Design, Synthesis and Performance of Fluorescent Probe for Detection of Hg2+ With 1,3-Oxathiolane as Receptor

Hg2+ is one of the most toxic heavy metal ions, which can cause air, soil, and water pollution, seriously damaging human health. Therefore, developing effective analytical methods to detect Hg2+ in environmental systems is particularly important. Fluorescent probes have been widely used to detect Hg2+ due to their advantages, such as high sensitivity, good selectivity, fast response time, and real-time online detection. In this paper, a novel turn-on fluorescent probe (2-(pyren-1-yl)-1,3-oxathiolane, POX) with 1,3-oxathiolane as receptor was designed and synthesized based on Hg2+-promoted deprotection reaction of thioacetal, and H-1 NMR, C-13 NMR, and HRMS characterized its structure. The selectivity, competitiveness, concentration titration, pH titration, time dependence, the limit of detection, and recognition mechanism of POX for the detection of Hg2+ in CH3CH2OH/H2O solution were investigated. The results showed that POX could quickly recognize Hg2+ in a wide pH range and exhibited high selectivity and sensitivity. Adding Hg2+ to the solution of POX resulted in a clear fluorescence emission peak at 386 nm, indicating that POX showed a remarkable turn-on fluorescence for Hg2+, and its recognition process was almost unaffected by other metal ions. Fluorescence titration experiments indicated that POX had a good linear response (R-2=0.999 4) in the range of Hg2+ from 0 similar to 6.5 mu mol.L-1, with a detection limit of 0.168 mu mol.L-1. The RSD of POX for detecting Hg2+ in actual water samples was less than 2.92%. The simple synthesis, easy availability of raw materials, and wide pH applicability of POX suggested that it could be used as a potential tool for the qualitative and quantitative detection of Hg2+ in the environment.