A fluorescein-based “turn-on” fluorescence probe for hypochlorous acid detection and its application in cell imaging

A simple fluorescent probe F-BH was designed and synthesized, introducing CN group which can be a recognition site for hypochlorous acid into the fluorescent probe molecule by using 2-benzothiazole hydrazone and formylated fluorescein. The fluorescence intensity of the probe F-BH solution was very weak, while the fluorescence of the solution was obviously enhanced and the color of the solution changed after the addition of ClO− ion. The selection and competition experiments proved that the probe has great selectivity for recognition of hypochlorous acid over other ROSs/RNSs and anions. Fluorescence titration experiments show that the probe has a low detection limit (17.5 nM). The probe has been successfully applied to real-time detection of hypochlorous acid in Hela cells.