Magnetic perovskite nanoparticles for latent fingerprint detection

Abstract

Fingerprints form when fingers touch a solid surfaceand are considered the best way for individual identification. However, the current latent fingerprint (LFP) developing methods cannot meet the demand for high sensitivity and being convenient and healthy. Herein, bifunctional Fe₃O₄@SiO₂–CsPbBr₃ powders have been designed and fabricated and exhibit good magnetic and strong fluorescent properties. The magnetism of Fe₃O₄ can avoid dust flying, while the fluorescence of CsPbBr₃ ensures the high definition of LFPs. Clear fingerprints have been detected on various solid substrates using the Fe₃O₄@SiO₂–CsPbBr₃ powders instead of eikonogen. Detailed characterization studies suggest that the ammonium cationic groups on the surface of nanoparticles (NPs) have strong adhesive interactions with the residues of fingerprints because of the electrostatic attraction between them. Therefore, the convenient operation and excellent resolution offer great opportunity in the practical application of fingerprint detection and other areas.