Rapid detection of SO2 in living cells and zebrafish by using an efficient near-infrared ratiometric fluorescent probe with large emission shift

Abstract

Sulfur dioxide (SO2), a possible endogenous gaseous signaling molecule, has been found to be correlated with various diseases in living organisms. Thus, the development of effective methods for detection of SO2 are of great physiological and pathological significance. In this work, we report a ratiometric NIR fluorescent probe Cou-Rh for monitoring bisulfite on basis of Michael addition reaction. This probe is prepared from coumarin by acid-catalyzed cyclization reaction. The addition of bisulfite results in a significant decrease of fluorescence intensity at 695 nm and enhancement at 550 nm. The probe also displays high selectivity over various biologically related analytes with nanomolar limit of detection. What’s more, fluorescence imaging further confirms that the probe is capable of detecting bisulfite in living cells and zebrafish larvae. The results demonstrate that probe Cou-Rh can be employed for a useful scaffold to study the physiological function of sulfur dioxide.