Tandem Payne/Dakin Reaction: A New Strategy for Hydrogen Peroxide Detection and Molecular Imaging

Hydrogen peroxide (H 2 O 2 ) has been recognized as one of the most significant ROS (reactive oxygen species) in human health and disease. Because of the intrinsic attributes of H 2 O 2 —such as its low reactivity under physiological pH—it is exceedingly challenging to develop small‐molecule fluorescent probes with high selectivity and sensitivity for visualization of H 2 O 2 in an intricate biological milieu. To address this gap, a rationally designed tandem Payne/Dakin reaction is reported that is specific to molecular recognition of H 2 O 2 . New H 2 O 2 probes based on this unique chemical strategy can be easily synthesized by a general coupling reaction, and the practical applicability of those probes has been confirmed by the visualization of endogenously produced H 2 O 2 in living cells. In particular, starvation‐induced H 2 O 2 production in mouse macrophages has been detected by the novel probe in both confocal imaging and flow cytometry. This tandem Payne/Dakin reaction provides a basis for developing more sophisticated molecular tools to interrogate H 2 O 2 functions in biological phenomena.