Green Synthesis of Silver nanoparticles using Ocimum sanctum (Tulsi) leaf extract and evaluation of their antimicrobial activities Jagpreet Singh1, Lovepreet Singh1 , Rajat Bajaj1 , Amandeep Singh Batth1,Mohit Rawat 1* , 1
Department of Nanotechnology, Sri Guru Granth Sahib World University(Punjab) Email id: mohitnano.nit@gmail.com
Abstract There is an increasing demand of silver nanoparticles due to their unique properties and applications in various fields such as medicine, catalysis, nanoelectronics, textile field, pollution and water treatment. Nanosilver strong antimicrobial activity is the major reason for the development of nanosilver containing products. The silver nanoparticles are synthesis by various chemical and physical methods. The major drawbacks of chemical and physical methods are the synthesis processes are expensive and many toxic chemicals are used. To overcome these problems Green Nanotechnology comes to play very crucial role for synthesis of silver nanoparticles. Use of various plant for synthesis of biogenic silver nanoparticles referred as Green Nanotechnology. In the present study ,we reported the green synthesis of silver nanoparticles using by Ocimum sanctum (Tulsi) leaf extract in the exposure direct sunlight atmosphere without using any chemical additive . The Ocimum sanctum (Tulsi) leaf extract act as reducing agent as well as capping agent.Developed Ag nanoparticles were duly characterized and tested for their antibacterial activity. The formation of silver nanoparticles was observed by the change of colour from colourless to brown by the addition of Ocimum sanctum (Tulsi). UV-Vis absorption spectroscopy was used to monitor the quantitative formation of silver nanoparticles . FTIR analysis revealed that the AgNPs were stabilized by eugenols, terpenes, and other aromatic compounds present in the extractAntimicrobial activity of the silver bio-nanoparticles was performed by a well diffusion method. The morophology of the Silver Nanoparticles study by Scanning Electron Microscopy .
Introduction
a)
b)
a)
Silver has been valued throughout history for many of its properties that are useful to humans. One of the most beneficial uses of silver has been as a potent antibacterial agent that is toxic to fungi, viruses and algae. The major phytochemicals present in O. sanctum plant eugenol, β-caryophyllene, β-elemene, cyclopropylidene, carvacrol, linalool, germacrene, etc. These chemical constituents are supposed to be responsible for bioreduction of silver metal ions followed by stabilization of the nanoparticles formed.
Why Green Synthesis? Synthesized from chemicals
Chemical
Sodium Borohydride
Noncompatible
Use costly chemicals
Green
Organic material
Compatible
a)
b)
b)
Waste material
Safe
Toxic
Fig 1:Uv results of Ag NPs (a) at different condition (b) with different concentration of tulsi extract
Use Plant extract or fruits
Cheap
Expensive
Methodology Tulsi Leafs
b)
Fig 3: (a) Uv and (b) FTIR of Ag NPS with 3ml Tulsi extract
Tulsi Extarct
Fig 4: (a) Uv and (b) FTIR of Tulsi Extract
c)
hv
Silver Nitrate + Tulsi Extarct in sunlight atmosphere d)
Biogenic Silver Nanoparticles
Fig 5: FESEM of Silver Nanoparticles (Ag NPs)
Fig 2: Zetasizer of Ag NPs with (a) 1ml,(b) 2ml and (c)3ml and(d) 5ml of tulsi extract respectively
Antimicrobial Chart a b
2 1.5
d
e f
1
g
h
i
c
Results
0.5 0 5μl Ag 10μl Ag 15μl Ag 20μl Ag 25μl Ag 30μl Ag NPs NPs NPs NPs NPs NPs
Fig 6: Plates showing diameters of zones of inhibition of E. coli. (gram +ve) bacteria (a) Tulsi extract,b)AgNO3 c)water, d)5μl, e)10μl, f)15μl, g)20μl, h)25μl and i) 30μl silver NPs
a) Conclusion We have developed a very simple, efficient, and robust practical method for the synthesis of silver rnanoparticles using aqueous leaf extract of O. Sanctum (Tulsi) as both reducing and capping agent.. Investigation on the antibacterial activity of AgNPs against E. coli and reveals high potential of Tulsi extract stabilized AgNPs to be used as antimicrobial agent in medical field as well as food and cosmetic industries.
.Acknowledgement In performing our project , we had to take the help and guideline of some respected persons, who deserve our greatest gratitude. The completion of this project gives us much pleasure. We would like to show our gratitude Assistant Prof. Mohit Rawat,,Department of nanotechnology, SGGSWU ,for giving us a good guideline for a project throughout numerous consultations. We would also like to expand our deepest gratitude to Dept..Biotechnology.SSGWU, which provided us required facilities for our project. References:1)Mittal AK, Chisti Y, Banerjee UC (2013) Synthesis of metallic nanoparticles using plant extracts. Biotechnol Adv 31:346–356 2) A. Leela and M. Vivekanandan, “Tapping the unexploited plant resources for the synthesis of silver nanoparticles,” African Journal of Biotechnology, vol. 7, no. 17, pp. 3162–3165, 2008. 3) S. S. Shankar, A. Rai, A. Ahmad, and M. Sastry, “Rapid synthesis of Au, Ag, and bimetallic Au core-Ag shell nanoparticles using Neem (Azadirachta indica) leaf broth,” Journal of Colloid and Interface Science, vol. 275, no. 2, pp. 496–502, 2004