Real Time Fluorescence in Situ Visualization of Latent Fingerprints Exceeding Level 3 Details Based on Aggregation Induced Emission.
A water soluble probe TPA 1OH with aggregation induced emission (AIE) activity is synthesized and used for expedient real time fluorescence in situ visualization of latent fingerprints (LFPs) TPA 1OH aqueous solution exhibits non fluorescence in pure water while strong fluorescence upon molecular aggregating induced by addition of non solvent. Fluorescence images of LFPs on variety of substrates, including rough surfaces such as walls, bricks, paper, are developed under 405 nm light, by im mersing in or spraying with TPA 1OH aqueous solution (30 mM) without any necessity of organic co solvent and post treatment steps. The probe is non cytotoxic at the concentration lower than 50 mM. The development process of LFPs is demonstrated by real time fluorescence in situ imaging. The exponential relationship between the relative fluorescence intensity and time is deduced from the fitting curve. The LFP images developed by TPA 1OH are evident and intact enough to allow that the Level 1 3 details are displayed and analyzed. Noteworthily, the Level 3 details of LFPs such as the fingerprint ridge width, the characteristics of the sweat pores are evidently visible under fluorescence microscopy. Even the nanoscopic details exceed ing Level 3 are visualized under super resolution microscopy with sub 50 nm optical resolution, which is the very first report on LFPs.
Journal of the American Chemical Society