A selective fluorescent turn-on probe for imaging and sensing of hydrogen peroxide in living cells

Fluorescent turn-on probes have been extensively used in disease diagnosis and research on pathological disease mechanisms because of their low background interference. Hydrogen peroxide (H₂O₂) plays a vital role in regulating various cellular functions. In the current study, a fluorescent probe, HCyB, based on hemicyanine and arylboronate structures, was designed to detect H₂O₂. HCyB reacted with H₂O₂ and exhibited a good linear relationship for H₂O₂ concentrations ranging from 15 to 50 μM and good selectivity over other species. The fluorescent detection limit was 76 nM. Moreover, HCyB exhibited less toxicity and mitochondrial-targeting abilities. HCyB was successfully used to monitor exogenous or endogenous H₂O₂ in mouse macrophage RAW 264.7, human skin fibroblast WS1, breast cancer cell MDA-MB-231, and human leukemia monocytic THP1 cells.