基于碳点-铕的比率荧光探针可视化检测四环素

Ratiometric Fluorescence Assay for Visual Detection of Tetracycline Residues based on the Complex of Carbon Dots and Europium

结合四环素对碳点(CDs)的荧光猝灭及对铕离子(Eu^3+)的荧光增强作用,建立了一种肉眼可辨的比率荧光分析方法用于水样中四环素残留的便捷检测.通过优化CDs/Eu^3+比例、溶液pH值等实验条件,使检测体系对四环素的荧光响应呈现由蓝色→粉色→红色的颜色转变过程,易于通过肉眼进行分辨和半定量分析.实验结果表明,2种荧光探针响应比(I618/I440)的对数值与四环素的浓度在20~100nmol/L范围内呈线性关系,方法的检出限为1nmol/L.将该方法应用于江水样品中四环素的加标检测,获得了较好结果.

On combination of the fluorescence quenching effect of tetracycline on carbon dots(CDs)with the fluorescence enhancement effect of tetracycline on europium ions(Eu^3+),a visual ratiometric fluorescence assay was developed for the convenient detection of tetracycline residues.By optimizing the CDs/Eu3+ratio,pH and other experimental conditions,the detection system exhibited a distinct chang of fluorescence color(blue→pink→red)in response to tetracycline,leading to a convenient identification and semi quantitation by the naked eye.The results showed that the logarithmic values of I618/I440 was linearly related to the concentration of tetracycline in the range of 20-100 nmol/L,and the detection limit of this work was 1 nmol/L.Recovery experiment suggested the proposed method fine results for the determination of tetracycline in water samples.