Color-Tunable Binuclear (Eu, Tb) Nanocomposite Powder for the Enhanced Development of Latent Fingerprints Based on Electrostatic Interactions

Abstract

Fluorescence color of rare earth-based nanopowder can be modulated by regulating the molar ratio of components, which offers a promising strategy in many fields of applications. Herein, a series of binuclear Eu Tb(AA)Phen ( x = 1, 0.75, 0.5, 0.25, 0.1, 0) complexes were fabricated using acrylic acid (AA) as the first ligand and using 1,10-phenanthroline (Phen) as the second ligand. The characterization results showed that this novel binuclear (Eu, Tb) complex can emit strong red or green light via simply varying the molar ratio of europium and terbium. Moreover, the results of spectroscopic and zeta potential analyses suggested that there was an electrostatic adherence mode in the interaction between the Eu Tb(AA)Phen complex and fingerprint residues. Importantly, our Eu Tb(AA)Phen nanopowder was successfully applied to the enhanced development of latent fingerprints on various surfaces by the powder dusting method, exhibiting a high contrast, sensitivity, and selectivity, as well as a low detection limit in forensic science, which was further confirmed by analysis with an automatic fingerprint identification system. In summary, our synthetic rare earth-based nanopowder exhibits promise as an ideal fluorescent probe for the enhanced development of latent fingerprints, based not only on physical absorption at the macrolevel but also on electrostatic interactions between our rare earth complex and fingerprint residues at the molecular level, which could provide an enhanced affinity compared with traditional fingerprint powders.

Novel organic–inorganic hybrid powder SrGa12O19:Mn2+–ethyl cellulose for efficient latent fingerprint recognitionviatime-gated fluorescence

“…Aer adding the LFPs by nger touching the surface of the KBr pellet, some peaks appeared due to the organic matter at 2923 cm À1 and 1740 cm À1 . 22 In pure EC, the water peak shied from 3472 cm À1 to 3465 cm À1 in Fig. S4.…”

“…6), where the peak at 3469 cm À1 shied to 3465 cm À1 , indicating the presence of hydrophobic interactions. 22 Such chemical adsorption is stronger than physical adsorption, which increased the strength of connections between the powder and the ngerprint, thereby increasing the resolution of the resolved ngerprints. The main peaks of EC are listed in Table 2.…”

“…Additionally, the emission color varies depending on the substance that is used, leading to a complex imaging process, and this method is unable to completely eliminate background uorescence. 22 Physically adsorbed materials have a weak affinity for ridges. 23 Some probes can only resolve rstand second-level ngerprint features of the ngerprint degree but not the third-level features.…”

“…14,34 The resolution and contrast of imaging can be enhanced by using organic matter such as coumarin A with functional groups that generate electrostatic interactions to adhere the LFPs on the surface of the uorescent powder. 4,5,8,22 Herein, we successfully designed and synthesized a LFP probe by using a simple organic-inorganic hybrid strategy to combine the inorganic aerglow phosphor SrGa 12 O 19 :Mn 2+ (SGO:Mn) and ethyl cellulose (EC). SGO is a superior aerglow host lattice, as reported in our previous works, and the proper crystal eld environment for Mn 2+ ions' narrow band emitting can be provided by the SGO host.…”

Diazonium Gold Salts as Novel Surface Modifiers: What Have We Learned So Far?

“…Biological samples taken from crime scenes as evidence, such as fingerprints, elucidate more facts about the possible suspects and crime itself in the forensic investigations [27]. Latent fingerprints detection was developed rapidly include powdering [27,28], fluorescent imaging [29], visualization using polyelectrolytes [30], and cyanoacrylate fuming [31], scanning Kelvin probe [32], metal vapor deposition [33], and redox approaches for metal surfaces [34].…”