Ć&#x161;Ĺ?ŽŜ Ĺ?ĹśÄ&#x161;ĆľĆ?Ć&#x161;Ć&#x152;Ç&#x2021;Í&#x2DC;Í&#x; WĆ&#x152;Ĺ˝Ä?Í&#x2DC;Í&#x2022; Ď­Ć?Ć&#x161; /ĹśĆ&#x161;Í&#x2DC; ^Ç&#x2021;ĹľĆ&#x2030;Í&#x2DC; KĹś EÄ&#x201A;ŜŽĆ&#x161;Ä&#x17E;Ä?Ĺ&#x161;ŜŽůŽĹ?Ç&#x2021; Ĺ?Ĺś ŽŜĆ?Ć&#x161;Ć&#x152;ĆľÄ?Ć&#x161;Ĺ?ŽŜÍ&#x2022; WÄ&#x201A;isley, Scotland, UK.

: : :

[90]

[91]

[92]

[93]

Shiho Kawashima, Pengkun Hou, David J. Corr, Surendra P. Shah, Modification of cementbased materials with nanoparticles, Cement and Concrete Composites, Volume 36, February 2013, Pages 8-15, ISSN 0958-9465, 10.1016/j.cemconcomp.2012.06.012.

Alireza Naji Givia*, Suraya Abdul Rashidb, Farah Nora A. Azizc and Mohamad Amran Influence of 15 and 80 nano-SiO2 particles addition on mechanical and physical properties of ternary blended concrete incorporating rice husk ash, Journal of Experimental Nanoscience, 2013 Vol. 8, No. 1, 1Í´18, Hamed Younesi Kordkheili, Salim Hiziroglu, Mohammad Farsi, Some of the physical and mechanical properties of cement composites manufactured from carbon nanotubes and bagasse fiber, Materials & Design, Volume 33, January 2012, Pages 395-398, ISSN 0261-3069, 10.1016/j.matdes.2011.04.027.

M. Aly, M.S.J. Hashmi, A.G. Olabi, M. Messeiry, A.I. Hussain, Effect of nano clay particles on mechanical, thermal and physical behaviours of waste-glass cement mortars, Materials Science and Engineering: A, Volume 528, Issue 27, 15 October 2011, Pages 7991-7998, ISSN 09215093, 10.1016/j.msea.2011.07.058.

Figures (Total 10)

CN Nanocomposite Engineered

Fig.1. Particle size and specific surface area related to concrete materials [03] (Adopted and modified from the article of Sanchez and Sobolev. Constr Build Mat 24, 2060Âą2071).

Fig.5. Graphical representation of data showing the enhancement of compressive strength and flexural strength using carbon fibres and carbon nanotubes; Extracted from data [42]

Large-scale graphene film synthesized by plasma treatment of Cu foil and its electromagnetic shielding property 1

1

2

2

2

3

M. Ishihara , T. Yamada , Y. Katou , M. Ameya , M. Horibe , T. Nakamura , 3 3 1 H. Nanjo , T. Ebina , M. Hasegawa 1

Nanotube Research Center, National Institute of Advanced Industrial Science and Technology (AIST), Central 5, 1-1-1 Higashi, Tsukuba, Ibaraki, Japan 2 National Metrology of Japan (NMIJ), AIST, Central 3, 1-1-1 Umezono, Tsukuba, Ibaraki, Japan 3 Research Center for Compact Chemical System, AIST, 4-2-1 Nigatake, Miyagino-ku, Sendai, Miyagi, Japan m.ishihara@aist.go.jp

Abstract Conventional transparent electrodes make use of indium tin oxide (ITO) and are commonly used in touch screens, Ă&#x20AC;at panel displays and solar cells. Nearly 90% of ITO film market is for the touch screen application, which is expected to grow more and more in the future. Graphene is potential candidates for transparent conductive films for electrical and optoelectronic devices and various other applications due to its high electrical conductivity, chemical and physical stability. Graphene has been prepared by several methods, including precipitation on a silicon carbide surface, mechanical exfoliation from graphite, reduction of exfoliated graphene oxide, and growth by thermal chemical vapor deposition (CVD) on catalytic metal surfaces [1]. Bae et al, reported the synthesis of graphene by thermal CVD on a copper substrate at high deposition temperature of 1000 degree C and fabrication of transparent graphene electrodes [2]. We have synthesized high-quality graphene films by microwave plasma treatment of a copper substrate with Joule heating using low concentration carbon source [3]. The copper foil with A4 (211 mm X 297 mm) size was used as substrate. Few-layer graphene was deposited on the copper foil for a few minutes. The transfer of the graphene films to a desired target substrate is enabled by the wet-etching of the underlying copper foil. This is carried out by treating the film with an aqueous (NH4)2S2O8 solution after a support material is covered on the graphene/copper surface, in our case a surface protective sheet. The surface protective sheet is attached to the graphene/copper surface by using a film laminating roller with applying pressure. The result in a free-standing graphene/sheet film that can be handled easily and rinsed with deionized water to remove residual etchant. The graphene/sheet film is placed on the 188-Pm thick polyethylene terephthalate (PET) substrate (graphene facing the surface). Finally, the surface protective sheet is removed from a sheet/graphene/PET film. We measured the transmittance and sheet resistance of the graphene/PET by using a haze meter and four probe method, respectively. The transmittance was 96% (except PET substrate) and the sheet resistance was about 500 ohm. The electromagnetic interference (EMI) shielding effectiveness (SE) of the graphene film was measured by using two waveguide-to-coaxial adapters and a vector network analyzer. The SE of the graphene film was more than several decibel.

References [1] Xuesong Li, Weiwei Cai, Jinho An, Seyoung Kim, Junghyo Nah, Dongxing Yang, Richard Piner, Aruna Velamakanni, Inhwa Jung, Emanuel Tutuc, Sanjay K. Banerjee, Luigi Colombo, Rodney S. Ruoff, Science, 324 (2009) 1312.

[2] Sukang Bae, Hyeongkeun Kim, Youngbin Lee, Xiangfan Xu, Jae-Sung Park, Yi Zheng, Jayakumar Balakrishnan, Tian Lei, Hye Ri Kim, Young Il Song, Young-Jin Kim, Kwang S. Kim, Barbaros O¨zyilmaz, Jong-Hyun Ahn, Byung Hee Hong, Sumio Iijima, Nature Nanotechnol., 5 (2011) 574.

[3] Ryuichi Kato, Kazuo Tsugawa, Yuki Okigawa, Masatou Ishihara, Takatoshi Yamada, Masataka Hasegawa, Carbon, 77(2014)823.

Mechanical and electrochemical properties of niobium oxide layers deposited on Ti alloys by reactive magnetron sputtering process 1

1

2

2

2

M. Kalisz , M. Grobelny , M. Mazur , D. Wojcieszak & D. Kaczmarek 1 Motor Transport Institute, Warsaw, Poland 2 Faculty of Microsystems Electronics and Photonics Wroclaw University of Technology, Wroclaw, Poland malgorzata.kalisz@its.waw.pl Abstract Titanium and titanium alloys are widely used in a variety of engineering applications, where combination of mechanical and chemical properties is of crucial importance. Aerospace, chemical and automotive industries as well as medical device manufacturers also benefited from the outstanding properties of titanium alloys. Although, titanium alloys exhibit high strength and toughness, they are susceptible to chemical and electrochemical degradation. They may corrode and / or wear, leading to the degradation of material properties. In order to improve the mechanical and electrochemical properties of titanium alloys surface, surface modification is often required.

Nb2O5 for several years is investigated as possible candidate for corrosion barrier coatings [1].

Properties of niobium oxide depend on deposition process and its parameters, such as reactant gas flow or pressure. It has been shown by Ramirez et al. [2] that hardness of thin niobium oxide films increased from 3.9 GPa to 5.3 GPa with increasing pressure and oxide content. On the other hand Chappe et al. [3] determined values hardness of niobium oxide films of about 6 GPa and Cetinorgu et al. [4] measured the hardness of amorphous Nb2O5 films deposited by dual ion beam sputtering as a function of the ion energy and the values ranged between 5.5 and 6.5 GPa The main objective of this research is to obtain new and innovative materials for titanium alloy (Ti6Al4V) corrosion protection, based on niobium oxide thin films deposited by reactive magnetron sputtering process.

The structure, electrochemical corrosion and mechanical behavior of the alloy before and after niobium oxide thin films deposition were studied by SEM, potentiostat and nanohardness tester. The results show that the deposition of niobium oxide layers on the surface of the Ti 6Al4V alloy, significantly improved corrosion resistance of titanium alloy in e.g. simulated body fluids and titanium alloy surface mechanical properties.

7KHVH UHVHDUFK ZDV VSRQVRUHG E\ ,Q*UDI7L SURMHFW ³Innovative engine valves with improved performance, made of graphene-WLWDQLXP DOOR\´ References [1] T. Ushikubo, Catalysis Today 57 (2000) 331-338, [2] G Ramirez, S.E. Rodil, S. Muhl, D. Turcio-Ortega, J.J. Olaya, M. Rivera, E. Camps, L. EscobarAlarcón, Journal of Non-Crystalline Solids 356 (2010) 2714±2721, [3] J.M. Chappe, P. Carvalho, S. Lanceros-Mendez, M.I. Vasilevskiy, F. Vaz, A.V. Machado, M. Fenker, H. Kappl, N.M.G. Parreira, A. Cavaleiro, E. Alves, Surface & Coatings Technology 202 (2008) 2363, [4] E. Cetinorgu, B. Baloukas, O. Zabeida, J.E. Klemberg-Sapieha, L. Martinu, Applied Optics 48 (2009) 4536

Glycine and lysine assays with enzymatic reactions and examination of detection conditions Akimitsu KUGIMIYA, Rie FUKADA, Shoko AMANO Center for Industry and Public Relations, Hiroshima City University, 3-8-24 Senda-machi, Naka-ku, Hiroshima 730-0052, JAPAN kugimiya@hiroshima-cu.ac.jp Abstract Glycine is the amino acid which constitutes collagen and it has a role which maintains elasticity with glowing skin. It also exists in the backbone or the brain stem mostly, and works as neurotransmitter of a control system of the central nerves. In contrast, lysine tends to occur at the lowest levels in the human body; further decreases in lysine concentration cause failures in liver function that lead to increased serum saturated fat and cholesterol levels [1]. Analyses of free amino acids in biological fluids may therefore be useful in determining disease status in clinical diagnoses [2-3].

For the analysis of each amino acid concentration, such as high-performance liquid chromatography (HPLC) has been used generally; however, the conventional analytical methods are burdensome in terms of cost, time, and space requirements. HPLC methods for amino acids, for example, take several hours to complete. The development of simple and rapid analytical tools for measuring amino acid concentrations is desirable for the clinical diagnostics and food industries.

