Borinic Acids as New Fast-Responsive Triggers for Hydrogen Peroxide Detection.

Detection of hydrogen peroxide (H2O2), which is responsible for numerous damages when overproduced, is crucial for a better understanding of H2O2-mediated signalling in physiological and pathological processes. For this purpose, various“off-on” small fluorescent probes relying on a boronate trigger have been developed. However, they suffer from low kinetics and do not allow forH2O2-detectionwith a short response time. Therefore, more reactive sensors are still awaited. To address this issue, we have successfully developed the first generation of borinic-based fluorescent probes containing a coumarin-scaffold. We determined the in vitrokinetic constants of the probe toward H2O2-promotedoxidation. We measured 1.9x104m-1.s-1as a second order rate constant, which is 10 000 faster than its boronic counterpart (1.8 m-1.s-1). This remarkable reactivity was also effective in a cellular context, rendering the borinic trigger an advantageous new tool for H2O2detection.