Recent development of synthetic probes for detection of hypochlorous acid/hypochlorite

Hypochlorous acid/hypochlorite (HOCl/OCl^-), as one of the most important reactive oxygen species (ROS), plays an important role in various physiological and pathological processes. Nonproperly located or abnormal concentration of OCl^-, however, is associated with many diseases. Thus, developing the fluorescent probe for detecting OCl^- is of great significance. To this end, in last decade, many fluorescent probes have been developed and applied for detecting HOCl/OCl^- in vitro and in vivo. Despite a great progress has achieved, the development and application of near-infrared fluorescent HOCl/OCl^- probe still have some challenges. For example, highly specific and sensitive NIR fluorescent HOCl/OCl^- probes applied in endogenous OCl^- detection and subcellular organelle bioimaging. In this review, we summarized the representative cases of HOCl/OCl^- probes with properties that mentioned above. The discussion contains design strategies, detection mechanisms, as well as applications in bioimaging.