Amperometric sandwich immunoassay for the carcinoembryonic antigen using a glassy carbon electrode modified with iridium nanoparticles, polydopamine and reduced graphene oxide

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• 作者：Luyang Miao ; Lei Jiao ; Juan Zhang ; He Li
• 关键词：Immunosensor ; Sandwich ; type ; Tumor biomarker ; Immobilization ; Electrochemical signal amplification ; Electrochemical impedance spectroscopy ; Hexacyanoferrate ; Nyquist plot ; Hydrogen peroxide ; Serum analysis
• 刊名：Microchimica Acta
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：184
• 期：1
• 页码：169-175
• 全文大小：
• 刊物类别：Chemistry and Materials Science
• 刊物主题：Nanochemistry; Nanotechnology; Characterization and Evaluation of Materials; Analytical Chemistry; Microengineering;
• 出版者：Springer Vienna
• ISSN：1436-5073
• 卷排序：184

文摘

The authors describe a sandwich-type electrochemical immunoassay for sensitive determination of the carcinoembryonic antigen (CEA). It is based on the use of iridium nanoparticles (Ir NPs) acting as electrochemical signal amplifier on the surface of a glassy carbon electrode. At first, polydopamine-reduced graphene oxide (PDA-rGO) was employed to immobilize primary antibody (Ab₁) against CEA. Secondly, Ir-NPs were used as a support for the immobilization of secondary antibody (Ab₂) to afford signal labels. The large surface area of PDA-rGO and the excellent electro-oxidative H₂O₂-sensing properties of Ir NPs result in a sensitive assay for CEA. Operated best at a working voltage of −0.6 V (vs. SCE), the assay has a linear range that extends from 0.5 pg⋅mL−1 to 5 ng·mL−1, and the lower detection limit is 0.23 pg⋅mL−1. The immunosensor displays satisfactory reproducibility and stability, thus demonstrating a reliable immunoassay strategy for tumor biomarkers. It was applied to the determination of CEA in spiked serum samples.