Ultrasensitive Immunoassay Based on Amplified Inhibition of the Electrochemical Stripping Signal of Silver Nanocomposite by Silica Nanoprobe

Authors

  • Cuiying Yin,

    1. Hubei Key Laboratory of Pollutant Analysis and Reuse Technology, Department of Chemistry, Hubei Normal University, Huangshi 435002, P. R. China tel: +86-714-6515602; fax: +86-714-6573832
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  • Guosong Lai,

    Corresponding author
    1. Hubei Key Laboratory of Pollutant Analysis and Reuse Technology, Department of Chemistry, Hubei Normal University, Huangshi 435002, P. R. China tel: +86-714-6515602; fax: +86-714-6573832
    • Hubei Key Laboratory of Pollutant Analysis and Reuse Technology, Department of Chemistry, Hubei Normal University, Huangshi 435002, P. R. China tel: +86-714-6515602; fax: +86-714-6573832

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  • Li Fu,

    1. Faculty of Life and Social Sciences, Swinburne University of Technology, Hawthorn VIC 3122, Australia
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  • Haili Zhang,

    1. Hubei Key Laboratory of Pollutant Analysis and Reuse Technology, Department of Chemistry, Hubei Normal University, Huangshi 435002, P. R. China tel: +86-714-6515602; fax: +86-714-6573832
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  • Aimin Yu

    1. Hubei Key Laboratory of Pollutant Analysis and Reuse Technology, Department of Chemistry, Hubei Normal University, Huangshi 435002, P. R. China tel: +86-714-6515602; fax: +86-714-6573832
    2. Faculty of Life and Social Sciences, Swinburne University of Technology, Hawthorn VIC 3122, Australia
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Abstract

A silver nanocomposite was one-step synthesized in chitosan solution and used to prepare an immunosensor with the aid of gold nanoparticles (Au NPs) assembly. The Ag NPs at the immunosensor exhibited sensitive electrochemical stripping signal in KCl solution. After a sandwich immunoreaction, the current response of the immunosensor decreased due to the formation of antibody-antigen immunocomplex on its surface, which was greatly amplified by the captured silica nanoprobes and thus enabled an ultrasensitive electrochemical immunoassay method. This method showed excellent analytical performance for human IgG measurement including wide linear range, low detection limit, cheap cost, satisfactory reproducibility and stability.

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