We have studied a novel approach for the detection of each amino acid that involved the use of aminoacyl-tRNA synthetase (aaRS) as a molecular recognition element [4-7], because aaRS mediates biosynthesis of proteins and peptides in the body, thus it is expected to a selective binding ability for corresponding amino acid.

In this study, in order to obtain a simple amino acid detection system, for the specific detection of glycine and lysine, glycyl-tRNA synthetase and lysyl-tRNA synthetase were used as the each amino acid recognition element respectively, and these were coupled to the measurement of hydrogen peroxide via several enzymatic reactions, and the results were DQDO\]HG E\ WKH 7ULQGHU¶V UHDJHQW spectrophotometric method and absorbance was measured at 556 nm.

The consecutive enzymatic reactions used in this study are as follows: SerRS binds to its cognate amino acid, serine, and releases inorganic pyrophosphate (Scheme, Equation [1]). Hydrogen peroxide (H2O2 ZDV SURGXFHG E\ WKH UHDFWLRQV VKRZQ LQ (TXDWLRQV > @ DQG > @ DQG 7ULQGHU¶V UHDJHQW (TOOS) was injected into the reaction mixture (Equation [4]). The absorbance change at 556 nm was measured using a microplate reader, and the selective and quantitative responses of the biosensor were evaluated. This approach provided selective quantitation of up to 25 M glycine and also showed selective response to glycine in 100 mM Tris-HCl buffer (pH 8.0) selectively (Figure 1).

This work was partly supported by JSPS KAKENHI Grant Number 25330344.

References [1] [2] [3] [4] [5] [6] [7]

A. Sánchez, D.A. Rubano, G.W. Shavlik, R. Hubbard, M.C. Horning, Arch Latinoam Nutr., 38, (1988) 229-238.

Y. Noguchi, Q.W. Zhang, T. Sugimoto, Y. Furuhata, R. Sakai, M. Mori, M. Takahashi, T. Kimura, T., Am. J. Clin. Nutr., 83, (2006) 513S-519S. Y. Miyagi, et al., PLoS ONE, 6, (2011) 1-12.

A. Kugimiya, M. Morii, T. Ohtsuki, Anal. Biochem., 378, (2008) 90-92.

A. Kugimiya, E. Takamitsu, Mater. Sci. Eng. C, 33, (2013) 4867-4870.

A. Kugimiya, R. Fukada, D. Funamoto, Anal. Biochem., 443, (2013) 22-26.

A. Kugimiya, E. Matsuzaki, Appl. Biochem. Biotech., (2014) accepted.

Figures

Scheme 1 Enzymatic reaction equations

Figure 1 Selectivity test for 20 natural amino acids during Glycine sensing. Twenty natural amino acids, each at a concentration of 50 M, were added to the reaction mixture, and the absorbance at 556 nm was measured using a microplate reader. Data represent the average of 3 measurements, and the standard deviation is indicated by error bars.

Transmission of signals using white and visible LEDs for VLC applications 1,2

1,2

1

1,2

1,2,3

P. Louro , V. Silva , I. Rodrigues , M. A. Vieira , M. Vieira Electronics Telecommunication and Computer Dept. ISEL, R. Conselheiro Emídio Navarro, 1959-007 Lisboa, Portugal 2 CTS-UNINOVA, Quinta da Torre, Monte da Caparica, 2829-516, Caparica, Portugal.

3 DEE-FCT-UNL, Quinta da Torre, Monte da Caparica, 2829-516, Caparica, Portugal

1

plouro@deetc.isel.ipl.pt Abstract Recent developments in LEDs allowed them to be used in environmental lighting and have revealed many advantages over incandescent light sources including lower energy consumption, longer lifetime, improved physical robustness, smaller size, and faster switching. Besides this general lighting application, LEDs are now used in other specific fields such as automotive headlamps, traffic signals, advertising, and camera flashes. However another emerging field of application is in advanced communications technology due to its high switching rates. Thus, the visible light spectrum is currently being used in the Visible Light Communication (VLC) technology, taking advantage of the lighting infrastructure based on white LEDs. These energy-saving white light sources devices were enabled by the invention of efficient blue LEDs. In this paper we propose the use of a multilayered pinpin device based on a-SiC:H to work as a photodetector operating in the pertinent range of operation for VLC (375 nm ± 780 nm) using as optical sources white and visible wavelength LEDs [1]. The device consists of a p-i'(a-SiC:H)-n/p-i(a-Si:H)-n heterostructure with low conductivity doped layers, sandwiched between two transparent contacts (Figure 1). It works as an optical filter in the visible range with tunable spectral sensitivity dependent on both applied bias and type of steady state optical bias (wavelength, intensity and direction of incidence on the device).

Optoelectronic characterization of the device is presented and includes with spectral characterization of the optical sources (figure 2), spectral response, transmittance and I-V characteristics, with and without background illumination of the photoddetector (Figure 3). Results show that when the device is biased with front optical steady state light of short visible wavelength (400 nm) superimposed with the pulsed light emitted from the optical transmission sources, it exhibits an increased output current in the long part of the spectrum (550-650 nm), and a reduction of the same photocurrent for the short wavelengths (400-500 nm). An opposite behavior is observed when the wavelength of the background is changed to longer values. A comparison of the performance of white LEDs and visible wavelengths is presented.

Results show that, front background enhances the light-to-dark sensitivity of the medium, long and infrared wavelength channels and quench strongly the low wavelength, depending optical amplification on the background intensity. The change of the impinging side of the steady state illumination produces the reverse effect, as the output photocurrent is enhanced under short wavelength signals and range and strongly reduced it under the long wavelength (figure 4).

A decoding algorithm for the detection of different optical signals is presented and discussed with a selfrecovery error procedure. A capacitive optoelectronic model supports the experimental results (figure 5) and explains the device operation. A numerical simulation will be presented.

References [1] ³+RPH 9/& XVLQJ SLQSLQ D-6L& + PXOWLOD\HU GHYLFHV´, P. Louro, V. Silva, I. Rodrigues M. A. Vieira, M. Vieira, Mater. Res. Soc. Symp. Proc. Vol. 1693 © 2014 Materials Research Society, DOI: http://dx.doi.org/10.1557/opl.2014.569 [2] ³9LDELOLW\ RI WKH XVH RI DQ D-6L& + PXOWLOD\HU GHYLFH LQ D GRPHVWLF 9/& DSSOLFDWLRQ´, P. Louro, V. Silva, M. A. Vieira, M. Vieira, physica status solidi (c), Special Issue: E-MRS 2014 Spring Meeting ± Volume 11, Issue 11-12, pages 1703±1706, November 2014, Symposium X, DOI: 10.1002/pssc.201400035

0,8

0,7

0,7

Optical intensity (a. u.)

Optical intensity (a. u.)

0,8

0,6 0,5 0,4 0,3 0,2 0,1 0,0 400

500

600

700

0,6 0,5 0,4 0,3 0,2 0,1 0,0 400

800

Wavelength (nm)

500

700

800

b)

a)

Emission spectrum of the warm white LEDs: a) phosphor based; b) tri-chromatic based.

Photocurrent (A)

Fig.2

1,5x10

-7

1,0x10

-7

5,0x10

-8

No optical bias Front side bias Back side bias

450

500

550

600

650

700

Wavelength (nm)

Fig. 3 Spectral photocurrent under dark conditions and using front and back violet light.

7

7 Dark Front bias Back bias

Red optical signal

5 4 3 2 1 0

1

Dark Front bias Back bias

5 4 3 2 1 0

2

Time (ms)

Blue optical signal

6

Photocurrent (PA)

6

0

635 nm

450 nm

0,0 400

Fig.1 Simplified schematic diagram of the device structure.

Photocurrent (PA)

600

Wavelength (nm)

0

1

2

Time (ms)

a)

b)

Fig. 4 Transient photocurrent measured under pulsed illumination of the internal LEDs of the trichromatic based white LED: a) red and b) blue internal LED, without optical bias and under front and back optical bias.

7

DBIB

Exper. Simul.

-

+

C1

R1 Q1

+ -

DRIR

Q2 R2

Photocurrent (PA)

6

C2

4 3 2 1 0

a)

Front bias: Back bias:

5

0

1

Time (ms)

2

b)

Fig. 5 a) ac equivalent circuit of the optoelectronic device, b) Simulation and experimental data of the combined signal with front and back optical bias (C1=0.8 nF, R1 NÂ&#x; &2 (front)=0.2 nF, C2 (back)=0.15 nF R2 NÂ&#x;

Surface morphology and corrosion investigation of AZ91RC magnesium alloy B. Mingoa, R. Arrabala, M. Mohedanob, A. Pardoa, E. Matykinaa, M.C Merinoa a

b

Departamento de Ciencia de Materiales, Facultad de Ciencias QuĂ­micas, Universidad Complutense, 28040, Madrid, Spain

HelmholtzZentrumGeesthacht, Magnesium Innovation Centre, Institute of Materials Research, Max-Planck-Str. 1, D-21502 Geesthacht, Germany.

E-mail: beatrizmingo@ucm.es

ABSTRACT Rheocast processing of AZ91 magnesium alloy was evaluated in terms of microstructure and corrosion resistance. Rheocasting leads to a globular microstructure of D-Mg spheres separated by an interconnected E-Mg17Al12 (E-phase) network. Findings revealed that early stages of corrosion were located at the center of D-Mg globules and more importantly at D-Mg/E-phase interfaces due to galvanic coupling as predicted from surface potential maps. Electrochemical, hydrogen evolution and weight loss measurements demonstrated the superior corrosion resistance of the rheocast alloy. This was attributed to an improved barrier effect of the EMg17Al12 phase related to its morphology, quantity and composition. For long immersion times, only small attacked areas were observed which corresponded to randomly corroded D-Mg globules. High resolution 3D measurements of the corroded areas after removal of the corrosion products were obtained in order to further evaluate the corrosion morphology.

Magnetic and morphologic properties of Alnico-based rare-earth free permanent magnets Farzin Mohseni, M. J. Pereira, N. M. Fortunato, J. S. Amaral, A. C. Lourenço, J. M. Vieira Department of Physics, University of Aveiro, 3810-193, Aveiro, Portugal f.mohseni@ua.pt Abstract Due to recent dramatic increases in the price of rare-earth elements, rare-earth free permanent magnet research is nowadays a very active field [1]. $OQLFR 9 DOOR\V ILUVW GLVFRYHUHG LQ WKH œV are hard ferromagnets, with high working temperatures, albeit with modest coercivity, below 1 kOe [2]. This makes their energy product (~12 MGOe) compare unfavorably with rare-earth based NdFeB magnets (~55 MGOe). Recently, an unusually high coercivity value, up to ~ 10 kOe, was reported for DCsputtered Alnico V thin-films on Silicon substrates [3, 4], due to the formation of a novel Body Centered Tetragonal Fe-Co-Si phase, a result of diffusion of Si ions from substrate to thin film. This diffusion mechanism is still unclear, and the chemical composition and saturation magnetization of this novel phase are not yet characterized.

