Micro-structured fluorescent powders for detecting latent fingerprints on different types of surfaces

摘要

Benzazole dyes have shown great potential for application in different fields of science due to their intense and stable photoluminescence properties, associated with high sensitivity. In this study, we developed and evaluated micro-structured fluorescent powders based on benzazole dyes for fingerprint detection on different types (porous and non-porous) and colors (dark, white, and multi-colored) of surfaces. The new micro-structured powders were obtained by embedding a small amount of benzazole dye into a silica matrix (1:100 and 1:300 mass ratio) using an aqueous solution or ethanol under ambient conditions. The photophysical properties were characterized by UV-vis absorption and fluorescence emission spectroscopy. To assess the efficiency of these proposed powders, comparisons were performed with commercially available black, white, and fluorescent powders (Sirchie (R)) for different types of surfaces. The developed micro-structured powders showed intense fluorescence emission in the blue-green region, and a sharp contrast with the fingerprint residues when exposed to long wavelengths of UV light (365 nm) was observed, producing distinct ridge details on all examined surfaces.