Integrated microfluidic systems with an immunosensor modified with carbon nanotubes for detection of prostate specific antigen (PSA) in human serum samples

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• 作者：Nancy V. Panini ; Germá ; n A. Messina ; Eloy Salinas ; Hé ; ctor Ferná ; ndez ; Julio Raba
• 关键词：Enzyme immunoassays ; Prostate specific antigen ; Amperometric immunosensor ; Horseradish peroxidase ; Microfluidic ; Flow injection analysis
• 刊名：Biosensors and Bioelectronics
• 出版年：2008
• 出版时间：28 February 2008
• 年：2008
• 卷：23
• 期：7
• 页码：1145-1151
• 全文大小：240 K

文摘

This paper describes the development of an immunosensor coupled to glassy carbon electrode (GCE) modified with multiwall carbon nanotubes (MWCNT) (CNT-GCE) integrated with microfluidic systems for rapid and sensitive quantification of prostate specific antigen (PSA) in human serum samples. Mouse monoclonal (5G6) to PSA antibodies were immobilized on a rotating disk. PSA in the serum sample are allowed to react immunologically with the immobilized anti-tPSA and horseradish peroxidase (HRP) enzyme-labeled second antibodies specific to PSA. HRP, in the presence of hydrogen peroxide (H₂O₂) catalyzes the oxidation of 4-tert-butylcatechol (4-TBC), whose back electrochemical reduction was detected on CNT-GCE at −0.15 V. The electrochemical detection can be done within 1 min and total assay time was 30 min. The calculated detection limits for electrochemical detection and the ELISA procedure are 0.08 and 0.5 μg L⁻¹, respectively and the intra- and inter-assay coefficients of variation were below 4.5 % . The electrochemical immunosensor showed higher sensitivity and lower time consumed than the standard spectrophotometric detection ELISA method, which shows potential for detecting PSA in clinical diagnosis.