A mitochondria-targeted ratiometric fluorescent probe for hypochlorite and its applications in bioimaging.

A novel ratiometric probe (RCP) for -OCl was developed based on the fluorescence resonance energy transfer (FRET) platform. The probe was constructed by integrating the coumarin moiety (FRET donor) with the rhodamine moiety (FRET acceptor). Upon treatment with -OCl, the coumarin emission at 483 nm decreased and the rhodamine emission at 570 nm increased, enabling the probe to provide accurate detection of -OCl (in the concentration range of 0-50 μM). The probe exhibited brilliant selectivity and sensitivity, rapid response and low cytotoxicity. More importantly, the introduction of the quaternized pyridine moiety can not only manage to increase the solubility, but also achieve mitochondria-targeting. The probe was applied successfully to imaging endogenous -OCl in mitochondria, highlighting its potential applications in bioanalysis.