Gold nanolabels and enzymatic recycling dual amplification-based electrochemical immunosensor for the highly sensitive detection of carcinoembryonic antigen

作     者：ZHANG YuYong XIANG Yun CHAI YaQin YUAN Ruo QIAN XiaoQing ZHANG HaiXia CHEN Ying SU Jiao XU Jin 

作者机构：Education Ministry Key Laboratory on Luminescence and Real-Time AnalysisSchool of Chemistry and Chemical EngineeringSouthwest UniversityChongqing 400715China 

出 版 物：《Science China Chemistry》 (中国科学(化学英文版))

年 卷 期：2011年第54卷第11期

页      面：1770-1776页

核心收录：

学科分类：1002[医学-临床医学] 100214[医学-肿瘤学] 10[医学] 

基　　金：supported by the National Natural Science Foundation of China (20905062 & 20675064) the Natural Science Foundation Project of Chongqing City (CSTC-2009BB5003 & CSTC-2009BA1003) China Post-doctoral Science Foundation (20090460715) research funds from Southwest University (SWUB2008078 & XDJK2009B013) 

主　　题：amplification electrochemical immunosensor carcinoembryonic antigen redox-recycling 

摘      要：A sensitive electrochemical immunoassay system for the detection of a protein tumor biomarker through a dual amplified strategy was reported. Firstly, this protocol involves in the electropolymerization of o-aminobenzoic acid (o-ABA) on a glass carbon electrode (GCE). Subsequently, capture anti-CEA (Abl) is covalently linked to poly(o-ABA) (PAB) film, via N-(3-dimethylamminopropyl)-N -ethylcarbodiimide hydrochloride (EDC), and N-hydroxysulfosuccinimid sodium salt (NHS) activation of the carboxyl groups and surface blocking with ethanolamine. Later, the target, carcinoembryonic antigen (CEA), is sandwiched between an electrode surface confined Ab1 and the alkaline phosphatase-labeled signal anti-CEA antibodies conjugated with gold nanoparticles (Ab2-ALP-AuNP bioconjugates). The dual biocatalytic signal amplification for CEA monitoring is achieved by coupling the numerous enzymes loaded on the AuNPs with redox-recycling of the enzymatic products in the presence of the secondary enzyme and the corresponding substrate. The novel dramatic signal amplification strategy, exhibits a good linearity at the studied concentration range from 0.005 to 50 ng mL-1 towards CEA with a detection limit of 2 pg mL-1 (S/N=3). There is a 5-100-fold improvement in detection limit compared to other similar studies. The developed dual signal amplified strategy shows good selectivity, regeneration, stability and acceptable reproducibility. Therefore, the signal amplification approach holds great potential applications in detection of ultra-trace protein biomarkers.