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 (H 2 O 2 ), which plays diverse roles in oxidative stress and redox signaling, are urgently needed to investigate the physiological and pathological effects of H 2 O 2 . A lack of reliable tools for in vivo imaging has hampered the development of H 2 O 2 mediated therapeutics. By combining a specific tandem Payne/Dakin reaction with a chemiluminescent scaffold, H 2 O 2 ‐CL‐510 was developed as a highly selective and sensitive probe for detection of H 2 O 2 both in vitro and in vivo. A rapid 430‐fold enhancement of chemiluminescence was triggered directly by H 2 O 2 without any laser excitation. Arsenic trioxide induced oxidative damage in leukemia was successfully detected. In particular, cerebral ischemia‐reperfusion injury‐induced H 2 O 2 fluxes were visualized in rat brains using H 2 O 2 ‐CL‐510 , providing a new chemical tool for real‐time monitoring of H 2 O 2 dynamics in living animals.