Insight into sulfur dioxide and its derivatives metabolism in living system with visualized evidences via ultra-sensitive fluorescent probe.

Sulfur dioxide (SO) and its derivatives have long been considered as hazardous environmental pollutants but commonly used as food additives in safe dose range. They also could be produced from biological metabolism process of sulfur-containing amino acids. However, their physiological roles remain extremely obscure mainly due to lack of efficient tools for monitoring and imaging strategy establishment. Furthermore, most of current studies of this aspect focus on novel probe design or just imaging them rather than on the ins and outs. Therefore, there is a high significance of establishing highly sensitive detection strategy for monitoring SO derivatives in living systems, food and environment. Herein, we design a fluorescent probe MS-Bindol for sensitively detecting SO derivatives with a low detection limit (0.2 nM). We have established an imaging strategy for investigation of SO derivatives metabolism in living cells and zebrafish, providing visualize evidences and verified that SO derivatives could be synthetized from thiosulfate and glutathione(GSH) and be hardly consumed by using sulfite oxidase inhibitors (ferricyanide or arsenite). Moreover, the probe also exhibits excellent practicability in food as well as environmental samples. Our studies may help biologist for better understanding SO derivatives metabolism and deeply explore their physiological roles in biological systems.