Han Ting, Wang Shaozhen, Sheng Feifan, Wang Sicheng, Dai Tianyue, Zhang Xiaojun, Wang Guangfeng
Key Laboratory of Chem-Biosensing, Anhui Province; Key Laboratory of Functional Molecular Solids, Anhui Province; College of Chemistry and Materials Science, Center for Nano Science and Technology, Anhui Normal University, Wuhu 241000, PR China.
Analyst. 2020 May 18;145(10):3598-3604. doi: 10.1039/d0an00065e.
In this work, we demonstrated an ultrasensitive detection platform for polychlorinated biphenyls (PCBs) based on DNA microcapsules and a nonlinear hybridization chain reaction (NHCR). In the process, first, electrochemical signal molecules (Methylene Blue, MB) were sealed in the prepared DNA microcapsules. In the presence of PCB-72, DNA microcapsules could be dissociated with the conjugation of the aptamer and target, and meanwhile, the released DNA strand could initiate the NHCR and trigger the chain branching growth of DNA dendrimers. Because the released MBs were intercalated into the DNA dendrimer, enhanced electrochemical responses could be detected. This method exhibited ultrahigh sensitivity to PCB-72 with a detection limit of 0.001 ng mL-1. Furthermore, the present aptasensor was also capable of discriminating different PCB congeners. Therefore, the devised label-free and enzyme-free amplification electrochemical aptasensor strategy has great potential for the detection of PCB-72 in real samples, and this strategy may also become an attractive alternative for sensitive and selective small molecule, protein, nucleic acid and nuclease activity detection.
在这项工作中，我们展示了一种基于DNA微胶囊和非线性杂交链式反应（NHCR）的多氯联苯（PCBs）超灵敏检测平台。在此过程中，首先，将电化学信号分子（亚甲基蓝，MB）封装在制备好的DNA微胶囊中。在存在PCB - 72的情况下，DNA微胶囊会因适配体与靶标的结合而解离，同时，释放出的DNA链可引发NHCR并触发DNA树枝状聚合物的链分支生长。由于释放出的MB插入到DNA树枝状聚合物中，因此可检测到增强的电化学响应。该方法对PCB - 72表现出超高灵敏度，检测限为0.001 ng mL-1。此外，当前的适配体传感器还能够区分不同的PCB同系物。因此，所设计的无标记、无酶扩增电化学适配体传感器策略在实际样品中检测PCB - 72具有巨大潜力，并且该策略也可能成为灵敏且选择性检测小分子、蛋白质、核酸和核酸酶活性的有吸引力的替代方法。
