NIR-induced highly sensitive detection of latent fingermarks by NaYF4:Yb,Er upconversion nanoparticles in a dry powder state

Abstract

The most commonly found fingermarks at crime scenes are latent and, thus, an efficient method for detecting latent fingermarks is very important. However, traditional developing techniques have drawbacks such as low detection sensitivity, high background interference, complicated operation, and high toxicity. To tackle this challenge, we employed fluorescent NaYF4:Yb,Er upconversion nanoparticles (UCNPs), which can fluoresce visible light when excited by 980 nm human-safe near-infrared light, to stain the latent fingermarks on various substrate surfaces. The UCNPs were successfully used as a novel fluorescent label for the detection of latent fingermarks with high sensitivity, low background, high efficiency, and low toxicity on various substrates including non-infiltrating materials (glass, marble, aluminum alloy sheets, stainless steel sheets, aluminum foils, and plastic cards), semi-infiltrating materials (floor leathers, ceramic tiles, wood floor, and painted wood), and infiltrating materials such as various types of papers. This work shows that UCNPs are a versatile fluorescent label for the facile detection of fingermarks on virtually any material, enabling their practical applications in forensic sciences.

EDTA-assisted phase conversion synthesis of (Gd0.95RE0.05)PO4 nanowires (RE = Eu, Tb) and investigation of photoluminescence

“…Rare-earth (RE) ions present numerous well-defined electronic transitions involving their 4f and 5d shells, and the RE-related materials have been applied in solid-state lasers, plasma display panels (PDPs), biolabeling, and so on [6–8]. Wang et al [9] employed NaYF 4 :Yb,Er up-conversion nanoparticles as a novel fluorescent label for the detection of latent fingermarks with high sensitivity and broad applicability. As for 1D nanomaterials, Yang et al [10] prepared nearly monodispersed and well-defined Gd 2 O 3 :Eu 3+ nanorods and microrods through hydrothermal reaction followed by conventional annealing, and explored their size-dependent photoluminescence for potential application in high-performance phosphors.…”

Neodymium doped yttrium aluminate synthesis and optical properties – A blue light emitting nanophosphor and its use in advanced forensic analysis

“…Latent FP residue composed primarily of lipids such as squalene, fatty acids, and cholesterol adheres to a large number of substances. The NPs must adhere to the FPs and not to the surface nearby the FPs is the requirement [36,37].…”

Down-shifting luminescence of water soluble NaYF4:Eu3+@Ag core-shell nanocrystals for fluorescence turn-on detection of glucose

“…Among these materials, fluorides doped with RE ions have low photon energies and high quantum efficiencies, giving them potential for widespread applications in optical communication, display devices, and solid-state lasers. Especially, NaYF4 is acknowledged as the most efficient host material at present [16].…”