We report on the effects of deposition temperature and post heat treatments on the morphology and magnetic properties of Alnico V thin films prepared by RF-sputtering. The sputtering target was of commercial Alnico V alloy, and substrates were of 700 Âľm thick Si(100). Samples of 180 nm thickness were prepared at different deposition temperatures, ranging from room temperature to 560 Č&#x161;C. Postdeposition heat treatments in vacuum at 600, 800 and 900 Č&#x161;C, followed by quenching in liquid Nitrogen and slow-cooling, were performed.

Atomic Force Microscopy (AFM) shows that both an increase of deposition temperature as well as post heat treatments lead to a considerable increase of roughness, from < 0.8 nm to 80 nm, for heat treatments at 600 Č&#x161;C, and 50 nm for a deposition temperature of 500 Č&#x161;C (Figure 1).

The chemical composition of the thin films was analyzed by Electron Dispersion Spectroscopy (EDS) in a Scanning Electron Microscope (SEM). The composition of films deposited at room temperature, matches that of the target, while for higher substrate temperatures the ratio between transition metals is altered, and post-deposition heat treatments introduce contaminations to the thin films. Figure 2 shows the cross-section SEM image of the as-made and heat treated films.

Magnetization analysis using a Vibrating Sample Magnetometer (VSM) shows that substrate temperature affects the saturation magnetization, lowering it drastically for high temperatures. In the case of heat treatments this decrease is smoother, but still quite substantial, particularly for quenched samples. Coercivity is unaffected by deposition temperatures in this range, while increasing considerably (from < 20 Oe for as-deposited films up to 480 Oe) in heat-treated samples (Figure 3).

Future studies will focus on film thickness and substrate temperature optimization, and the control of surface roughness under heat-treatments, by adding a capping layer to the films (Ag, Ta), preventing also the observed oxidation of the surface during heat treatment and quenching.

We acknowledge funding from FEDER/COMPETE through FCT, FCOMP-01-0124-FEDER-037271 (PEst-C/CTM/LA0011/2013) and EXPL/CTM-NAN/1614/2013 - FCOMP-01-0124-FEDER-041688.

References [1] Narayan Poudyal and J Ping Liu, ³$GYDQFHV LQ 1DQRVWUXFWXUHG 3HUPDQHQW 0DJQHWV 5HVHDUFK´ Journal of Physics D: Applied Physics 46 (2013) 043001 (23pp).

[2] K. H. J. Buschow, ³1HZ 'HYHORSPHQWV LQ +DUG 0DJQHWLF 0DWHULDOV´ Reports on Progress in Physics 54 (1991) 1123-1213.

[3] O. Akdogan, G. C. Hadjipanayis, ³$OQLFR 7KLQ )LOPV ZLWK +LJK &RHUFLYLWLHV XS WR N2H´ Journal of Physics: Conference Series 200 (2010) 072001.

[4] O. Akdogan, W. Li, G. Hadjipanayis, ³+LJK &RHUFLYLW\ SI $OQLFR 7KLQ )LOPV (IIHFW RI 6L 6XEVWUDWH DQG WKH (PHUJHQFH RI 1RYHO 0DJQHWLF 3KDVH´ Journal of Nanoparticle Research (2012) 14 891.

Figures

Figure 1 AFM image of a) as-deposited E DIWHU KHDW WUHDWPHQW DQG F GHSRVLWHG DW ŕĄ&#x2C6;C.

Figure 2 Cross sectional SEM image of a) as-deposited, b) after heat treatment

Figure 3 Effects of a) heat treatment followed by slow cooling, b) heat treatment followed by quenching and c) deposition temperature on hysteresis loop

Effect of biodegradation on PLA/graphene-nanoplatelets composites mechanical properties and biocompatibility Artur M. Pinto1,2, Carolina Gonçalves1, Inês C. Gonçalves2, Fernão D. Magalhães1 1

LEPABE, Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal 2

INEB, Universidade do Porto, Rua do Campo Alegre, 823, 4150-180 Porto, Portugal arturp@fe.up.pt

Abstract Two types of graphene-nanoplatelets (GNP-M and GNP-C) were incorporated in PLA (poly(lactic acid)) by melt blending. Materials were biodegraded during 6 months and characterized by XRD, tensile tests, DMA and biocompatibility assays. For both fillers, low loadings (0.25 wt.%) improved mechanical properties and decreased their decay until 6 months biodegradation. PLA degradation decreased its toughness (AUC) by 10 fold, while for PLA/GNP-M and C after 6 months degradation, toughness was only reduced by 3.3 and 1.7 fold, respectively. Comparing with PLA, PLA/GNP-M and C composites presented similar (HFF-1) fibroblasts adhesion and proliferation at the surface and did not released toxic products (6 months).

Introduction Graphene is a single layer of sp2 carbon atoms arranged in a honeycomb structure and possesses extraordinary mechanical strength and an extremely high surface area. [1] A commercial available product, with reduced cost comparing with single layer graphene, graphene nanoplatelets (GNPs), are constituted by few stacked graphene layers, possessing oxygen containing functional groups in the edges. GNPs present high aspect ratio, thus forming a percolated network in composites, with large interfacial interaction between platelets and polymer matrix, mainly in the edges, resulting in effective load transfer and increased strength. [2] Moreover, these materials were shown to be non-toxic when incorporated in low percentages into PLA. [3] The potential of GNPs as polymers fillers, has been observed in our previous study, in which improvements in mechanical properties of PLA thin films were obtained at filler loadings bellow 1 wt.%. Solvent mixing was used for GNPs incorporation, [4] however the use of solvents should be avoided due to the toxicity of residues that may remain in the materials, and for industrial workers [5]. Lahiri et al. improved ultrahigh molecular weight polyethylene mechanical properties producing composites by electrostatic deposition of GNPs 1 wt.%. However, composites were toxic to osteoblasts because filler leaching occurred. [2] Thus, melt blending, which assures complete embedding of GNPs in polymer matrix preventing filler leaching, is studied in this work as a green method for production of PLA/GNPs composites.

Materials and Methods PLA 2003D, was purchased from Natureworks. Graphene-nanoplatelets, grade C750 (GNP-C) and M-5 (GNP-M) were acquired from XG Sciences. PLA/GNP-M and C 0.25 wt.% composites were prepared by melt blending in a Thermo Haake Polylab (180 °C, 15 min, 25 rpm), and moulded in a hot press (190 ºC, 2 minutes) into thin sheets (0.3-0.5 mm). Samples were immersed in 50 mL PBS in sterile conditions and incubated for 6 months (37 °C, 100 rpm). X-Ray diffraction (XRD) analysis, was performed using a Philips X´Pert diffractometer. Tensile properties of the composites (60x15 mm) were measured (Mecmesin Multitest-1d, Mecmesin BF 1000N) at room temperature and strain rate of 10 mm min-1.

Dynamical mechanical analysis (DMA) was performed using a DMA 242 E Artemis (Netzsch) in tension assays (6N, 10 minutes) with 10 minutes recovery. Biocompatibility of materials was evaluated using HFF-1 cells cultured at the surface of PLA, PLA/GNP-M and C 0.25 wt.% films (Ø = 5.5 mm) and in direct contact with materials extracts obtained after 6 months incubation in PBS (50 µL in 150 µL DMEM+, after 24h cell grow). In both assays cells were seeded in 96 well plates (7500 cells per well) and 20 µL resazurin solution added at 24, 48, and 72h and incubated for 3h, fluorescence Ȝex/em=530/590 nm) read and metabolic activity evaluated (Metabolic activity (%) = Fsample/FPLA x 100).

Suitable controls were performed for both biocompatibility assays.

Results and discussion XRD GNP-M and C powders present similar XRD spectra, typical of carbon materials, with an intense peak around 31°, and two broad peaks around 50° and 65°. PLA, before (0M) and after 6 months (6M) biodegradation, presents similar spectra with two broad peaks, the first, around 20°, is more intense than the second, around 35°. PLA/GNP-M 0.25 wt.% 0 and 6M present similar spectra, with PLA and GNP-M peaks being observed, which confirms the filler presence in polymer matrix. For PLA/GNP-C 0.25 wt.% 0M and 6M spectra are also similar, however GNP-C peak is less intense than GNP-M peak.

Tensile tests

Incorporation of GNP-C and M in PLA increased its Young´s modulus by 14 %. Also, tensile strength is increased by 20% with GNP-C incorporation and by 6% with GNP-M. Improvements in toughness of 20% are only observed for GNP-C. After 6 months biodegradation no significant changes are observed in Young´s modulus for all materials tested. Decreases in tensile strength, elongation at break, and toughness are respectively, for PLA of 2.6, 2.5, and 10 fold, for GNP/PLA-M of 1.6, 1.8 and 3.3 fold, and for GNP-C of 1.4, 1.4 and 1.7 fold. Thus, the presence of the fillers prevents decreases of PLA mechanical properties with biodegradation, namely tensile strength, elongation at break and toughness.

Also, GNP-C incorporation seems to have a more beneficial effect than GNP-M, especially in toughness.

DMA Figure 1 shows that for PLA, dLf (final, at 6N) after 10 cycles before degradation was of 14.2 µm, being of 13.7 and 13.2 µm for PLA/GNP-M and C 0.25 wt.%, respectively. After 6 months degradation, PLA sample ruptured after 4 cycles (1.A) reaching a dLf of 56.3 µm, PLA/GNP-M and C 0.25 wt.% did not ruptured (1.B,C) and presented a slight increase in dLf, which were of 16.8 and 16.7 µm, respectively.

These results are in agreement with those obtained in tensile tests, with a significant decay in PLA mechanical properties after 6 months biodegradation and small effects observed for PLA/GNP-M and C 0.25 wt.%. Thus, fillers are reinforcing the polymer matrix and retarding decrease of its mechanical properties. Materials degradation was confirmed by GPC-SEC and SEM (results not shown).

Cell adhesion and proliferation assays HFF-1 cell metabolic activity at PLA surface was 75% at 24 and 48h, and 94% at 72h, comparing with cells at tissue culture treated surface of 96 well plates. PLA/GNP-M and C 0.25 wt.%, metabolic activity never decreased below 90%, for both composites in comparison with PLA. Thus, fillers incorporation has no impact in cell adhesion and proliferation at materials surface.

