A simple boronic acid-based fluorescent probe for selective detection of hydrogen peroxide in solutions and living cells.

An approach of high sensitivity and selectivity for hydrogen peroxide (HO) detection is highly demanded due to its important roles in regulating diverse biological process. In this work, we introduced an easily synthesized fluorescent "turn off" probe, BNBD. It is designed based on the core structure of 4-chloro-7-nitrobenzofurazan as a fluorophore and incorporated with a specific HO-reactive group, aryl boronate, for sensitive and selective detection of HO. We demonstrated its selectivity by incubating the probe with other types of ROS, and measured the limit of detection of BNBD as 1.8 nM. BNBD is also conducive to HO detection at physiological conditions. We thus applied it to detect both exogenous and endogenous changes of HO in living cells by confocal microscopy, supporting its future applications to selectively monitor HO levels and identify HO-related physiological or pathological responses from live cells or tissues in the near future.