A Highly Selective and Sensitive Chemiluminescent Probe for Real-Time Monitoring of Hydrogen Peroxide in Cells and Animals.

Selective and sensitive molecular probes for hydrogen peroxide (H2 O2 ), which plays diverse roles in oxidative stress and redox signaling, are urgently needed to investigate the physiological and pathological effects of H2 O2 . A lack of reliable tools for in vivo imaging has hampered the development of H2 O2 mediated therapeutics. By combining a specific tandem Payne/Dakin reaction with a chemiluminescent scaffold, H2 O2 -CL-510 was developed as a highly selective and sensitive probe for detection of H2 O2 both in vitro and in vivo. A rapid 430-fold enhancement of chemiluminescence was triggered directly by H2 O2 without any laser excitation. Arsenic trioxide induced oxidative damage in leukemia was successfully detected. In particular, cerebral ischemia-reperfusion injury-induced H2 O2 fluxes were visualized in rat brains using H2 O2 -CL-510, providing a new chemical tool for real-time monitoring of H2 O2 dynamics in living animals.

Fluorescent Probe HKSOX-1 for Imaging and Detection of Endogenous Superoxide in Live Cells and In Vivo.

Superoxide anion radical (O2(•-)) is undoubtedly the most important primary reactive oxygen species (ROS) found in cells, whose formation and fate are intertwined with diverse physiological and pathological processes. Here we report a highly sensitive and selective O2(•-) detecting strategy involving O2(•-) cleavage of an aryl trifluoromethanesulfonate group to yield a free phenol. We have synthesized three new O2(•-) fluorescent probes (HKSOX-1, HKSOX-1r for cellular retention, and HKSOX-1m for mitochondria-targeting) which exhibit excellent selectivity and sensitivity toward O2(•-) over a broad range of pH, strong oxidants, and abundant reductants found in cells. In confocal imaging, flow cytometry, and 96-well microplate assay, HKSOX-1r has been robustly applied to detect O2(•-) in multiple cellular models, such as inflammation and mitochondrial stress. Additionally, our probes can be efficiently applied to visualize O2(•-) in intact live zebrafish embryos. These probes open up exciting opportunities for unmasking the roles of O2(•-) in health and disease.

HKOCl-3: a fluorescent hypochlorous acid probe for live-cell and in vivo imaging and quantitative application in flow cytometry and a 96-well microplate assay.

Ultra-selective and ultra-sensitive probes for hypochlorous acid (HOCl), one of the most poorly understood reactive oxygen species (ROS), are urgently needed to unravel the HOCl functions in important biological processes such as development and innate immunity. Based on a selective oxidative O-dearylation reaction of 2,6-dichlorophenol toward HOCl over other reactive oxygen species, we have developed a novel fluorescent probe HKOCl-3 for HOCl detection with ultra-selectivity, ultra-sensitivity and a rapid turn-on response. The functional robustness of HKOCl-3 for endogenous HOCl detection and imaging has been thoroughly scrutinized in multiple types of phagocytes and in vivo imaging of live intact zebrafish embryos. Furthermore, HKOCl-3 has been successfully applied to the detection of endogenous HOCl by a 96-well microplate assay and flow cytometry. Therefore, HKOCl-3 holds great promise as a versatile molecular tool that enables innovative investigation of HOCl biology and ROS-related diseases in multiple detection modalities.