Degradation products cytotoxicity A control performed with PBS (37 ºC, 100 rpm, 6 months) presented similar cell metabolic activity (24, 48, 72h) to PLA 6M degradation products, which shows that they are not toxic. Figure 2 shows that degradation products of PLA/GNP-M and C 0.25 wt.% 6M are not toxic (24, 48, 72h), comparing with PLA 6M, according to ISO 10993-5:2009(E), which considers toxic a material that decreases cell viability below 70% of negative control for cell viability. Also, cell morphology is normal and similar for all conditions tested (images not shown).

Conclusions GNP-M and GNP-C incorporation in PLA matrix at low loadings (0.25 wt.%) improved mechanical properties and decreased their decay until 6 months biodegradation. These nano-fillers can be used to tune PLA mechanical performance during biodegradation. PLA/GNP-M and C composites allow similar HFF-1 cell adhesion and proliferation at the surface and do not release toxic products.

References [1] Kim K, Abdala A and Macosko W, Macromolecules, 43 (2010) 6515. [2] Lahiri D, Rupak D, Cheng Z, SocarrazNovoa I, Bhat A, Ramaswamy S, Agarwal A, ACS Appl. Mater. Interfaces, 4 (2012) 2234. [3] Pinto AM, Moreira S, Gonçalves IC, Gama FM, Mendes AM, Magalhães FD., 2013. Biocompatibility of poly(lactic acid) with incorporated graphene-based materials, Colloids Surf B Biointerfaces, 104 (2013) 229. [4] Pinto AM, Cabral J, Tanaka DA, Mendes AM, Magalhães FD, Effect of incorporation of graphene oxide and graphene nanoplatelets on mechanical and gas permeability properties of poly(lactic acid) films, Polymer International, 62 (2013) 33. [5] Pinto AM, Gonçalves IC, Magalhães FD, Colloids and Surf B Biointerfaces, 111 (2013) 188.

The influence of surface preparation on the corrosion and mechanical properties of Ti6Al4V titanium alloy 1 1 1 Marcin Ornowski , Marcin Grobelny , 0DáJRU]DWD .DOLV] 1

Motor Transport Institute, Jagiellonska 80, 03-301 Warsaw, Poland marcin.ornowski@its.waw.pl

The physical, chemical and mechanical properties of titanium alloys make this materials an appropriate candidate for a variety of technical applications. The highest strength to weight ratio of all metals up to 600°C and an excellent resistance against wet corrosion due to spontaneous formation of a passivating oxide layer have introduced titanium components into the fields of chemical, aerospace and biomedicine engineering. The oxides layers are barrier between the surrounding environment and the underlying metallic titanium. Nevertheless, in all materials the passive layer can be mechanically -

damaged and also in the presence of aggressive anion species, especially fluoride ions F , oxides layer is not sustainable. This leads to a significant reduction in corrosion resistance of titanium alloy.

Various surface modification technologies have been proposed and investigated with a view to improving the corrosion and mechanical properties of titanium alloys, including anodizing, laser alloying, coating techniques, heat treating processes and ion implantation processes. However, the continued search for new methods of surface modification of titanium alloys to improve their mechanical parameters and corrosion resistance is under way. These methods include also plasma technologies i.e.: the plasma enhanced chemical vapour deposition process (PECVD) and magnetron sputtering process preparation of thin dielectric layers are growing in popularity. However, before any process of coatings manufacturing, it is appropriate to surface preparation of metal alloy.

The paper focuses on the comparative studies of corrosion and mechanical properties of Ti6Al4V titanium alloy after surface preparation by different methods: mechanical polishing and electrochemical polishing, and influence on the corrosion properties of nanocoatings.

The tests were done by means of voltametric measurements in a fluoride solution. Surfaces of the titanium alloy was characterized using atomic force microscope, nanoindentation measurements and scanning electron microscope.

7KH UHVXOWV SUHVHQWHG LQ WKLV SDSHU KDYH EHHQ REWDLQHG ZLWKLQ WKH SURMHFW ´,Q*UDI7L´ GRAFTECH/NCBR/14/26/2013) in the framework of the National Centre for Research and Development, Graf-Tech Programme.

Adsorption equilibrium, kinetics and thermodynamics of CdTe quantum dots with distinct cappings using different solid supports S. Sofia M. Rodrigues, Christian Frigerio, João L. M. Santos, M. Lúcia M. F. S. Saraiva, Marieta L. C. Passos REQUIMTE, Departamento de Ciências Químicas, Faculdade de Farmácia, Universidade do Porto, Rua de Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal marietapassos@gmail.com Abstract Semiconductor nanocrystals, or quantum dots (QDs) have been used, during the last decade, as bioimaging tools with great potential to definite chemosensors with different applications [1]. In order to improve the applicability of these nanomaterials in chemosensors, the immobilization of quantum dots onto solid supports has been used [2]. The immobilization enables multiple or repetitive uses and when compared with the consecutive utilization of successive batches, it allows a more sustainable and rational utilization. In addition, the immobilization assures a more cost-effective operation, minimization of reagent consumption and waste production. It also allows stable measurements and consequently reproducible analytical signals.

In this work we have evaluated distinct strategies to carry out the immobilization of QDs onto solid supports (Figure 1). It was studied solid supports with distinct characteristics and it was evaluated the influence of QDs capping and size, concentration, pH, temperature, contact time between the solid and the QDs (Figure 2), etc.

Adsorption equilibrium was established and the maximum adsorption of QD on the solid support was evaluated. In order to analyze the equilibrium data, Freundlich and Langmuir isotherms were used and kinetic data were fitted to the pseudo-first-order and pseudo-second-order models. It was also calculated different thermodynamic parameters as Gibbs free energy, enthalpy and entropy and the stability of immobilized QDs was confirmed.

References [1] C. Frigerio, D.S.M. Ribeiro, S.S.M. Rodrigues, V.L.R.G. Abreu, J.A.C. Barbosa, J.A.V. Prior, K.L. Marques, J.L.M. Santos, Analytica Chimica Acta, 735 (2012) 9.

[2] C. Frigerio, J. L. M. Santos, J. A. C. Barbosa, P. Eaton, M. L. M. F. S. Saraiva, M. L. C. Passos, Chem. Commun., 49 (2013) 2518.

Acknowledgments This work received financial support from the European Union (FEDER funds through COMPETE) and National Funds (FCT, Fundação para a Ciência e Tecnologia) through project PestC/EQB/LA0006/2013. The work also received financial support from the European Union (FEDER funds) under the framework of QREN through Project NORTE-07-0124-FEDER-000067. Marieta L. C. Passos thanks FCT, Pos-doc grant (SFRH/BPD/72378/2010). S. Sofia M. Rodrigues thanks FCT and FSE for the Ph.D. Grant (SFRH/BD/70444/2010).

Figures

Figure 1: Fluorescence microscopy images of adsorbed GSH QDs (A) and MPA QDs (B) on CPG and CB solid supports, respectively.

8.0 7.0

qt (mg g-1)

6.0 5.0 4.0 3.0 2.0

1.0 0.0

0

100

200

300

400

500

Time (min) Figure 2: Effect of time on the adsorption efficiency of QDs by solid support. GSH-4' Ć&#x201D; 03$-4' Ÿ

TGA-4'V Ĺś DQG &<6-4'V Ć&#x2021;

Gd3+ Functionalized Iron-Filled Multi-Walled Carbon Nanotubes for MRI Imaging and Magnetic Hyperthermia Cancer Therapy Taze Peci University of London, UK A simple wet chemical method involving only sonication in aqueous GdCl 3 solution was used for surface functionalization of iron-filled multi-walled carbon nanotubes with gadolinium. The soni-cation process led to the formation of functional groups on the sidewalls which provide active nucleation 3+ sites for the loading of Gd ions, the desirable oxidation state for MRI contrast agent functionality.

3+ Characterization by EPR, EELS, and HRTEM confirmed the presence of Gd ions on the sidewall surface and defect sites. The room temperature ferromagnetic properties of the encapsulated iron nanowire, saturation magnetization of 40 emu/g and coercivity 600 Oe, were maintained after surface functionalization. Heating functionality in an r.f. applied magnetic field was quantified through the measurement of specific absorption rate: 50 W/gFe at magnetic field strength 8 kA/m and frequency of 696 kHz. These results demonstrate the viability as dual-functioning MRI imaging and magnetic hyperthermia structures for cancer therapy.

Scanning Thermal Microscopy: unraveling and mapping thermal phenomena at the nanoscale 1

1

1

M. J. Pereira , J. S. Amaral , N. J. O. Silva , V. S. Amaral 1

1

Departamento de FĂ­sica and CICECO, Campus de Santiago, Universidade de Aveiro, 3810-193 Aveiro, Portugal mariasapereira@ua.pt

Abstract There has been growing interest in obtaining greater knowledge on heat transport phenomena in nanostructured materials, since they are often determinant for the performance of modern micro and nano-devices, such as sensors possessing nano-sized features and thermoelectric nanomaterials.

Furthermore, nanoscale thermal properties assume great relevance in modern electronic circuits that dissipate power at the nanoscale.[1] Scanning thermal microscopy (SThM) is a powerful tool with a leading role concerning probing and mapping of local thermal properties of materials and heat generation with nanometric spatial resolution. Based on an atomic force microscope (AFM), the SThM uses a specialized heated thermal probe designed to act as a thermometer instead of the conventional AFM tip. Since its invention, AFM revealed itself a fundamental mean for imaging and introducing features at the nanoscale that alter the structure and properties of the materials. Enabling self-heating on a conventional AFM tip paved the way for its implementation, in the form of Scanning Thermal Microscopy, not only in a wide variety of manufacturing and imaging applications with unmatched quality, but also as a leading technique in the search for thermal functional properties. Determining and acting on the thermo-physical properties of microstructures is thus of great use in understanding/modelling heat transfer and macroscopic properties of heterogeneous materials. As an example, the study of contrast thermal properties is especially important for the study of polymer composites and lithographed materials.

The fundamental feature of this technique, the SThM tip, is a nanofabricated thermal probe that can act as a resistance thermometer or a resistive heater, depending on the selected operation mode: passive mode or active mode, also known as temperature contrast mode (TCM) and (thermal) conductivity contrast mode (CCM), respectively. It is also possible to collect simultaneously surface topography image and thermal image of the samples under analysis due to the independent nature of both AFM and SThM mechanisms in the same equipment (fig. 1).

Here we present exploration routes for the study of phenomena by Scanning Thermal Microscopy. Using a XE7 Scanning Probe Microscope with Scanning Thermal Microscopy from Park Systems [2], in this presentation we show the path for research in relevant topics, namely thermal conductivity of graphene layers deposited on different substrates by conductivity contrast, the electrocaloric or magnetocaloric effects in nanostructured materials. Further work on inducing and studying structural phase transformations on thin films of functional materials with relevant properties for application in nano-devices, such as BaTiO3 and Ni2MnGa is also presented. Work in progress for this technique includes also its application to time dependent processes, bringing it forward as a contribution to otherwise complex analysis of dynamic processes.

