A "Turn-On" Fluorescent Probe with High Selectivity and Large Stokes Shift for the Detection of Hydrogen Peroxide and Its Bioimaging Applications

Hydrogen peroxide (H2O2) plays pivotal roles in various biological functions and pharmacological activities. High selectivity and sensitivity remain challenges for fluorescent probes to detection of H2O2 with a large stokes shift. Herein, a new "turn-on" fluorescent probe (DCM-C) was designed based on the mechanism of intramolecular charge transfer (ICT). In PBS buffer (10 mM, pH 7.4, with 20% DMSO, v/v), DCM-C exhibited high selectivity and sensitivity for H2O2 over other interfering analytes with a large stokes shift (187 nm), and the detection limit was as low as 35.5 nM. In addition, the probe was effective for detecting exogenous and endogenous H2O2 in living cells, and identifying stained in cytoplasm. Moreover, the probe has been used successfully for determining H2O2 in zebrafish by fluorescence imaging.