Synthesis of gold nanoparticles immobilized on fibrous nano‐silica for latent fingerprints detection

Fingerprint, as the main basis of individual identification, plays a vital role in various areas, including criminal investigation and forensic detection. Accordingly, it is highly significant to develop methods for fingerprint detection with high sensitivity and accuracy. In this study, Au@KCC-1 nanocomposites with easy accessibility of active sites were prepared by a convenient method, and the feasibility of obtained Au@KCC-1 nanocomposites were finally investigated on latent fingerprints detection. Due to the immobilization effect of the KCC-1 carrier on Au NPs, the formed Au@KCC-1 nanocomposites showed stable chemical structures, excellent selectivity, and high sensitivity. Using Au@KCC-1 nanocomposites as a new type of fingerprint powders, latent fingerprints could be enhanced with clear patterns, satisfactory ridge details, and even sweat pores, and it was successfully employed to enhance latent fingerprints deposited on various object surfaces (such as blue plastic, black paper, foundation box, red cardboard, glass, and plastic Blue-ray CD discs (the smooth side)) for individual identification. The results demonstrated that Au@KCC-1 nanocomposites powders could be an alternative to commercially available fingerprint powdering reagents in forensic detection in the future.