Due to its high thermal conductivity and subsequent efficiency in heat conduction, graphene is noted as suitable candidate to aid overcome the obstacle of increasing dissipation power density arising IURP FRQVWDQW GRZQVFDOLQJ RI HOHFWURQLF GHYLFHV ,Q IDFW JUDSKHQHÂśV H[FHOOHQW WKHUPDO SURSHUWLHV combined with highly interesting electronic and optical properties, recommend it for a wide range of applications in several fields. [3.@ +RZHYHU WKH PHFKDQLVPV EHKLQG JUDSKHQHÂśV WKHUPDO SURSHUWLHV VWLOO lack clarity. It has been shown that graphene monolayers possess high thermal conductivity, but the values obtained so far seem to vary according to the deposition method and measurement technique.

SThM presents itself as a reliable technique to clarify the intriguing thermal properties of graphene monolayers (fig. 2), namely by enabling accurate estimation of the thermal conductivity of this material supported by different substrates, relying on thermal contrast between the graphene monolayer and other materials with known thermal conductivity [4].

The electrocaloric (EC) effect consists in the variation of temperature that some materials experience under an applied electric field, which is enhanced at temperatures near ferroelectric phase transitions. [5] This is why EC is becoming an interesting alternative to refrigeration based on the magnetocaloric effect due to the economically inviable large magnetic fields that this effect requires. [6 ][7] Thin films exhibit especially high EC effects. However, direct measuring of EC in thin films is hard to accomplish due to the great difference between heat flow output shown by thin film and substrate.

SThM solves this inconvenience, allowing direct measurement mapping of temperature changes in several spots of a thin film, enabling and promoting thus the search for promising materials for microscale cooling applications.

References [1] 9RO] 6HEDVWLDQ 5pPL &DUPLQDWL Microscale and Nanoscale Heat Transfer, Berlin Springer (2007) 181-236 [2] http://www.parkafm.com [3] Alexander A. Balandin, Suchismita Ghosh, Wenzhong Bao, Irene Calizo, Desalegne Teweldebrhan, Feng Miao, Chun Ning Lau, Nano Lett., 8 (2008) 902¹907 [4] Anton N. Sidorov, Daniel K. Benjamin, Christopher Foy, Appl. Phys. Lett., 103 (2013) 243103 [5] S. Kar-Narayan, S. Crossley, X. Moya, V. Kovacova, J. Abergel, A. Bontempi, N. Baier, E. Defay, N. D. Mathur, Appl. Phys. Lett., 102 (2013) 032903 [6] Dongzhi Guo, Jinsheng Gao, Ying-Ju Yu, Suresh Santhanam, Gary K. Fedder, Alan J. H. McGaughey, S. C. Yao, Appl. Phys. Lett., 105 (2014) 031906 [7] Xavier Moya, Enric Stern-Taulats, Sam Crossley, David Gonzålez-Alonso, Sohini Kar-Narayan, Antoni Planes, Lluís Maùosa, Neil D. Mathur, Advanced Materials, 25 (2013) 1360¹1365 7KLV ZRUN LV IXQGHG E\ )('(5 WKURXJK ³3URJUDPD 2SHUDFLRQDO )DFWRUHV GH &RPSHWLWLYLGDGH´ - COMPETE and by national funds through FCT - Fundação para a Ciência e Tecnologia with the projects HEAT@UA RECI/CTM-CER/0336/2012 and PEstC/CTM/LA0011/2013 (FCOMP-01-0124-FEDER-037271)

Figures

Fig. 1 Schematic showing the independent nature of both mechanisms for topographical and thermal images collection (adapted from Park Systems [2])

Fig. 2 Left: topographical image of Si/graphene interfaces performed with thermal nanoprobe of SThM system; Right: SThM conductivity contrast image (CCM) of the area depicted on the left and line profile showing the contrast in thermal conductivity between graphene and Si

The assembly of the nanoparticle-based assays with automatic flow sytems: potentialities and limitations André R.T.S. Araujoa,b, Marieta L. C. Passosa, Paula C. A. G. Pintoa, M. Lúcia M. F. S. Saraivaa a

REQUIMTE, Departamento de Química, Faculdade de Farmácia, Universidade do Porto, Rua Jorge Viterbo Ferreira nº 228, 4050-313 Porto, Portugal b Unidade de Investigação para o Desenvolvimento do Interior - Instituto Politécnico da Guarda (UDIIPG), Av. Dr. Francisco Sá Carneiro nº 50, 6300-559 Guarda, Portugal andrearaujo@ipg.pt

Abstract Nanotechnology constitutes an appealing and pursued research area which has already demonstrated its potential in numerous and varied applications. A core piece of this technology is the use of nanomaterials ranging from industrial, chemical, medical, to environmental fields. Among the nanomaterials, nanoparticles (NPs) have a number of key properties that make them particularly attractive in different formats, such as when used as quantitation tags, acting as analytical signal catalysts, in the analyte recognition and scavenging/separation, or when functionalized to carry out specific functions, especially in the biomedical field.

The idea of assembling the NPs with flow management approaches seems to be advantageous since it permits confined, precise, rigorous and reliable analysis within a shorter timeframe, besides allowing to take advantage of the particular features of the NPs, such as their unique electrical, optical and magnetic properties, high adsorption capacity and target compounds binding ability. In fact, these approaches enable a precise control of the reaction environment and of the constituent reaction steps, being adequate for the implementation of complex reactional schemes or multiparametric determinations, and guarantee that the consumption of expensive or toxic reactants is minimized and the subsequent waste generation.

This communication is intended to review the state-of-the-art of flowing stream systems comprising NPs as analytical tools, with different chemical nature, like noble metals (gold and silver), magnetic materials, carbon, silica or quantum dots. Particular emphasis will be dedicated to the categorization of the NPs-based assays in the different flow strategies, namely flow injection analysis (FIA) [1] and sequential injection analysis (SIA) [2], where the most representative applications will be selected and the main achievements and limitations will be discussed. Furthermore, it will be envisaged possible future trends of the analytical potential of NPs focusing on their use in automated flow-based approaches.

The ease of implementation of these NPs-based assays in the flow systems, by the use of readilyavailable equipment, less expensive instruments and by coupling usual detection systems found in most laboratories, and the rigorous and exquisite control of the reaction environment conditions attained in these closed systems open clearly new avenues to expand the knowledge about the NPs synthesis and reactivity and thereby to fully exploit the tremendous analytical potential of nanoparticles in conventional and novel application fields.

[1] J. Ruzicka, H. Hansen, Analytica Chimica Acta, 78 (1975) 145–157.

[2] J. Ruzicka, G.D. Marshall, Analytica Chimica Acta, 237 (1990) 329–343.

Preparation and characterization of antidot complement of square artificial spin ice I.R.B. Ribeiro,

1,2

3

1

1

1

R.C. Silva, S.O. Ferreira, W.A. Moura-Melo, A.R. Pereira and C.I.L. de Araujo

1

1

Universidade Federal de Viçosa, Dept. of Physics, 36570-900, Minas Gerais, Viçosa, Brazil Instituto Federal de Educação, Ciência e Tecnologia do Espírito Santo, Campus de Alegre, 29500000, Espírito Santo, Alegre, Brazil 3 Universidade Federal do Espírito Santo, Dept. of Physics, 29932-540, Espírito Santo, São Mateus, Brazil 2

irbribeiro@yahoo.com.br Abstract Nanomagnetism has been intensively investigated due its unusual properties and promise for possible applications ranging broadly from information storage using topological objects (vortices and skyrmions) [1-2] as well as many biological and medical applications such as magnetic separation, hyperthermia treatment, magnetic resonance contrast enhancement and drug delivery [3]. Recently, significant interest has emerged in fabricated systems that mimic the behavior of geometrically frustrated materials. Wang et al. [4] have fabricated artificial spin ice (ASI): elongated single-domain ferromagnetic nanoislands organized in regular square lattice.

Based in this geometry we fabricated a lattice of elongated holes (antidots), with the aspect ratio of 2:1 (length: width), arranged in a nickel film mimicking the geometry of the ASI system, referred to as antidot-ASI [5]. To prepare these structures on silicon (100) substrate, first was deposited a polymethyl methacrylate (PMMA) layer of 250 nm by spin coating. Then, the silicon with PMMA was dried in hotplate. Subsequently, the desired pattern was defined by e-beam lithography. After e-beam exposure and developing, the structures were transferred into the Thermionics E-Beam evaporation system where a homogeneous 25 nm nickel film was evaporated over an 8 nm titanium seed layer. The nickel was capped with 3 nm of Au to prevent oxidation of the magnetic material. The procedure was completed by lift-off process in acetone ultrasonic bath. Atomic force microscopy (AFM) image of the final sample structure are shown in Figure1.

In the hysteresis loop, obtained by Vibrating Sample Magnetometry (VSM), was made in two distinct configurations with external magnetic field applied along 0º and 45º in relation to a horizontal side. The measurements show the square-like shape of the hysteresis loop and an increase of the coercive field, when external field is applied on the sample diagonal 45º instead of aside the square pattern 0º. From micromagnetic simulations performed with computational codes provided by the Object Oriented MicroMagnetic Framework (OOMMF) [6] we found good agreement between experimental and computational hysteresis loop. So we could investigate the spin configuration in different stages of the hysteresis curve. Furthermore, these simulations revealed the existence of an array of crystal vortices (Figure 2a) with random polarization and chirality (Figure 2b).

In order to investigate the topological crystal vortex magnetization by magnetoresistive measurements were realized, with external magnetic field applied in configuration longitudinal (Figure 3a), transversal and perpendicular to the 8.1 mA applied current. The main magnetoresistive peak observed is attributed to the randomic orientation of vortex crystal polarization and chirality at zero field, causing increase in resistance due to higher density of scattering and spin mixing. The saturation of magnetization in longitudinal and transversal configuration or vortex core orientation with external field out of plane (perpendicular), providing low resistive path and consequently low resistance. It is worth mentioning that, the anisotropic behavior expected for nickel thin films can be observed just in the zoom around the curve peak (Figure 3b).

The crystal vortices pattern observed in the electrically connected propose antidote-ASI system suggest it as promising for further investigations and applications in future spintronics.

References [1] M. Rahm, J. Stah, and D. Weiss, Appl. Phys. Lett., 87 (2005) 182107.

[2] J. Iwasaki, M. Mochizuki, and N. Nagaosa, Nat. Nanotechnol., 8 (2013) 742.

[3] P. Tartaj, Encycl. Nanosc. Nanotech. 6 (2004) 823.

