CQDs/Eu^(3+)比率荧光探针的制备及对四环素的检测

Preparation of CQDs/Eu^(3+) Ratiometric Fluorescent Probe for Visual Detection of Tetracycline

以碳量子点(CQDs)和铕离子(Eu^(3+))为荧光基团,构建比率荧光探针(CQDs/Eu^(3+)),用于四环素(TC)的可视化检测。在380 nm波长激发下,CQDs/Eu^(3+)在439 nm处存在较强的蓝色荧光峰,在616 nm处存在较弱的红色荧光峰,当TC存在时,基于内滤效应439 nm处CQDs的荧光峰强度降低;基于天线效应616 nm处Eu^(3+)荧光强度增强。研究优化了CQDs和Eu^(3+)比例、响应时间、稳定性等实验条件。结果表明:该比率荧光探针对TC具有特异性识别能力,荧光强度比(F_(616)/F_(439))与不同浓度TC(0~50μM)之间存在良好的线性关系,对TC最低检测限为0.68μM,随着TC的加入,比率荧光探针溶液在紫外灯下的颜色由蓝色逐渐变成红色并成功用于牛奶中TC检测,回收率为92.5%~114.8%。还制备了TC检测试纸,可快速用于对TC的可视化试纸检测。

A ratiometric fluorescent probe was constructed with carbon quantum dots (CQDs) and europium ions (Eu^(3+)) as a fluorophore for the visual detection of teracycline (TC).In this ratiometric probe,CQDs/Eu^(3+)has an intense blue fluorescence peak at439 nm and a weak red fluorescence peak at 616 nm under the excitation of 380 nm wavelength.The fluorescence peak intensity of CQDs at 439 nm gradually decreases based on the inner filter effect.The fluorescence intensity of Eu^(3+)at 616 nm increases due to an antenna effect with the addition of TC.The experimental factors,such as CQDs and Eu^(3+)ratio,response time,stability,etc.,were optimized.The results show that the ratio fluorescent probe has a specific recognition ability for TC.A linear relationship between the fluorescence intensity ratio(F_(616)/F_(439)) and different concentrations of TC (0–50μM) was established with a detection limit of 0.68μM.With the addition of TC,the color of the ratio fluorescent probe solution under ultraviolet light gradually changes from blue to red and is used for the detection of TC in milk with the recoveries ranging from 92.5%to 1 14.8%.In addition,a TC test paper was also prepared,which can be quickly used for a visual test paper detection of TC.