Key Lab of Fluorine and Silicon for Energy Materials and Chemistry of Ministry of Education, College of Chemistry and Chemical Engineering, Jiangxi Normal University, Nanchang 330022, China.
Anal Chem. 2022 Apr 5;94(13):5352-5358. doi: 10.1021/acs.analchem.1c05426. Epub 2022 Mar 20.
Two kinds of two-dimensional (2D) covalent-organic frameworks (COF) were used to construct a sandwich-type electrochemical immunosensor for a proof-of-concept study. Vinyl-functionalized COFTab-Dva could be linked with Ab1 by the thiol-ene "click" reaction. Electroactive COFTFPB-Thi was modified with gold nanoparticles (AuNPs) to ensure the successful connection with Ab2 through Au-S bond. Meanwhile, electroactive COFTFPB-Thi was used to as signal probe to realize both the detection of carcinoembryonic antigen (CEA) and the amplification of detection signal. In detection process of the sandwich-type electrochemical immunosensor, glassy carbon electrode (GCE) was modified with 2D COFTab-Dva first then connected with Ab1 by the thiol-ene "click" reaction, next quantitative CEA was captured, followed by specificially capturing signal probe of Ab2/AuNPs/COFTFPB-Thi where AuNPs acted as nanocarriers of Ab2 and COFTFPB-Thi served as the signal producers. As the amount of CEA was increased, the amount of signal probe captured to the electrode was also increased, and the peak signal intensity of the redox reaction of COFTFPB-Thi was enhanced accordingly. Thus, the quantitative detection of CEA could be realized according to the peak signal intensity of electroactive COFTFPB-Thi. The electrochemical immunosensor owned wide detection range of 0.11 ng/mL-80 ng/mL, low detection limit of 0.034 ng/mL and good practicability. This study opens up a new revelation for quantitative detection of CEA using electroactive COF as enhanced signal probe.
两种二维（2D）共价有机骨架（COF）被用于构建三明治型电化学免疫传感器，以进行概念验证研究。乙烯基功能化的 COFTab-Dva 可以通过硫醇-烯“点击”反应与 Ab1 连接。电化学活性的 COFTFPB-Thi 用金纳米粒子（AuNPs）修饰，以确保通过 Au-S 键与 Ab2 成功连接。同时，电化学活性的 COFTFPB-Thi 被用作信号探针，以实现癌胚抗原（CEA）的检测和检测信号的放大。在三明治型电化学免疫传感器的检测过程中，玻碳电极（GCE）首先用 2D COFTab-Dva 修饰，然后通过硫醇-烯“点击”反应与 Ab1 连接，接着定量捕获 CEA，然后特异性地捕获 Ab2/AuNPs/COFTFPB-Thi 的信号探针，其中 AuNPs 作为 Ab2 的纳米载体，COFTFPB-Thi 作为信号产生体。随着 CEA 量的增加，被捕获到电极上的信号探针量也增加，COFTFPB-Thi 的氧化还原反应的峰信号强度相应增强。因此，可以根据电化学活性 COFTFPB-Thi 的峰信号强度实现 CEA 的定量检测。电化学免疫传感器具有较宽的检测范围（0.11 ng/mL-80 ng/mL）、较低的检测限（0.034 ng/mL）和良好的实用性。这项研究为使用电化学活性 COF 作为增强信号探针进行 CEA 的定量检测开辟了新的思路。