[4] R. F. Wang, C. Nisoli, R. S. Freitas, J. Li, W. McConville, B. J. Cooley, M. S. Lund, N. Samarth, C. Leighton, V. H. Crespi, and P. Schiffer, Nature, 439 (2006) 303.

[5] C. I. L. de Araujo, R. C. Silva, I. R. B. Ribeiro, F. S. Nascimento, J. F. Felix, S. O. Ferreira, L. A. S. Mól, W. A. Moura-Melo, and A. R. Pereira, Appl. Phys. Lett., 104 (2014) 092402.

[6] M. J. Donahue and D. G. Porter, OOMMF v1.2a3 Object Oriented MicroMagnetic Framework, Software (NIST, 2004).

Figures

Figure 1. AFM image of the antidot lattice sample that are holes and their array mimics the artificial spin ice geometry.

Figure 2. We show the results from simulation in OOMMF of 9 cells revealing the vortex-crystal chiralities in (a) and core polarizations represented by black and white central spots in (b).

(a)

(b)

18.864

18.852

18.856

Resistance ( )

Resistance ( )

18.860

18.852 18.848

18.850

18.848

18.846

18.844 18.840

-4

-2

0

2

Applied Magnetic Field (KOe)

4

18.844 -0.75

-0.50

-0.25

0.00

0.25

0.50

0.75

Applied Magnetic Field (KOe)

Figure 3. The magnetoresistive measurement with external magnetic field applied in configuration longitudinal (a) and zoom of peak (b).

Synthesis of High Effective Surface Area Silver Nanoparticles Embedded in Porous Alumina Matrix Using the Melt Spinning Process Isaac Rodríguez PÊrez, Luís Frederico Pinheiro Dick Lab. de Processos Eletroquímicos e Corrosão (ELETROCORR), Depto. de Metalurgia, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 9500, Bl. IV-75, 91501-970, Porto Alegre, Brazil isaac.rp@gmail.com, lfdick@ufrgs.br Abstract One of the most relevant uses for the Ag NPs (nanoparticles) is their application on the industry as catalytic material [1, 2]. The catalytic activity of the Ag NPs directly depends on the particle sizes and their distribution [3]. The chemical reduction approach is considered as the most appropriate technique to produce large quantities of nanoparticles with controlled size [4, 5]. Hence, is important to understand that this method uses reactants that can provoke potential risks for the environment and health [5]. The porous anodization of aluminum followed by electrodeposition is a well-known process to obtain metal nanoparticles or nanowires of noble metals as silver [6¹8].

In the present work, we developed a new route for the fabrication of Ag nanoparticles embedded in a dielectric matrix (alumina) by the two-step porous anodization of a thermally treated (quenched) alloy using the melt spinner technique. A pro-eutectic Al-Ag alloy (95.25 %wt. Al) was molten and gradually heated to 780 °C using an induction oven and kept at that temperature for 20 minutes before quenching in the melt spinner. Then, a porous anodization process was performed in order to obtain a highly ordered nanotube array. The anodization was performed in 0.3 M oxalic acid solution applying a current -2 density of 50 mV¡cm for 15 minutes. The structure and morphology of the aluminum oxide with precipitated silver were characterized by Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM).

Fig. 1A shows the SEM image of the surface of the anodized sample evidencing the presence of eutectic Ag in a lamellar structure alongside Ag NPs with a mean diameter of 100 nm on top of the aluminum oxide layer. The cross-section (Fig. 1B) shows that the Al2O3 nanotubes formed during the anodization are 9.7 Âľm long and 200 nm wide, with incrusted Ag NPs on the regular nanotubular layer.

The aluminum oxide layer was physically separate by stripping and characterized by TEM. Fig. 2A shows a typical formed nanotube with a mean diameter of 200 nm. On top of the nanotube Ag NPs are present with a diameter varying from 7 to 18 nm. The TEM/EDS elemental composition analysis that was performed (Fig. % WKH VSHFWUD RI WKH VXUIDFH PDUNHG DV ³,œ VKRZV WKDW LW LV IRUPHG RI $O-Ag, ZKLOH WKH QDQRSDUWLFOHV PDUNHG DV ³,,´ contain 99 %at. of silver. The size distribution of the Ag NPs determined by TEM imaging of the surface (Fig. 3A) showed that 95% of the Ag NPs have equivalent diameters smaller than 40 nm, ranging the diameters between 4 and 87 nm, as seen in the histogram of Fig. 3B. Moreover, it is noteworthy that 50% of the nanoparticles have an equivalent diameter between 4 and 10 nm. Consequently, it is confirmed that by a new route evolving porous anodization Ag NPs with sizes ranging between 4 and 87 nm can be produced randomly dispersed on a porous aluminum oxide surface.

References [1] McFarland AD, Van Duyne, RP, Nano Letters, 3 (2003) 1057-1062.

[2] KĂśhler JM, Abahmane L, Wagner J, Albert J, Mayer G, Chemical Engineering Science, 63 (2008) 5048-5055.

[3] Zhang J, Chen P, Sun C, Hu X, Applied Catalysis A: General, 266 (2004) 49-54.

[4] Leopold N, Lendl BA, The Journal of Physical Chemistry B, 107 (2003) 5723-5727.

[5] Zhang W, Qiao X, Chen J, Materials Science and Engineering: B, 142 (2007) 1-15.

[6] Huber CA, Huber TE, Sadoqi M, Lubin JA, Manalis S, Prater CB, Science, 263 (1994) 5048-5055.

[7] Yi JB, Pan H, Lin JY, Ding J, Feng YP, Thongmee S, Liu T, Gong H, Wang L, Advanced Materials, 20 (2008) 1170-1174.

[8] Zhang J, Kielbasa JE, Carroll DL, Materials Chemistry and Physics, 122 (2010) 295-300.

Figures

Figure 1. (A) SEM image of the oxide surface containing Ag NPs. (B) Cross-section SEM image of formed Al2O3 nanotubes.

Figure 2. (A) TEM image of formed Al 2O3 nanotubes with embedded silver nanoparticles. (B) TEM image of nanotube showing the areas of EDS analysis. The insert shows the obtained spectra.

Figure 3. (A) Area selected for the distribution analysis by TEM and (B) histogram of the frequency per area versus the equivalent diameter of the silver nanoparticles and the cumulative probability.

Resistive switching and impedance spectroscopy in metal-oxide-metal trilayers with SiOx and ZrO2: a comparative study a

b

b

b

b

b

C.M.M. RosĂĄrio , O.N. Gorshkov , A. Kasatkin , I. Antonov , D. Korolev , A.N. Mikhaylov , a,c N.A. Sobolev a

c

Departamento de Física and I3N, Universidade de Aveiro, 3810-193 Portugal b Lobachevsky State University of Nizhni Novgorod, 603950 Russia 1DWLRQDO 8QLYHUVLW\ RI 6FLHQFH DQG 7HFKQRORJ\ ³0,6L6´ 0RVFRZ 5XVVLD cmiguelrosario@ua.pt

Abstract The ReRAM, acronym of resistive (switching) random access memories, are candidates to lead the new generation of non-volatile memories and are based on a phenomenon known as resistive switching (RS) [1]. The research on this SKHQRPHQRQ NQRZQ VLQFH WKH ÂśV [2], was boosted by the link to the memristor, a passive fundamental circuit element proposed by Leon Chua in 1971 [3], demonstrated by a group of the HP Labs in 2008 [4]. Although the titanium dioxide is considered a prototypical memristive material [5], research on RS in structures containing materials that are compatible with the CMOS technology, nowadays the leading technology in the fabrication of integrated circuits, such as silicon oxide or zirconium oxide, may favour the future market introduction of RS-based devices.

In this work, Au/oxide/TiN structures, obtained by RF-magnetron sputtering deposition of 40 nm thin films of silicon and zirconium oxides, were investigated by means of current-voltage (I-V) characteristics and impedance spectroscopy and compared based on the results obtained.

In the SiOx structure, the I-V characteristics exhibit bipolar-like RS, with a ratio between the 2 resistances of the high resistance state (HRS) and the low resistance state (LRS) bigger than 10 , at 1 V read voltage. The observed RS is sensitive to the Au electrode exposure to the atmosphere, which enhances the RS (see Fig. 1). A decrease in the voltage application time leads to an increase in the voltage required to induce the transition from HRS to LRS. The two different states show a very distinct behaviour as the temperature is varied: whereas the LRS's resistance has a very weak temperature dependence and decreases with decreasing temperature, in the HRS the resistance increases as the temperature drops. The latter state's resistance temperature dependence is described by a thermal activation of charge carriers, with activation energies of 0.46 and 4.3 meV in the 6 to 130 K temperature region. The weak dependence of the resistance with the Au electrode area and the invariance of the structure's capacitance between the states suggest a filamentary mechanism for the observed RS. Due to the oxygen's influence on the RS, the creation and disruption of the filaments should involve redox reactions.

2 The ZrO2 structures also exhibit bipolar-like RS, with a ratio of ca. 10 between the resistance of the HRS and of the LRS, read at 1 V. However, the atmospheric exposure decreases the above mentioned ratio, having the opposite effect on the RS, relatively to the SiOx case (see Fig. 2). The increase in this ratio via pulsed measurements evidences the existence of at least two competing processes in the RS. The impedance spectra show a similar behaviour between these structures and the SiOx ones, even though there is a bigger dependence on the electrode area, behaviour that deviates from a single filament model. The addition of a germanium oxide (GeO x) layer between the Au electrode and the ZrO2 film enhances the repeatability of the I-V characteristics.

References [1] D. S. Jeong, R. Thomas, R. S. Katiyar, J. F. Scott, H. Kohlstedt, A. Petraru, C. S. Hwang, Rep. Prog.

Phys., 75 (2012): 076502.

[2] T. W. Hickmott, J. Appl. Phys., 33 (1962): 2669Âą2682.

[3] L. Chua, IEEE Trans. circuit theory, CT-18 (1971): 507 Âą 519.

[4] D. B. Strukov, G. S. Snider, D. R. Stewart, R. S. Williams, Nature, 453 (2008): 80Âą83.

[5] K. Szot, M. Rogala, W. Speier, Z. Klusek, A. Besmehn, R. Waser, Nanotechnology, 22 (2011): 254001.

Figures

10-1 LRS RESET

10-2 10-3

~I~ (A)

10-4

SET

10-5 10

HRS

-6

10-7 Without SiO2 mask

10-8

With SiO2 mask

Initial direction

10-9 -6

-4

-2

0

2

4

6

V (V) Fig. 1: Typical I-V characteristics obtained for the Au/SiOx/TiN structures with a voltage sweep rate of ca. 1 V/s. The data displayed with the empty symbols was measured with a 300 nm-SiO2 mask covering the Au electrode, evidencing the importance of the atmospheric exposure for the RS process in increasing the resistance ratio between the high resistance state (HRS) and the low resistance state (LRS). The red dashed arrow indicates the initial direction of measurement.

