Electrochemical Aptasensor Based on ZnO Modified Gold Electrode

Authors

  • Gennady Evtugyn,

    1. Analytical Chemistry Department, Kazan Federal University, 18 Kremlevskaya Street, Kazan, 420008, Russian Federation
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  • Uljana Cherkina,

    1. Analytical Chemistry Department, Kazan Federal University, 18 Kremlevskaya Street, Kazan, 420008, Russian Federation
    2. Department of Nuclear Physics and Biophysics, Comenius University, Mlynska dolina F1, 842 48 Bratislava, Slovakia
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  • Anna Porfireva,

    1. Analytical Chemistry Department, Kazan Federal University, 18 Kremlevskaya Street, Kazan, 420008, Russian Federation
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  • Jürgen Danzberger,

    1. Institute of Biophysics, Johannes Kepler University Linz, Gruberstrasse 40, 4020 Linz, Austria
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  • Andreas Ebner,

    1. Institute of Biophysics, Johannes Kepler University Linz, Gruberstrasse 40, 4020 Linz, Austria
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  • Tibor Hianik

    Corresponding author
    1. Department of Nuclear Physics and Biophysics, Comenius University, Mlynska dolina F1, 842 48 Bratislava, Slovakia
    • Department of Nuclear Physics and Biophysics, Comenius University, Mlynska dolina F1, 842 48 Bratislava, Slovakia
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Abstract

We developed an electrochemical thrombin aptasensor based on ZnO nanorods functionalized by electrostatically adsorption of 30-mer DNA aptamers. The sensor surface was characterized by AFM and SEM. The surface layer assembling was optimized using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) with ferricyanide ions as redox markers. The peak current of the ferricyanide and the charge transfer resistance gradually decreased with increasing concentration of thrombin in the range from 3 pM to 100 nM due to formation of aptamer-thrombin complexes and slower diffusion of the marker ions through the surface layer. At optimal conditions, a limit of detection (LOD) of 3 pM for EIS measurements and 10 pM for CV response was calculated from the S/N=3.

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