A specific ratiometric-fluorescent probe for detection of hypochlorous based on oxidation-cyclization mechanism

The significance of hypochlorous acid in beverages, foodstuffs, as well as in pathological and physiological processes, has spurred substantial research efforts toward its real-time, in-field detection. In this work, phenothiazine and cyanoethylpyridine were joined through a vinyl bridge to construct a new ratiometric fluorescent probe, PVC. The probe features high specificity and sensitivity (LOD = 1.20 μM), alongside a rapid response time (≤110 s), a remarkably large Stokes shift (265 nm), and satisfactory photostability. Notably, the detection mechanism for HClO via a cascade process, oxidation sulfur formation sulfoxide, oxidation N, N-dimethylthiocarbamoyl group following intramolecular cyclization to formation of a pyran-imine. The probe PVC was successfully employed for HClO detection in both water and food matrices. Moreover, its ability to visualize endogenous and exogenous HClO in living cells and mice renders PVC a versatile platform for exploring a broad spectrum of HClO-associated physiological and pathological processes.