10-1 10-2 10

LRS

RES E

T

-3

~I~ (A)

10-4 10-5 10

HRS

SET

-6

10-7

Without SiO2 mask (cont.)

10-8

With SiO2 mask (cont.)

Initial direction

Without SiO2 mask (puls.)

10-9 -6

-4

-2

0

2

4

6

V (V) Fig. 2: Typical I-V characteristics obtained for the Au/ZrO2/TiN structures with a voltage sweep rate of ca. 1 V/s (for the data shown with the circular symbols). The data displayed with the empty symbols was measured with a 300 nm-SiO2 mask covering the Au electrode, evidencing the impact of the atmospheric exposure for the RS process, in this case decreasing the resistance ratio between the high resistance state (HRS) and the low resistance state (LRS). The data displayed with the triangular symbols were measured in a pulsed regime (with a voltage sweep with 500 Č?s pulses for each voltage level, intercalated with a time interval where there was no applied voltage), which enabled a higher resistance ratio even without the mask. The red dashed arrow indicates the initial direction of measurement.

Nanoencapsulation improves the antibactericidal effect of docosahexaenoic acid against Helicobacter pylori Catarina L. Seabra1,2,3,4, Cláudia Nunes5, Marta Correia1,3, José Carlos Machado1,3,6, Celso Albuquerque Reis1,3,4,6, Inês C. Gonçalves1,2, Salette Reis5, M Cristina L Martins1,2,3 1

Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Portugal, 2INEB - Instituto de Engenharia Biomédica,

Universidade do Porto, Portugal, 3IPATIMUP ± Instituo de Patologia e Imunologia Molecular da Universidade do Porto, Portugal, 4

ICBAS- Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Portugal, 5REQUIMTE, Laboratório de Química Aplicada, Faculdade de Farmácia, Universidade do Porto, Portugal, 6Faculdade de Medicina, Universidade do Porto, Portugal catarina.seabra@ineb.up.pt

Abstract Introduction Helicobacter pylori (H. pylori) is a gram-negative, microaerophilic and spiral-shaped bacterium WKDW FRORQL]HV WKH JDVWULF PXFRVD RI RYHU RI WKH :RUOG¶V SRSXODWLRQ > @ H. pylori infection recommended treatment is based in a combination of at least two antibiotics and a proton pump inhibitor [2]. However, this therapy fails in 20% of patients especially due to bacterial resistance [3].

It was previously demonstrated that a lipophilic compound, docosahexaenoic acid (DHA), an omega-3 polyunsaturated fatty acid present in fish oil, decreases H. pylori growth in vitro in a dosedependent way and inhibits mice gastric colonization in vivo. However, up to 40% of infected mice, following DHA treatment, are still colonized by bacteria [4]. This might be explained by the low penetration of DHA through the stomach mucus layer, which leads to an insufficient concentration of DHA to eradicate H. pylori at the infection site. This work aims the development of a DHA gastric delivery system to improve its efficacy against H. pylori.

Materials & Methods DHA was incorporated into nanostructured lipid carriers (NLC), submicron colloidal carriers composed of biodegradable and biocompatible lipids recognized for the incorporation of lipophilic and poorly water-soluble drugs [5]. NLCs with different DHA concentrations (0, 1, 2 and 2.5% v/v) were produced by hot homogenization technique using a mixture of mono-,di- and triglyceryl esters of palmitic and stearic acids as solid lipids, a liquid lipid and polysorbate 60 as the stabilizer. NLCs, with and without DHA, were characterized by dynamic light scattering (DLS) in Milli-Q water at 37ºC, and DHA incorporation was quantified using UV-Vis spectroscopy (200-400nm) after dissolution in ethanol.

The effect of DHA-NLC on H. pylori J99 strain growth was evaluated during 24h, at 37ºC, 150 rpm, under microaerophilic conditions using an initial bacteria concentration of ~1x107 bacteria/ml in Brucella Broth medium (BB) supplemented with 10% of Fetal Bovine Serum (FBS). Different concentrations of DHA-NLCs (50, 100 and 500 µM) prepared with 2% v/v DHA were tested. DHA in solution and NLCs without DHA were used as control. After different time-points, a sample of each

bacterial culture was collected and plated on H. pylori selective solid medium. Number of viable bacteria was determined by colony forming units (CFU) counting.

Cytotoxicity of DHA-NLCs towards MKN45 gastric carcinoma cell line was performed using 3(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl tetrazolium bromide (MTT) and lactate dehydrogenase leakage (LDH) assays. MKN45 cells were seeded in concentration of 5x105 cells per well in RPMI 1640 with glutamax and HEPES, supplemented with 10% inactivated FBS and 1% PenStrep at 37ºC in humidified 5% CO2 atmosphere, during 48h. Then, different concentrations of NLCs and DHANLCs (10, 25, 50 and 100 µM), prepared with 2% v/v DHA were added to 2 ml of final volume. After 24h, LDH and MTT assay were performed by measuring optical density at 490 and 630 nm and at 590 and 630 nm, respectively, using a microplate reader.

Results All produced NLCs have a size of 150-250 nm, negative zeta potential (~ -30 mV) and a DHA entrapment efficiency higher than 50% independently on DHA amount added.

Experiments performed with H. pylori demonstrated that NLCs without DHA have a bacteriostatic effect, inhibiting bacterial growth, whereas all concentrations of DHA-NLC tested are bactericidal against H. pylori even at the lower DHA concentration used (50 µM) in opposite to DHA in solution that could not kill bacteria at concentrations lower than 100 µM. Cytotoxicity studies revealed that all NLCs tested (with and without DHA) are non-cytotoxic for gastric cells at concentrations up to 50 µM.

Conclusion In conclusion, NLCs nanoparticles can be used to encapsulate DHA improving its bactericidal effect on H. pylori. These nanoparticles are not cytotoxic against gastric cells at bactericidal concentrations. DHA-loaded NLC should therefore be considered as an alternative to the current treatment of H. pylori.

References [1] Wroblewski et al.; Microbiol Rev; 23 (2010):713-39 [2] Malfertheiner et al.; Gut; 61 (2012):646-64 [3] Vakil; Am J Gastroenterol; 101 (2006):497-9 [4] Correia et al.; PLoS One; 7 (2012): e35072 [5] Battaglia & Gallarate; Expert Opin Drug Deliv; 9 (2012): 497-8

An Improved Wet Chemical Approach For The Separation Of Graphene From Nickel Foil To The Reutilization Of Catalyst

a,b

a

c

b

Choon-Ming Seah , Brigitte Vigolo , Siang-Piao Chai , Abdul Rahman Mohamed .

a b

Institut Jean Lamour, CNRS-UniversitÊ de Lorraine %3 9DQG°XYUH-lès-Nancy, France

School of Chemical Engineering, Engineering Campus, Universiti Sains Malaysia, 14300 Nibong Tebal, Seberang Perai Selatan, P. Pinang, Malaysia c

Chemical Engineering Discipline, School of Engineering, Monash University, Jalan Lagoon Selatan, 46150 Bandar Sunway, Selangor, Malaysia Email: seahchoonming@yahoo.com

Abstract Chemical Vapor Deposition (CVD) is the most widely studied approach for the synthesis of wafer scale graphene. To fully utilize the magnificent properties of the graphene, the separation of graphene from the metal catalyst is important. To date, majority of the studies utilizing the wet chemical etching method that scarifying the metal catalyst in order to obtain free standing graphene. In order to realize the re-use of catalyst for minimization of the waste, an improved simple wet chemical etching method approach is proposed. Nickel has relatively high carbon solubility under elevated temperature as compared with other catalyst. Part of the carbon dissolved in the bulk nickel was not been used for the formation of graphene and later reacted with nickel to form nickel carbide crystal. After CVD, the nickel foil with graphene was 3 floated onto iron nitrate solution with concentration of 1 mol/dm , an etching agent. The etching agent would intercalate between graphene and nickel to etch the surface of nickel for separation under slower rate. The inertness of nickel carbide would act as the protective layer to slowdown the chemical attack onto the bulk nickel foil and preserve it. The remaining nickel foil after the separation was used for same CVD and separation process to obtain another layer of graphene. A nickel foil with a thickness of 125Âľm can be reused to synthesis up to 6 pieces of graphene without large deviation in properties.

Large power emission in MTJ based spin torque nano-oscillators using a free layer near the in-plane to out-of plane transition M. Tarequzzaman, J. D. Costa, J. Borme, M. Gonzalez-Debs, B. Lacoste, E. Paz, S. Serrano-Guisan, R. Ferreira and P. Freitas.

INL-International Iberian Nanotechnology Laboratory, Avenida Mestre Jose Veiga, 4715-330, Braga, Portugal tareq.zaman@inl.int

Spin torque nano-oscillator (STNO) explore dynamic magnetic effects induced in the free layer of magnetoresistive devices induced by spin polarized currents. Soon after its discovery, STNO draw much attention to the researchers because of its advantages over conventional CMOS oscillators. The advantage of STNO covers, simple structure, smaller footprint (<200nm), high frequency tunability, large frequency (2-20 GHz range oscillations depending on magnetic field), low cost and good compatibility with the standard complementary metal oxide semiconductor (CMOS) technology.[1-3]However several challenges need to be addressed before STNOs are to be used in practical purpose. As it has critical disadvantages in terms of lower output power and relatively large linewidth in comparison with voltage controlled oscillators (VCOs).[4] The power generation of STNO depends on several factors; resistance change induced by the magnetoresistance (MR) effect in the magnetization oscillations is one of them. Therefore, MgO based magnetic tunnel junctions (MTJs) with higher MR ratio (>50%) deliver larger microwave signals than metallic oscillators with lower MR ratio (<10%).[3] In addition to this, another requirement for a large power emission is the excitation of large-amplitude oscillations. To this end, several configurations for the magnetization of the free and pinned layer have been proposed.

In this work, MTJ stacks (50 Ta/ X CoFe40B20/MgO [3.0 Ohm-µm2]/2.2 CoFe40B20/0.85 Ru/2.0 CoFe30/20 IrMn (Thickness in nanometer) with an MgO barriers have been deposited using a Singulus TIMARIS PVD system. The free layer thickness (X) was changed between 2.0nm (free layer magnetization in plane) down to 1.0nm (free layer magnetization perpendicular to plane). These stacks were then patterned into nanopillars with different shapes (circular and elliptical) and dimension (50 nm to 200 nm in diameter) by electron beam lithography and ion milling technique.

