pH敏感的香豆素并吡啶荧光染料用于试纸测试和细胞成像OA

Objective:We developed a pH-sensitive fluorescent dye based on the coumarin-pyridine(Cou-py)structure to detect alkaline pH,which enables cell imaging and test strip detection.Methods:Cou-py was synthesized by sequentially reacting 4-methyl-7-diethylaminocoumarin with the Vilsmeier-Haack reagent and aqueous ammonia.Its pH-responsive performance was systematically investigated in solution,on test strip,and in cellular environment under alkaline conditions.Results:Cou-py was successfully synthesized,and absorption and fluorescence spectroscopic analyses demonstrated that its absorption peak exhibited a blue shift from 405 nm to 365 nm under alkaline conditions.The solution could be observed from yellow to colorless by naked eyes,accompanied by a gradual enhancement of fluorescence emission at 465 nm with increasing pH,showing a 28-fold enhancement at pH 10.5 versus pH 6.5(linear range:pH 7.0～10.0,R2=0.995).Cell experiments demonstrated that Cou-py exhibited low cytotoxicity and excellent photostability,successfully visualizing the alkaline cellular environment.Test strip application demonstrated that Cou-py displayed a blue fluorescence"turn-on"response triggered by alkaline conditions,achieving rapid visual detection.Conclusion:A pH-sensitive fluorescent dye,Cou-py,was proposed which not only exhibited a dual colorimetric and fluorescent response under alkaline conditions in solution systems,but also was capable of imaging the alkaline cellular environment.This dye could be loaded onto test strip for quick and convenient detection of alkaline pH through blue fluorescence"turn-on".This study provides an efficient tool for monitoring intracellular alkaline environments.