Nanogold/mesoporous carbon foam-mediated silver enhancement for graphene-enhanced electrochemical immunosensing of carcinoembryonic antigen

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• 作者：Dajie Lin ; Jie Wu ; Huangxian Ju ; Feng Yan
• 关键词：Electrochemical sensors ; Immunoassay ; Signal amplification ; Silver deposition ; Mesoporous carbon foam ; Graphene
• 刊名：Biosensors and Bioelectronics
• 出版年：15 February, 2014
• 年：2014
• 卷：52
• 期：Complete
• 页码：153-158
• 全文大小：2409 K

文摘

Nanogold functionalized mesoporous carbon foam (Au/MCF) coupling with a signal amplification by C-Au synergistic silver enhancement was designed for sensitive electrochemical immunosensing of biomarker. The Au/MCF was prepared by in situ growth of nanogold on carboxylated MCF and used as a tracing tag to label signal antibody via the inherent interaction between protein and nanogold. The immunosensor was prepared by covalently immobilizing capture antibody on an electrochemically reduced graphene oxide/chitosan film modified glassy carbon electrode. Through a sandwich-type immunoreaction, Au/MCF tags were captured on the immunoconjugates to induce a silver deposition process. The electrochemical stripping signal of the deposited silver was used to monitor the immunoreaction. The Au/MCF-mediated silver enhancement along with the graphene-promoted electron transfer led to high detection sensitivity of carcinoembryonic antigen. Under optimal conditions, the proposed immunoassay method showed wide linear range from 0.05 pg mL^鈭? to 1 ng mL^鈭? and a detection limit down to 0.024 pg mL^鈭?. The newly designed amplification strategy holds great potential for ultrasensitive electrochemical biosensing of other analytes.