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, Gandhinagar –
Development of latent fingerprint with silica nanopowder is strategically beneficial due to its synthetic simplicity, low production cost, high surface area and easy tailoring of surface phenomena. However, it is necessary to optimize the surface amphiphilicity of silica nanoparticle for its use in powder dusting method. In our present work, we demonstrated the tuning of amphiphilicity of silica nanopowders (average size 35±5 nm) by modifying hydrophilic silica surface with different alkyl chains (e.g., −C5H11, −C11H23 and −C17H35). This structural amendment maximizes the efficacy of silica nanopowder for the development of latent fingerprints. It was also observed that −C11H23 and −C17H35 containing amphiphilic silica nanopowders perform very efficiently for latent fingerprint development under visible light. To produce a luminescent silica nanopowder with similar surface character, a Pt(II)C^N^N−C12H25 luminophore with long hydrophobic aliphatic chain (−C12H25) was introduced to the silica surface. This electron-rich luminescent hybrid nanopowder can detect trinitrotoluene (TNT) through photoinduced electron transfer (PET) process. We successfully demonstrated that this Pt(II)-complex functionalized luminescent silica nanopowder could be useful for dual purpose; for the development of latent fingerprint along with simultaneous identification of explosive traces if present in the print.