A novel near-infrared fluorescent probe for visualization of intracellular hydrogen peroxide

Hydrogen peroxide (H₂O₂) as a crucial reactive oxygen species (ROS) plays a crucial role in redox signaling in physiological and pathological processes of living cells. Its normal production is closely related to signal transduction of living cells. Overproduction of H₂O₂ in vivo has been proved to be related to many diseases. Some were developed to reveal the roles of H₂O₂. However, current fluorescent probes for the detection of H₂O₂ are restricted in their short emission wavelengths and small Stokes shifts that significantly decrease the sensitivity of detection and cellular visualization. In this work, a novel fluorescent probe BC-B was designed and synthesized with pinacol phenylboronic acid ester as a recognition group and near-infrared fluorophore BC-OH as a reporter group. BC-B probe exhibits a large Stokes shift (122 nm) and near-infrared emission (672 nm), showing an excellent selectivity and sensitivity in detection of H₂O₂ with the limit of 0.003 μmol/L. Confocal fluorescence imaging further demonstrates that BC-B can be used for detecting endogenous H₂O₂ in living cells.