NIR Mitochondrial Fluorescent Probe for Visualizing SO₂/Polarity in Drug Induced Inflammatory Mice

SO2 and polarity are important microenvironmental parameters in cells, which are closely related to physiological activities in organisms. The intracellular levels of SO2 and polarity are abnormal in inflammatory models. To this end, a novel near-infrared fluorescent probe BTHP that can simultaneously detect SO2 and polarity was studied. BTHP can sensitively detect polarity change with emission peak change from 677 to 818 nm. BTHP can also detect SO2 with fluorescence change from red to green. After addition of SO2, the fluorescence emission intensity ratio I517/I768 of the probe increased by about 33.6 times. BTHP can determine bisulfite in single crystal rock sugar with high recovery rate (99.2%–101.7%). Fluorescence imaging of cells showed that BTHP could better target mitochondria and monitor exogenous SO2 in A549 cells. More importantly, BTHP has been successfully used for dual channel monitoring SO2 and polarity in drug-induced inflammatory cells and mice. In particular, the probe showed increased green fluorescence with the generation of SO2 and increased red fluorescence with the decrease of polarity in inflammatory cells and mice.