Solid‐State Organic Fluorophore for Latent Fingerprint Detection and Anti‐Counterfeiting Applications

Abstract

A highly fluorescent material exhibiting solid‐state fluorescence is particularly important in detecting latent fingerprints (LFPs) and anti‐counterfeiting applications. Herein, we have synthesized a coumarin‐benzothiazole moiety 3‐(benzo[d]thiazol‐2‐yl)‐2H‐chromen‐2‐one (3‐BTC) to inspect its capability to visualize LFPs and work as an anti‐counterfeiting ink. The compound showed yellow‐greenish emission under UV excitation and good covertness under visible light conditions. With the help of the powder dusting method, the latent fingerprints were coated with 3‐BTC powder and images of the LFPs developed over various substrates including plastic, steel, aluminium plate, rubber, etc. under UV 365 nm light displayed good resolution be able to discern the patterns of all the levels 1–3. Apart from fresh fingerprints (taken within 10 seconds), aged (over 60 days) and incomplete eccrine LFPs were successfully visualized using 3‐BTC powder. Anti‐counterfeiting ink prepared using 3‐BTC also proved to be a promising candidate as an anti‐counterfeiting ink. Various types of paper materials, including tissue paper, printing paper, newspaper, etc. were used for evaluating 3‐BTC as a satisfactory anti‐counterfeiting ink.