Aggregation-induced fluorescence 'turn on' imaging for fingerprints by an amphiphilic probe: Synthesis and performance

Fingerprints are important biological details and play an important role in identifying personal information. To assist the identification of latent fingerprints (LFPs) which are the frequently-met cases in practical application, LFPs are usually made visible/detectable by development (imaging) techniques. In this work, an amphiphilic probe (denoted as HNP) was designed and synthesized. Its amphiphilic nature was confirmed by its single crystal structure and lipid-water partition coefficient (P = 1.38). It showed good solubility in water and bright red AIE (aggregation-induced emission) emission upon visible light excitation (similar to 410 nm), which satisfied the requirements for LFPs development/imaging. Photophysical parameters (absorption spectrum, emission spectrum, and emission quantum yield), LFPs imaging performance and bio-safety of probe HNP were discussed and re-ported. It was found that HNP showed efficient AIE effect in aggregated state. After meeting the lipids in LFPs, HNP AIE effect was activated, showing emission "turn-on " phenomenon and LFPs pattern. This mechanism was confirmed by micromorphology analysis. Corresponding dynamics were discussed as well. Good stability and durability were observed for HNP development/imaging. Details down to level 3 were successfully retrieved with high contrast.