Water-soluble ratiometric fluorescent probes for exogenous and endogenous sulfur dioxide derivatives

Abnormal SO2 derivatives level induces mitochondrial and lysosomal dysfunction, which is associated with a variety of diseases. Therefore, it is imperative to develop fluorescent probes which are suitable for detection of SO2 derivatives in biological systems. Herein, we developed two new ratiometric fluorescent probes, MByn and HByn, which can respond to HSO3− in PBS buffer solution accurately and rapidly on basis of Michael addition reaction. After addition of HSO3−, ratiometric response signal increases by 5 folds, accompanied by a macroscopic change of fluorescence color. What's more, the two novel fluorescent probes MByn and HByn exhibited low detection limit (LOD = 0.96/0.79 μM), good photostability and low cytotoxicity. Cell imaging experiments showed that MByn and HByn were able to localize mitochondria and lysosomes accurately and detect both exogenous and endogenous SO2 derivatives in living cells.