Development of a mitochondrial-targeted ratiometric probe for the detection of SO2 in living cells and zebrafishes.

Sulfur dioxide (SO2), as the fourth gas signal molecule, is closely related to many diseases including respiratory diseases, nervous system diseases, cardiovascular diseases and cancers. Herein, we present a novel mitochondria-targeted ratiometric fluorescent probe (CS) for the detection of SO2 in living cells and zebrafishes. The probe CS was constructed on the base of coumarin and benzopyranium fluorophores, and exhibited intense blue and red fluorescence simultaneously. After the response to SO2, the fluorescence at 433 nm enhanced significantly while the fluorescence at 683 nm decreased obviously. The probe CS has a high sensitivity and selectivity to SO2. Moreover, the probe CS has been successfully applied to the detection of mitochondrial SO2 in living cells and zebrafishes.