An Indirect Perfluorosulfonated Ionomer-Coated Electrochemical Immunosensor for the Detection of the Protein Human Chorionic Gonadotrophin

详细信息    查看全文

• 作者：Albert F. Chetcuti ; Danny K. Y. Wong ; and Margaret C. Stuart
• 刊名：Analytical Chemistry
• 出版年：1999
• 出版时间：September 15, 1999
• 年：1999
• 卷：71
• 期：18
• 页码：4088 - 4094
• 全文大小：116K
• 年卷期：v.71,no.18(September 15, 1999)
• ISSN：1520-6882

文摘

The development of an amperometric immunosensor forthe detection of human chorionic gonadotrophin (hCG)is described. In this immunosensor, Nafion was used toimmobilize an anti-hCG monoclonal antibody onto a glassycarbon electrode. A systematic study on the effects ofexperimental parameters such as the quantity of ethanolpresent in the Nafion solution, the percentage compositionof Nafion, the pH of the immobilization buffer, and theconcentration of antibody used for entrapment experiments on the binding between the immobilized antibodyand ¹²⁵I-labeled hCG has been carried out. Two immobilization methods, coimmobilization and adsorptionimmobilization, have then been attempted. A binding ofapproximately 3% was obtained in the former method,while 5.5% binding was achieved in the latter. On thebasis of these results, adsorption immobilization wasemployed to entrap antibody on the electrode surface. Asandwich assay was then developed for hCG in which theenzyme horseradish peroxidase was conjugated to asecond anti-hCG monoclonal antibody. The activity of theenzyme was determined electrochemically by the reduction of benzoquinone to hydroquinone. Binding of hCGto immobilized antibody determines the quantity of enzyme-conjugated antibody at the electrode surface, permittingthe quantification of hCG. By a standard additions calibration method of hCG performed in blank human serumsamples, the immunosensor exhibits a limit of linearityat 200 mIU mL^-1 and a detection limit of 11.2 mIU mL^-1(based on twice the standard deviation of the blanksolution).