AMPHIPHILIC SILICA NANOPARTICLE POWDERS FOR IMAGING OF LATENT FINGERPRINT WITH SIMULTANEOUS IDENTIFICATION OF EXPLOSIVE TRACES Sagar Bhowmik*, Prasenjit Maity* *Institute of Research and Development, Gujarat Forensic Sciences University, Gandginagar - 382007 Abstract: Poly-Nitro-Aromatic molecules, e.g., DNT, TNP and (most importantly) TNT, are widely used as explosives by several terrorist groups and separatist organizations with the sole intention of mass killing. From an industry point, such materials are also extensively used in crude oil extraction, mining industries, by road and transport authorities for making tunnels, railroads, highways through mountainous regions, etc. Hence, security measures for usage, manufacture, handling, storage, transport and supply-consumption, etc. need to be strictly regulated. Despite such regulation, there have been number of incidents endangering human life since these range of materials are highly effective in small quantities too. Thus, it is of more and more importance to governments and security companies to identify their presence from common public even if found in trace quantities[1].
Earlier Work: • We worked on π-electron-rich complexes for sensing various electron deficient nitroaromatic explosives [NT, DNT, TNT and TNP].
We presented detection in aqueous, non-aqueous phases, as well as in the solid state as a paper strip with maximum detection limit of 10−9 M [2]
Present Work:
Charaterization:
• In our recent work, we have used silica surface as a substrate for such detection and upto trace level presence of nitroaromatics. • We have optimized the amphiphilicity of silica nano powders by modifying hydrophilic silica surface with different alkyl (-C5H11, -C11H23 and -C17H35) chains for maximizing its efficacy for detection and sensing applications.
Modified Scheme:
Base Scheme:
Advantages: Detection and sensing by using silica based nanomaterials is many folds advantageous due to its synthetic simplicity, low cost, high surface area and easy tailoring the surface character.
Sensing of Nitroaromatics in Solution and Solid Phase: Imaging:
Summary: This electron rich luminescent dye molecule can also detect trinitrotoluene (TNT) through photoinduced electron transfer process (PET). We demonstrated that this Pt(II)-dye functionalized amphiphilic and luminescent silica powder could be used for development of latent fingerprint and simultaneously can identify nitroaromatic explosives if present in the print. The work thus reports a new approach for the development of nanopowders for development of latent prints and identifying nitroaromatic explosives also in such materials [communicated]
References: 1. Optical chemosensors and reagents to detect explosives; Chem. Soc. Rev. 2012, 41, 1261−1296 2. Pt(II)C∧N∧N-Based Luminophore−Micelle Adducts for Sensing Nitroaromatic Explosive; Langmuir, 2017, 33 (17), pp 4291–4300