Optical Detection of Latent Fingerprints via SBA-15/PhCN Visible-Light-Active Material.

The development of novel materials and techniques for fingerprint detection remains a key challenge in forensic science, particularly for latent prints deposited on complex, multicolored, or low-contrast surfaces. Conventional detection methods often face limitations in sensitivity, selectivity, and environmental compatibility, prompting a search for innovative and sustainable alternatives. In this work, we report the synthesis and application of an SBA-15/PhCN hybrid system as an efficient and eco-friendly material for the visible-light detection of both fresh and latent fingerprints on various substrates. The combination of mesoporous silica SBA-15, characterized by its high surface area and tunable pore architecture, with the photoreactive organic compound phenyl-doped carbon nitride (PhCN) results in a hybrid exhibiting enhanced optical response and strong interaction with fingerprint residues under visible illumination. The hybrid material was synthesized through a facile and reproducible route, thoroughly characterized by spectroscopic and microscopic analyses, and applied via a conventional powder dusting method. Its performance was systematically evaluated on glass, metal, and plastic substrates, demonstrating a high contrast and excellent ridge definition. The SBA-15/PhCN hybrid exhibited strong visible-light activity and high selectivity toward fingerprint residues, confirming its potential as a sustainable, noninvasive, and cost-effective material for advanced forensic investigations.