Fast scan voltammetry-derived ultrasensitive Faraday cage-type electrochemical immunoassay for large-size targets
Fast scan voltammetry-derived ultrasensitive Faraday cage-type electrochemical immunoassay for large-size targets
复制标题
快速扫描伏安法衍生的超灵敏法拉第笼式电化学免疫分析法，适用于大尺寸靶标
DOI：
10.1016/j.bios.2020.112277
复制
发表时间：
2020-09-01
影响因子：
12.6
通讯作者：
Su, Xiurong
中科院分区：
文献类型：
--
作者：
Wang, Tao;Lin, Han;Su, Xiurong
电化学免疫分析（ECIA）是一种快速、现场检测多种分析物的重要方法。然而，其检测灵敏度受到传统贴片式传感器构建模式的极大限制，特别是在大尺寸目标如微米级病原菌的情况下。为此，我们开发了一种基于功能化二维导电纳米材料的法拉第笼式传感模式，构建了一种电化学免疫传感器，该传感器可以为组装大量电化学信号标记物提供平台，并为电极表面的扩展提供良好的支撑。电子可以在电极和导电纳米材料之间流动，然后与固定的所有信号标记交换，而不受非导电大尺寸目标的阻碍，导致显著的信号放大。此外，第一次集成与快速扫描阳极溶出伏安法（FSASV）允许进一步增强ECIA信号。利用FSASV的法拉第笼式传感模式和100 V s（-1）的高扫描速率，对微米级致病菌副溶血性弧菌（VP）的电化学信号进行了数百倍的有效放大，定量限（LOQ）为1 CFU mL（-1）。这项工作有助于推进下一代ECIA或其他具有高灵敏度的氧化还原相关免疫测定的设计，特别是对于大尺寸靶标。
Electrochemical immunoassay (ECIA) is an important method for rapid, on-site detection of various analytes. However, its detection sensitivity is greatly limited by the traditional sandwich-type sensor construction mode, especially in the case of large-size targets such as pathogenic bacteria with micron size. Herein, we developed a Faraday cage-type sensing mode to build an electrochemical immunosensor based on a functionalized two-dimensional conductive nanomaterial, which could provide a platform to assemble a large number of electrochemical signal labels and a good support for the expansion of electrode surface. Electrons could flow between the electrode and the conductive nanomaterial and then exchange with all signal labels immobilized without the hindrance of non-conductive large-size targets, resulting in a significant signal amplification. In addition, first time integration with fast scan anodic stripping voltammetry (FSASV) allowed for further enhanced ECIA signal. Benefitting from both the Faraday cage-type sensing mode and the high scan rate 100 V s(-1) of FSASV, electrochemical signal was effectively amplified several hundred times with a limit of quantitation (LOQ) of 1 CFU mL(-1) for micron-sized pathogenic bacteria Vibrio parahemolyticus (VP). This work sheds lights on advancing the design of next-generation ECIA or other redox-related immunoassays with ultrahigh sensitivity, especially for large-size targets.