[en] In this study, amphiphilic polymers such as poly(vinyl pyrrolidione) (PVP) were directly adsorbed onto the surface of semiconductor QDs to overcome the limitations described. The detection ability on latent fingerprints is expected to improve if nanomaterials are used, because they exhibit good emission and have functionalities that can interact with fingerprint residues, thereby leading to better sensitivity and selectivity in latent fingerprint detection. The limitations on the detection of latent fingerprint found in crime scenes can be overcome by the excellent emission of nanoparticles. Moreover, the detection sensitivity can be improved by in troducing new nanomaterials that can interact with the surface of fingerprint residues.

[en] Highlights: • Lead halide perovskite nanocrystals were synthesized via hot injection. • Perovskite nanocrystals remain highly optically stable after purification. • Perovskite nanocrystals afford sensitive and specific latent fingerprint detection. Latent fingerprints (LFPs) are one of the most important forms of evidence in crime scenes due to the uniqueness and permanence of the friction ridges in fingerprints. Therefore, an efficient method to detect LFPs is crucial in forensic science. However, there remain several challenges with traditional detection strategies including low sensitivity, low contrast, high background, and complicated processing steps. In order to overcome these drawbacks, we present an approach for developing latent fingerprints using stabilized CsPbBr₃ perovskite nanocrystals (NCs) as solid-state nanopowders. We demonstrate the superior optical stability of CsPbBr₃ NCs with respect to absorption, photoluminescence (PL), and fluorescence lifetime. We then used these highly stable, fluorescent CsPbBr₃ NCs as a powder dusting material to develop LFPs on diverse surfaces. The stable optical properties and hydrophobic surface of the CsPbBr₃ NC nanopowder permitted high resolution images from which unique features of friction ridge arrangements with first, second, and third-level LFP details can be obtained within minutes.