The nano-pillars have been measured in a radio frequency transport measurement setup at room temperature. It is found that a large power output with a small linewidth is obtained in nano-pillars with a free layer thickness of 1.4nm which still have an in-plane magnetization but right at the transition to outof-plane magnetization, i.e., the in-plane free layer experiences a very strong perpendicular anisotropy contribution.

An example of such measurements is shown in Fig. 1.a. for a pillar with circular shape and 150nm diameter. The result, show in Fig. 2, displays microwave signals with maximum power of 300 nW and narrow linewidth as small as 30 MHz. These STNOs operate with frequencies in the range between 2.42.8GHz .The large power output and narrow linewidth of these nano-oscillators make them good candidates for integration with CMOS circuits such as new generation Phase-Locked-Loops (PLLs).

References: [1] Z. Zeng, G. Finocchio, B. Zhang, P. K. Amiri, J. A. Katine, I. N: Krivorotov, Y. Huai, J. Langer, B. Azzerboni, K. L. Wang, and H. Jiang, Sci. Rep. 3, (2013) 1426 [2] S. I. Kiselev, J. C. Sankey, I. N. Krivorotov, N. C. Emley, R. J. Schoelkopf, R. A. Burman, D. C. Ralph, Nature.

425, (2003), 380±383.

[3] Z. Zeng, P. K. Amiri, I. N. Krivorotov, H. Zhao, G. Finocchio, J.-P. Wang, J. A. Katine, Y. Huai, J. Langer, O. K Galatsis, K. L. Wang, and H. Jiang, ACS Nano 6, (2012) 6115±6121 [4] H. S. Choi, S. Y. Kang, S. J. Cho, I. Y. Oh, M. Shin, H. Park, C. Jang, B. C. Min, S. Kim, S.Y. Park, C. S. Park, Sci. Rep. 4, (2014) 5486

a)

b)

RA ~ 3 : Pm2 Circular 150 x 150 nm2 FL thickness ~ 1.4 nm

Figure1: a) Illustration of radio frequency (RF) measurement setup. b) The measured MTJ stack and nanopillar dimension.

400 easy axis

380

Ibias = +1.25 mA

360 2.8

PSD (PV2/Hz)

350

P

R (:)

4

2.4 400 200

R (:) :

c)

f (GHz)

b)

* (MHz) *

a)

Ibias = -1.25 mA

-1

0 Field (A)

1

150

x10

0

0 2

4 6 f (GHz)

8

-2

-1 0 1 Ibias (mA)

P (nW)

300

hard axis

2

Figure2: a) Transport measurement (two contact measurement) in easy and hard axis. The arrow indicating the RF measurement point b) Microwave emission spectra measured in positive bias currents (Black spectrum) and negative bias currents (Red Spectrum). c) Shows the results, in terms of power emissions, linewidth, frequency tunability and resistance.

Spin-orbit coupling in graphynes Guido van Miert, Cristiane Morais Smith, and Vladimir Juricic Institute for Theoretical Physics, Utrecht University, Leuvenlaan 4, Utrecht, The Netherlands G.C.P.van.Miert@gmail.com Abstract Graphynes represent an emerging family of two-dimensional carbon allotropes that recently attracted much interest due to the tunability of the Dirac cones in the band structure. We explore the effects of spin-orbit couplings, both Rashba and intrinsic ones, in these systems. First, we develop a general method to address spinorbit couplings within tight-binding theory. We then apply this method to describe the effects of spin-orbit couplings in , , and -graphyne. We show how spin-orbit couplings can lead to various effects related to both topological and non-topological properties of their band structures. In -graphyne, as in graphene, the Rashba spin-orbit coupling splits each Dirac cone into four, whereas the intrinsic spin-orbit coupling opens a topological gap. In -graphyne, intrinsic spin-orbit coupling yields high- and tunable Chern-number bands, which may host both topological and Chern insulators, in the presence and absence of time-reversal symmetry, respectively [1]. On the other hand, Rashba spin-orbit coupling can be used to control the position and the number of Dirac cones in the Brillouin zone. Finally, the Rashba spin-orbit coupling can close the band gap in -graphyne [2].

References [1] G. van Miert, C. Morais Smith, and V. Juricic, Phys. Rev. B. 90, 081406(R) (2014).

[2] G. van Miert, V. Juricic, and C. Morais Smith, arXiv:1409.0388 (Accepted into Phys. Rev. B)

Synthesis and characterisation of graphite oxide/vanadate nanowire composites 1

1

7DPiV 9DUJD, Henrik Haspel, Ă&#x2C6;NRV .XNRYHF]

1,2

=ROWiQ .yQ\D

1,2,3

1

Department of Applied and Environmental Chemistry, University of Szeged, 5HUULFK %pOD WpU , H-6720 Szeged, Hungary MTA-6=7( ¾¾/HQG OHWœœ 3RURXV 1DQRFRPSRVLWHV 5HVHDUFK *URXS 5HUULFK %pOD WpU H-6720 Szeged, Hungary 3 MTA-6=7( 5HDFWLRQ .LQHWLFV DQG 6XUIDFH &KHPLVWU\ 5HVHDUFK *URXS 5HUULFK %pOD WpU H-6720 Szeged, Hungary konya@chem.u-szeged.hu

2

Abstract There is a growing interest in composites composed of vanadium-oxides and carbon nanostructures due to their promising electrochemical properties. These composite materials are potential candidates for application as electrode materials in Li-ion batteries and supercapacitors [1,2].

The latter have thousand times higher specific capacity than conventional electrolytic capacitors, while its performance deteriorates only slightly during hundreds of charge-discharge cycles.

In our study vanadate nanowire Âą graphite oxide composites were synthesized via the hydrothermal route. The influence of adding graphite oxide to the composite on the electrochemical performances was investigated. The morphology, structure and interaction between components were studied by transmission and scanning electron microscopy (TEM, SEM), Raman spectroscopy, X-ray diffractometry (XRD) and energy dispersive X-ray spectrometry (EDS). The electrochemical properties were examined by the galvanostatic charge-discharge method, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The specific capacity, energy and power density of the capacitor constructed from the vanadate/graphite oxide composites were determined and their dependence on the amount of added graphite oxide was discussed.

Results revealed that a hybrid type supercapacitor was formed. The specific capacities determined from cyclic voltammetry and galvanostatic charge-discharge method were in good agreement and were found to increase monotonously between 210 and 270 F/g with increasing amount of graphite oxide. The energy density of the capacitor changed from 19 to 25 Wh/kg with the graphite oxide content, however, power density turned out to be independent of the graphite oxide amount at around 410 W/kg. These values are in good agreement with literature data. On the other hand, the mechanism responsible for the considerable deterioration of specific capacity during repeated chargedischarge cycles is yet to be resolved.

References [1] Bonsoa, J.S.; Rahya, A.; Pereraa, S. D.; Nourb, N.; Seitz, O.; Chabalb, Y.J.; Balkus Jr., K.J.; Ferraris, J.P.; Yang, D.J. J. Power Sources, 203 (2012) 227Âą232.

[2] Liang, S.; Zhou, J., Fang, G.; Zhang, C.; Wu, J.; Tang, Y.; Pan, A. Electrochim. Acta 130 (2014) 119Âą126.

XPS and VUV studies of N-doped TiO2 Sol-Gel Films H. C. Vasconcelos

1,2

and F. Rivera-López

1

2

Azores University, Department of Science Technologies and Development, Campus de Ponta Delgada, PT - 9501-801 (Ponta Delgada), Açores, Portugal CEFITEC - Centre of Physics and Technological Research, Physics Department of FCT/UNL, Quinta da Torre, 2829-516 Caparica, Portugal 3 Department of Fundamental and Experimental Physics, Electronics and Systems, University of La Laguna, Tenerife 38206, Spain Corresponding author: H.C. Vasconcelos (Tel.: +351 296 650 170), email: hcsv@uac.pt

Information about the structural environment of nitrogen anions in TiO 2 host matrices is necessary in order to tailor a glass composition with optimized spectral properties for photocatalytic applications.

The present study is aimed at determining the influence of the N ions on the structural glass environment around Ti cations in amorphous TiO2 matrices (oxynitride films). For this purpose, thin film samples of TiO2-xNx compositions, with N concentrations up to x = 0,75 (25 at.%), were prepared by sol-gel processing followed by spin-coating onto Si(100) wafers, glass slides and CaF2 substrates.

The samples were then studied by X-ray photoemission spectroscopy (XPS) and Vacuum ultraviolet (VUV) light scattering, after being annealed up to 500°C. These measurements allowed the determination of the concentrations of the different Ti-O-Ti, N-Ti-O and Ti-N-Ti bonding sequences.

XPS data were correlated to thermal behavior and optical properties. Photoabsorption spectra of oxynitride thin films are reported in the energy range 3.9±10.8 eV (320±115 nm). Electronic state assignments have been suggested for each of the observed absorption bands.

! " # $ %" &! " ' % "

() ' & "

" * + #! % "

!"

# ! % % " ,% ! " ,% % % # - ! " ,%- $ ! ! . % # ! - ! %-* / / " ! " 01 23 " ! - ! ! ! ! ,% % 45&'6 " ! " 0(3 7 ! ! ! 8. ! % % % ! ! 5&' " ! - % " 4# 6 "" ! " 9% " %" ! ! - ! % # # ! 5&' # ! / " # " ! % % " ! # % - " %"" . " % ! ! " ! " % ! %#! ! - ! ! 8. ! ! 5&' # - % - " # ! / " " # ! # # ! 5&' ! ! ! - / " ! * ! : " # - " ! ! ! # " 7 # ! ; % ! " - "" ; ! % % " % " " " " % ! " ! % ! ! ! 8. ! % % " ! % < ! . " % * ! % ! % % % " % ! %#! " ! # 7 ! ! % # ! % - ! ! % % - ! - % ! " ! % * ! # $ % 013 & *

" " &! = 1)2 42)1(6 2>2>11 023 ? & $ " ' % @ &! ? = AB 42))26 2CCC)2 0(3 $ " @ 8% $ " # ! &! ? = 1)2 42))B6 11CA)2

! &

!

! - % - ! D " ' & " % # EF'.

2)11G)(G G (G))2>)

Cover image: p-Type Cu2O colloids optimized for photoelectrochemistry and electronics Credit: Yury V. Kolenâ&#x20AC;&#x2122;ko (International Iberian Nanotechnology Laboratory -INL, Portugal)

Edited by Phantoms Foundation Alfonso Gomez 17 28037 Madrid - Spain info@phantomsnet.net www.phantomsnet.net Deposito legal / Spanish Legal Deposit: BI-168-2015

www.nanopt.org

Edited by

Phantoms Foundation Alfonso Gomez 17 28037 Madrid - Spain info@phantomsnet.net www.phantomsnet.net