Sensitive Fingerprint Detection Using Biocompatible Mesoporous Silica Nanoparticle Coating on Non-Porous Surfaces

In recent years, the development and application of biocompatible nanomaterials in the detection of fingerprints have become a major focus for the forensic sector and crime investigators. This study aims to synthesize biocompatible silica nanoparticles (Si NPs) through cost-effective green methods and will be used to detect a latent fingerprint on a non-porous surface. As a type of environmentally friendly nanomaterial, Si NPs were prepared via an oil–water mixed micro-emulsion templating (MET) approach. Their characteristics and optical properties were measured using EDX-SEM, HR-TEM, FTIR, XRD, and UV–visible absorption. The biocompatibility of the synthesized Si NPs in terms of cell viability was observed, even at high concentrations (83.46% and 75.28% at 20 and 50 mg mL⁻¹, respectively). The developed Si NPs were tested on different surfaces, including plastic, glass, silicon, steel, and soft plastic for the detection of crime scene fingerprints. In this research, it was found that the Si NPs were of the size of 100–150 nm. Results confirmed that synthesized mesoporous Si NPs can be used to detect latent fingerprints on multiple non-porous surfaces and were easy to detect under a UV lamp at 395 nm. These findings reinforce the suggestion that the developed Si NP coating has a high potential to increase sensitive and stable crime traces for forensic latent fingerprint detection, even in packaged food with different packaging surfaces.