Liu Siyao, Chen Qianqian, Wang Zhiming, Cao Tongcheng, Zhao Guohua, Zhou Yongxin
Department of Cardio-Thoracic Surgery, Institute of Translational Research, Tongji Hospital, Tongji University School of medicine, Shanghai 200065, People's Republic of China.
Analyst. 2019 Aug 5;144(16):4841-4847. doi: 10.1039/c9an00848a.
Polychlorinated biphenyl (PCB) detection in the environment is significant for both environmental protection and human health. Herein, a highly sensitive aptamer sensor has been established by employing a 2,3',5,5'-tetrachlorobiphenyl (PCB72) targeting aptamer as a highly specific recognition element and a gold/silver (Au@Ag) nanocomposite as the surface-enhanced Raman spectroscopy (SERS) substrate for detecting environmental PCB72. The Au@Ag nanoparticles (NPs) exhibit a strong SERS enhancement and provide an efficient substrate for immobilizing the PCB72 aptamer and Raman signal labelled molecule, 4-mercaptobenzoic acid (4-MBA). The targeted PCB72 could competitively bind with the PCB72 aptamer, resulting in a few aptamers sticking to the Au@Ag NPs and the "hot spot" strengthening effect of the substrate. Under optimal conditions, this aptamer sensor exhibits great performance with high sensitivity, excellent selectivity and stability for the monitoring of PCB72, which shows an excellent linear correlation ranging from 1 to 1000 pg mL-1 with a limit of detection of 0.3 pg mL-1. Furthermore, this aptamer assay exhibits high specificity and selectivity for PCB72 with the detection error of less than 0.27 for other PCBs and 0.21 for other interfering species, even if the coexisting interferents are 100-fold concentration in the system. Additionally, the recognition mechanism of the binding of aptamers to PCB72 is analyzed via UV-vis spectroscopy and molecular docking simulations, which suggest that PCB72 could insert into the aptamers. Furthermore, this method is successfully utilized for PCB72 detection in real water samples with a simple pre-treatment. In general, this work provides a new and effective method using an environmental aptamer sensor for rapid and sensitive PCB72 detection.
环境中多氯联苯（PCB）的检测对于环境保护和人类健康都具有重要意义。在此，通过使用靶向2,3',5,5'-四氯联苯（PCB72）的适体作为高度特异性识别元件，以及金/银（Au@Ag）纳米复合材料作为表面增强拉曼光谱（SERS）基底，建立了一种高灵敏度的适体传感器，用于检测环境中的PCB72。Au@Ag纳米颗粒（NPs）表现出强烈的SERS增强作用，并为固定PCB72适体和拉曼信号标记分子4-巯基苯甲酸（4-MBA）提供了有效的基底。目标PCB72可以与PCB72适体竞争性结合，导致一些适体附着在Au@Ag NPs上，并产生基底的“热点”增强效应。在最佳条件下，这种适体传感器在监测PCB72时表现出高灵敏度、优异的选择性和稳定性，在1至1000 pg mL-1范围内呈现出良好的线性相关性，检测限为0.3 pg mL-1。此外，这种适体检测方法对PCB72具有高特异性和选择性，对其他多氯联苯的检测误差小于0.27，对其他干扰物质的检测误差小于0.21，即使共存干扰物在系统中的浓度是其100倍。此外，通过紫外可见光谱和分子对接模拟分析了适体与PCB72结合的识别机制，结果表明PCB72可以插入适体中。此外，该方法通过简单的预处理成功应用于实际水样中PCB72的检测。总体而言，这项工作提供了一种新的有效方法，使用环境适体传感器快速、灵敏地检测PCB72。
