Effect of Hydrophilic Quantum Dots Nano-Powder in Development of Latent Fingerprints on Various Surfaces

Abstract

In this research, hydrophilic quantum dot nano-powder (GQD@SiO2) was applied to compare the development of latent fingerprint on various surfaces and the development of latent fingerprint over time after fingerprint deposited. Hydrophilic quantum dot nano-powder exhibited green fluorescence under a wavelength of 365 nm ultraviolet, and increased adsorption characteristics through interaction with hydrophilic components in latent fingerprints showed clear minutiae on non-porous and semi-porous surfaces. It was difficult to express fingerprints on porous surfaces where fingerprint components were quickly absorbed, but on non-porous and semi-porous surfaces where fingerprint components could remain on the surface for a long time compared to porous surfaces, latent fingerprints could be expressed over time.