A novel fluorescent probe for rapid detection of sulfur dioxide in living cells

Abstract Sulfur dioxide is one of the reactive sulfur species, which has significant physiological functions in cells. Some physiological processes are closely related to SO 2 in organisms, and the high concentration of SO 2 in living cells can cause many diseases. In order to investigate the unique function of SO 2 at the subcellular level, developing a molecular tool which could detect of SO 2 within organelles is imperative. Hence, we developed a cationic dye named HQ‐SO 2 as a new fluorescent probe to specifically monitor SO 2 , which was easy to obtain through one‐step reaction. It took Michael addition reaction as the mechanism of reaction for detection of SO 2 . In addition, this probe showed a series of highly favorable properties such as rapid response rate, low cytotoxicity, high selectivity, low detection limit, and good photostability, which enabled the probe to track SO 2 in living cells.