Efficient in situ growth of platinum nanoclusters on the surface of Fe3O4 for the detection of latent fingermarks

Abstract

Hydrophobic Fe3O4 nanoparticles were modified with polyethyleneimine (PEI) to obtain hydrophilic Fe3O4 nanoparticles. By reducing the content of H2PtCl6 solution by using l-ascorbic acid (AA) as a reductive agent, fluorescent platinum nanoclusters (Pt NCs) were incubated into the PEI-modified Fe3O4 nanoparticles. The prepared Fe3O4@Pt NCs microspheres possessed a uniform size, improved monodispersity, high magnetization (40.8 emu/g) and high fluorescence quantum yield (9.0%). Moreover, compared to the reported methods, this method demonstrated that the incubation of Pt NCs on the surface of PEI-Fe3O4 was more convenient and needed less reaction time (about 10 min). The experimental results showed that latent fingermarks developing with Fe3O4@Pt NCs powder exhibit excellent ridge details. The Fe3O4@Pt NCs with superparamagnetism and excellent fluorescence showed great potential in forensic science.