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.

二氧化硫（SO2）是一种可能的内源性气体信号分子，已被发现与生物体内多种疾病相关。因此，开发有效的 SO2 检测方法具有重要的生理和病理学意义。本研究报道了一种基于迈克尔加成反应、用于监测亚硫酸氢盐的比率型近红外荧光探针 Cou-Rh。该探针由香豆素经酸催化环化反应制备。加入亚硫酸氢盐后，探针在 695 nm 处的荧光强度显著降低，而 550 nm 处的荧光增强。探针对多种生物相关分析物具有较高选择性，检测限达到纳摩尔水平。荧光成像进一步证实，Cou-Rh 能够检测活细胞和斑马鱼幼虫中的亚硫酸氢盐。结果表明，Cou-Rh 可作为研究二氧化硫生理功能的有效工具。