Sustainable Fluorescent Carbon Dots From Apple Snail Eggs for Enhanced Visualization of Shed Skin Cells in Latent Fingerprints

ABSTRACT Latent fingerprints contain shed skin cells that serve as critical DNA sources for forensic analysis; however, the efficiency of touch DNA analysis is often limited by insufficient cell quantities. This study presents a novel fluorescent carbon dot (CD) synthesized from a sustainable biomass source—apple snail eggs (ASE)—to enhance cell visualization in latent fingerprints. The ASE‐derived CDs (ASE‐CDs) were synthesized via a microwave‐assisted hydrothermal method, optimized with 0.1‐g/mL ASE extract at 1200 W, 200°C, for 60 min. The resulting ASE‐CDs exhibited strong fluorescence, with excitation and emission peaks at 351 and 416 nm, respectively. Transmission electron microscopy (TEM) revealed a uniform morphology with an average particle size of 5.4 nm, while X‐ray diffraction (XRD) and Fourier transform infrared (FT‐IR) spectroscopy confirmed their crystallinity, graphitization, and surface functional groups. ASE‐CDs enabled the effective visualization of shed skin cells in latent fingerprints, displaying higher fluorescence intensity than commonly used dyes—Diamond Nucleic Acid Dye (DD) and SYBR Green I Nucleic Acid Gel Stain (SGI)—while demonstrating lower photobleaching than DD. These findings highlight ASE‐CDs as a sustainable, eco‐friendly fluorescent probe with potential forensic applications.