A 3,7-Dihydroxyphenoxazine-based Fluorescent Probe for Selective Detection of Intracellular Hydrogen Peroxide

A novel N-borylbenzyloxycarbonyl-3,7-dihydroxyphenoxazine fluorescent probe (NBCD) for detecting H2O2 in living cells is described. The probe could achieve high selectivity for detecting H2O2 over other biological reactive oxygen species (ROS). In addition, upon addition of H2O2, NBCD exhibited color change from colorless to pink, which makes it a "naked-eye" probe for H2O2 detection. NBCD could not only be used to detect enzymatically generated H2O2 but also to detect H2O2 in living systems by using fluorescence spectroscopy, with a detection limit of 2 μm. Importantly, NBCD enabled the visualization of epidermal growth factor (EGF)-stimulated H2O2 generation inside the cells.