Cross-Linking Induced Emission of Polymer Micelles for High-Contrast Visualization Level 3 Details of Latent Fingerprints

Abstract

Rationally developing an intelligent tool for highcontrast fluorescence imaging of latent fingerprints (LFPs) is gaining much concern in many applications such as medical diagnostics and forensic investigations. Herein, the off−on fluorescent polymer micelles (PMs) have been rationally designed and synthesized for high-contrast fluorescence imaging of LFPs through the cross-linking reaction of hydrazine (N 2 H 4 ) and aldehyde group of polymer. Excitingly, the cross-linking (N 2 H 4 ) induced emission of PMs has the property of aggregation-induced emission (AIE) and excited state intramolecular proton transfer (ESIPT), which could effectively address the notorious aggregation-caused quenching (ACQ) effects of conventional organic dyes. In addition, the cross-linking strategy can not only improve structural stability of PMs but also enhance its fluorescence brightness. The experiment results demonstrated that PMs showed high water dispersibility (100% aqueous solution), high selectivity, large Stokes shift (∼150 nm), good photostability, and excellent long-term stability. Because of the hydrophobic interaction between the PMs and fingerprint components, the PMs preferentially adhered onto the ridges of fingerprint, and then cross-linking (N 2 H 4 ) induced emission properties endowed the PMs for high-contrast imaging of LFPs in different substrates, especially the levels 1−3 details of LFPs. We expect that this strategy will provide vital support for LFPs technology.

Starch-based near-infrared organic fluorophores for the imaging of latent fingerprints

“…Owing to the bright NIR solid-state emission of BrBTN and high absorptive capacity of porous starch, the obtained NIR emissive fingerprint powder provided good fluorescent images of fingerprints with high contrast and resolution with a gray ratio as high as 14. These results are 3-times higher than that of the commercial red fingerprint powder and also higher than that of other reported fluorescent powders used in fingerprint development, [30][31][32] as shown in Fig. S8 (ESI †).…”

Dual-Responsive Benzo-Hemicyanine-Based Fluorescent Probe for Detection of Cyanide and Hydrogen Sulfide: Real-Time Application in Identification of Food Spoilage

“…Several dual- or multi-responsive longer wavelength fluorescence probes have recently been reported to detect these anions using hemicyanine derivatives, owing to the lower cost, ease of synthesis, good biocompatibility, and adequate water solubility. However, the limitations of these organic probes include low wavelength emission, poor solvent medium, higher detection limit, and restricted applications. − In this paper, we present a red-emitting fluorescent probe based on benzo-hemicyanine that can detect CN – and HS – ions via two separate reaction sites. The nucleophilic addition of the CN – and HS – ions (CN + /CC) to their respective reaction sites would alter the system’s conjugation.…”

A fluorescent molecular rotor for the in situ imaging of latent fingerprints

“…5 To overcome these limitations, fluorescent small molecules and polymeric particles with minimal processing steps have been developed. 6,7 More recently, fluorophores with aggregation-induced emission (AIE) have been reported to offer potential improvement over conventional reagents 8,9 because AIE-based reagents display strong fluorescence enhancement upon adhering to fingerprints (‘turn-on’ response) and exhibit great sensitivity, allowing the detection of level 2–3 details. As described in Fig.…”