Two Aggregation-Induced Emission Actives Triphenylamine-Based Salicylaldimine Compounds for Latent Fingerprints Detection

To further explore the candidate materials for latent fingerprints detection, two triphenylamine-based salicylaldimine compounds containing phenoxazine moiety (TPA-PXZ) and carbazole unit (TPA-Cz) were designed and successfully synthesized, respectively. They exhibited intramolecular charge transfer transitions and aggregation-induced emission properties. Based on quantum chemical calculation results, it was found that compounds TPA-Cz and TPA-PXZ had twisted spatial configuration, which were responsible for aggregation-induced emission. Meanwhile, the morphology of two compounds nano-aggregates in the THF/water mixtures with 60 % and 80 % water content was tested. To our delight, the developers that prepared by compounds TPA-Cz and TPA-PXZ both were used for latent fingerprints detection on the surface of glasses, and they emitted purple fluorescence, as well as the distinct fingerprint imaging could be easily distinguished fingerprint level 1-3 details. We believe that TPA-Cz and TPA-PXZ both are the promising candidate for latent fingerprints detection. Two triphenylamine-based salicylaldimine compounds (TPA-PXZ and TPA-Cz) are designed and successfully synthesized. They possess excellent aggregation-induced emission performances due to their twisted spatial configuration. Importantly, two compounds as the developers could visualize latent fingerprints on the glass substrates, and could clearly detect three levels details of fingerprint features. image