CAS Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research (YIC), Chinese Academy of Sciences (CAS), Shandong Key Laboratory of Coastal Environmental Processes, YICCAS, Yantai, Shandong, 264003, PR China; University of Chinese Academy of Sciences, Beijing, 100049, PR China.
CAS Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research (YIC), Chinese Academy of Sciences (CAS), Shandong Key Laboratory of Coastal Environmental Processes, YICCAS, Yantai, Shandong, 264003, PR China.
Biosens Bioelectron. 2022 Mar 15;200:113923. doi: 10.1016/j.bios.2021.113923. Epub 2021 Dec 30.
We introduce here a versatile approach to read out potentiometric aptasensors by electrogenerated chemiluminescence (ECL), which can amplify the small potential changes induced by the bacterial concentrations via ECL signals. In the present system, the electrode modified with single-walled carbon nanotubes (SWCNTs) and aptamer molecules acts as the reference electrode and is placed in the sample solution for sensing the bacterial concentration changes, while the Ru(bpy) modified gold electrode serves as the working electrode for generating ECL signals and is placed in the detection solution containing tripropylamine (TPA) spatially separated from the sample solution by a salt bridge. Ru(bpy) is immobilized on the gold electrode's surface for enhancement of luminous efficiency and reduction of reagent consumption. A moving-part-free fluid flowing system is introduced to promote the mass transport of TPA from the detection solution to the surface of the ECL generating electrode. When a constant potential is imposed between the working and reference electrodes, the potential changes at the SWCNTs-aptamer modified electrode induced by the bacterial concentrations can modulate the potentials at the Ru(bpy) modified electrode, thus generating the ECL signals. The developed sensing strategy shows a highly sensitive response to E. coli O157: H7 in the linear range of 5-1000 CFU mL with a low detection limit of 2 CFU mL. We believe that the proposed approach is promising to develop aptasensors for sensitive detection of bacterial cells.
我们在这里介绍了一种多功能的方法来读取电化学生物发光（ECL）适配体传感器，它可以通过 ECL 信号放大由细菌浓度引起的小电位变化。在本系统中，修饰有单壁碳纳米管（SWCNTs）和适配体分子的电极作为参比电极并置于样品溶液中以感测细菌浓度变化，而修饰有 Ru(bpy)的金电极作为工作电极用于产生 ECL 信号并置于含有三丙胺（TPA）的检测溶液中，通过盐桥与样品溶液隔开。Ru(bpy)固定在金电极表面以提高发光效率并减少试剂消耗。引入无移动部件的流体流动系统以促进 TPA 从检测溶液向 ECL 产生电极表面的质量传输。当在工作电极和参比电极之间施加恒定电势时，细菌浓度引起的 SWCNTs-适配体修饰电极的电势变化可以调制 Ru(bpy)修饰电极的电势，从而产生 ECL 信号。所开发的传感策略对 E. coli O157: H7 在 5-1000 CFU mL 的线性范围内表现出高度灵敏的响应，检测限低至 2 CFU mL。我们相信，所提出的方法有望开发用于细菌细胞灵敏检测的适配体传感器。
