Advanced synthesis and forensic application of CoPr(x)Cr(2-x)O4 nanoparticles for latent fingerprint detection

Abstract

The production, characterisation, and use of CoPr_(x)Cr_(2-x)O₄ (x = 0.00, 0.01, 0.03, and 0.05) nanoparticles for improved latent fingerprint (LFP) detection are investigated in this study. CoCr₂O₄ containing different amounts of Praseodymium(Pr³⁺) were prepared by solution combustion process using 1:1 M ratio of oxidizer and fuel. X-ray diffraction (XRD) was used to examine the structural characteristics of these nanoparticles, and the results showed that the crystallite sizes and lattice parameters varied while the spinel structure remained constant. The effective synthesis of the intended nanoparticles was indicated by the confirmation of CoCr₂O₄ presence in the spinel structure by Fourier Transform Infrared Spectroscopy, or FTIR. In particular, the study showed how these nanoparticles can be used in forensic science to identify LFP on a variety of surfaces, including steel, paper, and OHP sheets. In daylight, the CoPr_0.03Cr_1.97O₄ (CoPr-3)variation with x = 0.05 performed better, allowing for a clear viewing of Level I–III fingerprint features. 3D interactive plots and high-resolution images demonstrated that the nanoparticles stuck to fingerprint remnants, improving visibility and detail. The study also looked at how stable these nanoparticles were under UV irradiation and aging, and it discovered that CoPr-3 phosphor was remarkably resistant to UV degradation and retained its efficacy for 60 days. These results demonstrate the potential of CoPr_(x)Cr_(2-x)O₄ nanoparticles as a reliable and effective material for forensic fingerprint analysis, providing notable enhancements in LFP detection sensitivity and resolution.