A novel electrochemical immunoassay based on diazotization-coupled functionalized bioconjugates as trace labels for ultrasensitive detection of carcinoembryonic antigen
A novel electrochemical immunoassay based on diazotization-coupled functionalized bioconjugates as trace labels for ultrasensitive detection of carcinoembryonic antigen
复制标题
DOI：
10.1016/j.bios.2010.10.042
复制
发表时间：
2011-01-15
影响因子：
12.6
通讯作者：
Su, Huilan
中科院分区：
文献类型：
--
作者：
Jiang, Wen;Yuan, Ruo;Su, Huilan
本文报道了一种基于重氮化-偶联概念的信号放大策略的新型电化学免疫传感器，用于癌胚抗原（CEA）的超灵敏检测。它通过在4-氨基苯硫酚（4Atp）功能化的金电极界面上物理吸附单克隆抗CEA作为检测平台来工作。制备了偶氮-4Atp-偶联-噻吩（Thi）-偶联金纳米粒子（GNP），用于固定辣根过氧化物酶（HRP）和第二抗CEA，形成核-壳生物偶联物，用作电化学信号放大试剂。该免疫传感器的灵敏度得到了极大的提高：一是通过夹心免疫反应将大量的噻吩和HRP引入到电极表面，二是HRP作为增强剂催化过氧化氢氧化噻吩的反应，使还原峰电流大大增强。因此，基于生物缀合物的测定提供了用于检测痕量水平的CEA的扩增方法，并且导致低至0.7 pg/mL（在三倍信噪比下）的检测限，其远低于用于临床诊断的阈值2.5 ng/mL。对具有不同CEA浓度的临床血清样本进行了评估，结果与参考酶联免疫吸附试验（ELISA）获得的结果非常一致。(c)2010 Elsevier B. V.保留所有权利。
In this article, a novel sandwich-type electrochemical immunosensor based on the signal amplification strategy of diazotization-coupling concept for ultrasensitive detection of carcinoembryonic antigen (CEA) was reported. It operates through physisorption of monoclonal anti-CEA on 4-aminothiophenol (4Atp) functionalized gold electrode interface as the detection platform. Diazo-4Atp-coupled-thionine (Thi)-conjugated gold nanoparticles (GNPs) were prepared for immobilization of horseradish peroxidase (HRP) and secondary anti-CEA to form core-shell bioconjugates that were used as electrochemical signal amplification reagent. The sensitivity of the immunosensor was greatly amplified by a dual amplification: one is that a large number of thionine and HRP was introduced on the electrode surface through sandwich immunoreaction, the other is that HRP as enhancer could catalyze the oxidation reaction of thionine by H2O2, which results in great enhancement of the reduction peak current. Thus, the bioconjugates-based assay provided an amplification approach for detecting CEA at trace levels and led to a detection limit as low as 0.7 pg/mL(at a three times signal-to-noise ratio) that is well-below the threshold value of 2.5 ng/mL for clinical diagnosis. The assay was evaluated for clinical serum samples with various CEA concentrations and received in excellent accordance with the results obtained from the referenced enzyme-linked immunosorbent assay (ELISA). (c) 2010 Elsevier B.V. All rights reserved.