Fluorescence spotting of latent sweat fingerprints with zinc oxide carbon dots embedded in a silica gel nanopowder: a green approach

Abstract

Constructing low-cost fluorescent-labelled materials is needed to meet the current demand in forensic security perceptions, such as identifying latent fingerprints (LFs). Colossal works of literature are spotted in LFs with...

Nanocomposites of nitrogen-doped carbon dots/hydrotalcite with enhanced solid-state fluorescence for the recognition of latent fingerprints

“…The clear feature structures of LFP image under 450 nm at level 2 and level 3 by the N-CD/hydrotalcite powder are distinguishable enough, which contains a large amount of important and useful information for individual identification and plays a vital role in the practical identification of LFPs. 33 The sufficiently strong fluorescence of N-CD/hydrotalcite with high contrast and quality without background interference on a glass substrate is also observed, illustrating that N-CD/hydrotalcite can overcome the reflection light from the glass substrate. For comparison, the bare N-CD nano-powder was used to detect LFPs on the glass substrate using the same method.…”

Hydrophobic‐Binding‐Driven and Fluoresence‐Free Development of Aged Fingerprints Based on Zinc Oxide Nanoparticles

“…Predictably, after being shaken adequately before being left stand, unmodified ZnO powder quickly settled to the bottom of the tube without any dispersion in solvent, suggesting a strong hydrophilicity ascribed to abundant hydroxyl groups on its surface. On the contrary, it can be seen [a] ZnO in Reference [49] is only an additive at a low amount, not the main component.…”

“…[44] Zinc oxide nanoparticle (ZnO NP) is famous for its cheaper cost, versatile utilization, and ease of surface processing for decades. [45][46] However, recent concerns about ZnO NPs in forensics were concentrating on the optical modification as fluorescent probes for fresh fingerprints, [47][48][49][50][51][52][53] and little attention was paid on their hydrophobization for aged fingerprint development. On the one hand, ZnO NP has large SSA and strong chemical activity, making it has more active sites with fingerprint residues theoretically.…”

A preparation strategy for multicolor carbon dots embedded in silicone for latent fingermarks and detection of AcO−

“…For example, most CDs exhibit the aggregation-caused quenching (ACQ) phenomenon. To overcome the ACQ effect, many researchers use starch, 17 silicon gel, [18][19][20][21] montmorillonite, 22 PVA, 23 organic silicon 24,25 and other materials to adsorb and disperse CDs. There is only physical adsorption between the CDs and the additives, and the binding is not firm.…”