A mitochondria-targeted fluorescent probe for ratiometric detection of hypochlorite in living cells

Hypochlorous acid（HOCl） plays a vital role in many physiological and pathological processes as one of reactive oxygen species（ROS）. Developing highly sensitive and selective methods for HOCl detection is of significant interest. In this work, we developed a benzothiazole based probe 1 for ratiometric fluorescence detection of hypochlorite in living cells. The probe can detect HOCl with high selectivity, fast response（within 30 s） as well as low detection limit（0.18 mmol/L）. Fluorescence co-localization studies demonstrated that probe 1 was a mitochondria-targeted fluorescent probe. Furthermore, confocal fluorescence images of He La cell indicated that probe 1 could be used for monitoring intracellular HOCl in living cells. Finally, test strips experiment suggests that the probe 1 can detect the hypochlorous acid in tap water accompanied by remarkable color change.