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Voltammetric Immunoassay for the Detection of Protein Biomarkers

Haswell, Stephen J.; Dou, Yue-Hua; Wadhawan, Jay; Greenman, John

Authors

Stephen J. Haswell

Yue-Hua Dou



Abstract

A strategy for a fast (ca. 20 min), specific, electrochemical immunoassay for the cardiac biomarker creatine kinase (CK) and the human cytokine interleukin 10 (IL10) has been developed in this paper. The polyaniline modified gold surface formed from electrochemical reduction of diazonium salt supplies a solid substrate to link the activated carboxylic acid groups from the antibodies, which were labelled with ferrocene. The direct electrochemistry of ferrocene allows the analysis of protein markers with good sensitivity. The creatine kinase sensor demonstrates limit of detection of 0.5 pg mL−1 in a physiological Krebs-Henseleit solution. The anti-IL10 antibody retained fluorescence activity after further coupling to ferrocene and covalent immobilization on to a gold electrode, showing a linear detection range for IL-10 from 0.001 ng mL−1 to 50 ng mL−1 in PBS. We attribute the high sensitivity to the well-controlled modified surface which results in end–on antibodies that can specifically capture the antigen with ease.

Journal Article Type Article
Publication Date Feb 28, 2012
Journal ELECTROANALYSIS
Print ISSN 1040-0397
Electronic ISSN 1521-4109
Publisher Wiley
Peer Reviewed Peer Reviewed
Volume 24
Issue 2
Pages 264-272
APA6 Citation Haswell, S. J., Dou, Y., Wadhawan, J., & Greenman, J. (2012). Voltammetric Immunoassay for the Detection of Protein Biomarkers. Electroanalysis, 24(2), 264-272. doi:10.1002/elan.201100676
DOI https://doi.org/10.1002/elan.201100676
Keywords Biosensors; Ferrocene; Immunoassays; Protein biomarkers
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