The exquisite integration of ESIPT, PET and AIE for constructing fluorescent probe for Hg(II) detection and poisoning

Excessive mercury ions (Hg2+) in the environment can accumulate in human body along with the food chain to cause serious physiological reactions. The fluorescence probes were considered as convenient tool with great potential for Hg2+ detection. Most existing probes suffer from aggregation-induced quenching (ACQ) effects and insufficient sensitivity. Herein, a novel type of fluorophore was developed by combining the aggregation-induced emission (AIE) and excited state intramolecular proton transfer (ESIPT) characteristics. Subsequently, a phenyl thioformate group with photoinduced electron transfer (PET) effect was connected to give an efficient "turn-on" probe (HTM), which exhibited good selectivity toward Hg2+, short response time (30 min), coupled with extremely low detection limit (LOD = 1.68 nmol/L). In addition, HTM was used successfully in real samples, cells and drug evaluation, underlying the superiority of HTM to detect Hg2+ in practical applications.