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, H-1 and C-13 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 Cu2+ 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 mu M. Meanwhile, driving by the metal binding ability of the pincer-like structure of hydroxyl and imidazole group, HTPEAIM was used for sensing Cu2+ 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.

Automated summary

A novel tetraphenylethylene (TPE)-functionalized arylimidazole derivative (HTPEAIM) was successfully designed and synthesized, showing excellent aggregation-induced emission (AIE) properties and sensitivity in detecting picric acid (PA) and Cu2+ in aqueous solutions. The study also revealed the underlying mechanisms for the detection processes, achieving low limits of detection for both analytes.