Fluorescent Carbon Dots for Improved Visualization\nof Latent Fingermarks after Cyanoacrylate Fuming

The use of spectroscopic\nmethods to process fingermark evidence\nis a key procedure in forensic laboratories for identifying the perpetrator\nof a crime. However, latent fingermarks must first be developed. While\nmetal powders and dyes are commonly used as chemical developers, recent\nstudies have shown that nanomaterials may offer superior development\nperformance and numerous advantages. Herein, we corroborate this viewpoint\nreporting the successful utilization of carbon quantum dots (C-dots) as a fluorescent developer for\nlatent fingerprint deposited on aluminum substrates and previously\ntreated with cyanoacrylate fuming. These C-dots exhibit strong blue\nluminescence driven by emission from both core and surface emissive\nsites. Owing to the hydrogen bonds established between –OH,\n–COOH,\nand –NH groups from C-dots and –C N and –COOR\nin polymerized cyanoacrylate, C-dots adhere strongly to fingermark\nridges from various individuals, significantly enhancing contrast\nand details within pores and ridge morphology. The adsorbed C-dots\nare stable, and the photoluminescent mark remains visible even after\nwashing the developed fingermarks with water.