A ratiometric fluorescence probe for rapid detection of mitochondrial SO2 derivatives

Abstract

In this study, we report a fluorescent probe (CBT) based on coumarin and benzothiazole moieties for detecting SO₂ derivatives (HSO₃⁻/SO₃²⁻) in a ratiometric fluorescence manner. Probe CBT exhibited desirable properties such as a high specificity, a rapid response, good water solubility and a low detection limit. The Michael addition reaction was proved to be the sensing mechanism of CBT. Moreover, fluorescence imaging of cells indicated that probe CBT with low cytotoxicity can be used to monitor the endogenous SO₂ derivatives in pathological liver cells (HepG2) but not in the normal liver cells (L-02), indicating that probe CBT can be applied to distinguish the two kinds of cells. Fluorescence co-localization studies proved that this probe shows an excellent mitochondria-targeting activity. Therefore, probe CBT has great potential to be applied in exploring the role of the SO₂ derivatives in biology.