A BODIPY‐Hemicyanine‐Based Water‐Soluble Dual‐Color Fluorescence Probe for Colorimetric Monitoring of Intracellular Endogenous Sulfur Dioxide and Bioimaging Applications

We conjugated aldehyde‐BODIPY with the water‐soluble iodopropionic‐acid‐hemicyanine to develop a new dual‐color fluorescence probe (BHC) for selective and sensitive monitoring of endogenous SO 2 for the first time. Through excellent water solubility and the unique nucleophilic addition reaction, BHC has a higher selectivity for the colorimetric monitoring of SO 2 than other related substances. The resulting probe BHC has red emission, and can be converted to green emission after reacting with SO 2 . Then the dual‐color fluorescence probe was further applied to image intracellular endogenous generated SO 3 2− /HSO 3 − by the metabolism of living cells with satisfactory results. This strategy provides a new tool for revealing the metabolism of SO 3 2− /HSO 3 − and quantifying their distribution in living cells.