A red-emission iridium ( III ) complex-based fluorescent probe with Schiff base structure for selection detection HOCl and its application in water sample

Hypochlorous acid (HOCl), a kind of reactive oxygen species (ROS), has been reported to be related to many human diseases, such as Parkinson's diseases, arthritis and cancers. Herein, a red-emission Ir(III) complex-based probe 1 for quantitative detection of HOCl was prepared and characterized by H-1 and C-13 NMR, IR and HRMS. For probe 1 , benzenesulfonylhydrazine group was introduced to the main N <^> C lig-ands phenylpyridine to quench fluorescence due to the isomerization of C = N bond. After reaction with HOCl in 30% DMF/PBS solution, the benzenesulfonylhydrazine group was taken off and fluorescent com-plex Ir-CHO was generated. The fluorescence intensity at 625 nm was significantly enhanced, and finally increased by 23 times. The experiment results demonstrated that probe 1 possessed large Stokes shift (ca. 195 nm), low detection limit (1.3728 x 10(-6) M), fast response (25 s), and high selectivity toward HOCl without interference from other ions and bio-related species. In addition, probe 1 exhibited good stability and water solubility. Moreover, it could be further applied in actual water for quantitative detection of HOCl with high recovery rate (95% - 101%). (C) 2022 Published by Elsevier B.V.