A Fluorescent Probe for Ratiometric Imaging of SO2 Derivatives in Mitochondria of Living Cells

When SO2 is inhaled through the respiratory tract into the body, it can be easily hydrated to sulfite (SO32-) and bisulfate (HSO3-) ions. They are widely used as essential preservatives for foods, beverages, and pharmaceutical products. Exposure to high doses of bisulfate induces a large number of respiratory diseases relevant to lung cancer, cardiovascular diseases, and many neurological disorders, as they involve in various physiology and pathological processes in mitochondria cell apparatus. In this work, a new fluorescent probe CY-SO2 for bisulfate/sulfite based on hemicyanine dye is reported, which can used in solution detection with 56-fold fluorescence ratio (F-467 nm/F-380 nm) enhancement, fast response (completed within 90 s) and excellent sensitivity (DL 2.67 nM). The effect have been exhibited in real sugar samples tests. CY-SO2 also displayed fluorescent imaging of breast cancer cells (MCF-7) successfully, demonstrating that the probe is a novel mitochondria-targeted ratiometric fluorescent probe to image cellular SO2 derivatives.