Fluorescence Detection of Tetracycline Based on Carbon Dots

本文以柠檬酸和尿素为原料，通过微波法一步制备出荧光性能良好的碳点(CDs)。基于四环素与CDs之间的相互作用，构建了一种特异性检测四环素的荧光探针。采用紫外–可见吸收光谱和荧光光谱对CDs和四环素进行表征，发现四环素的紫外吸收光谱与CDs的荧光激发光谱之间存在的重叠区域，可能是由于CDs与四环素之间产生了荧光内滤效应(IFE)导致CDs荧光猝灭。讨论荧光体系溶剂组成、pH等单变量因素对CDs荧光猝灭效果的影响，在最佳检测条件下探究CDs荧光强度与四环素浓度之间的线性关系。实验结果表明，四环素的检出限为1.1 × 10−9 mol/L。该方法选择性好、灵敏度高，在特异性检测四环素领域具有较好前景。In this paper, carbon dots (CDs) with good fluorescence properties were prepared in one step by microwave method using citric acid and urea as raw materials. Based on the fluorescence quenching of CDs by tetracycline, a fluorescence probe was constructed to detect tetracycline specifically. CDs and tetracycline were characterized by UV-VIS absorption spectra and fluorescence spectra. It was found that the UV absorption spectra of tetracycline overlapped with the fluorescence excitation spectra of CDs to a large extent, which may be due to the fluorescence internal filtration effect (IFE) between CDs and tetracycline. The influence of univariate factors such as solvent composition and pH on the fluorescence quenching effect of CDs was discussed, and the linear relationship between fluorescence intensity of CDs and tetracycline concentration was investigated under the optimal detection conditions. The experimental results showed that the detection limit of tetracycline was 1.1 × 10−9 mol/L. The method has good selectivity and high sensitivity, and has a good prospect in the field of specific detection of tetracycline.