A novel tetraphenylethylene-functionalized arylimidazole AIEgen for detections of picric acid and Cu2

A novel tetraphenylethylene (TPE)-functionalized arylimidazole derivative ( HTPEAIM ) has been designed and synthesized. The structure was characterized by FT-IR, HR-MS, 1 H and 13 C NMR. The photophysical properties were investigated by UV–vis absorption and PL spectra. HTPEAIM exhibited excellent aggregation-induced emission (AIE) property that it was non-emission in organic solution and with high fluorescence in aggregation state as the restriction of intramolecular motions (RIMs). Moreover, HTPEAIM could be a fluorogenic probe for sensing picric acid (PA) and Cu 2+ in the aqueous environment. Since the proton binding capacity of the N atom of the imidazole group and the donor–acceptor interactions, HTPEAIM was able to sensitively and selectively detect PA through the synergistic effects of photoinduced energy transfer (PET) and fluorescence resonance energy transfer (FRET) with a limit of detection (LOD) of 0.99 μM. Meanwhile, driving by the metal binding ability of the pincer-like structure of hydroxyl and imidazole group, HTPEAIM was used for sensing Cu 2+ in the aqueous environment. The response mechanism was systemically studied, and the results showed that the stable Cu( HTPEAIM ) 2 complex was formed and that induced the fluorescence highly quenching to obtain a low LOD of 34.8 nM. Graphical Abstract