Fluorescent Carbon Dots for Improved Visualization of Latent Fingermarks after Cyanoacrylate Fuming

The use of spectroscopic methods to process fingermark evidence is a key procedure in forensic laboratories for identifying the perpetrator of a crime. However, latent fingermarks must first be developed. While metal powders and dyes are commonly used as chemical developers, recent studies have shown that nanomaterials may offer superior development performance and numerous advantages. Herein, we corroborate this viewpoint reporting the successful utilization of carbon quantum dots (C-dots) as a fluorescent developer for latent fingerprint deposited on aluminum substrates and previously treated with cyanoacrylate fuming. These C-dots exhibit strong blue luminescence driven by emission from both core and surface emissive sites. Owing to the hydrogen bonds established between –OH, –COOH, and –NH groups from C-dots and –C≡ N and –COOR in polymerized cyanoacrylate, C-dots adhere strongly to fingermark ridges from various individuals, significantly enhancing contrast and details within pores and ridge morphology. The adsorbed C-dots are stable, and the photoluminescent mark remains visible even after washing the developed fingermarks with water.