An Electrochemical Impedance Spectroscopy-Based Aptasensorfor the Determination of SARS-CoV-2-RBD Using a CarbonNanofiber&-Gold Nanocomposite ModifiedScreen-Printed Electrode Articles uri icon

publication date

  • March 2022

start page

  • 142

end page

  • 156


  • 3


  • 12

International Standard Serial Number (ISSN)

  • 2079-6374


  • Worldwide, human health is affected by severe acute respiratory syndrome coronavirus
    2 (SARS-CoV-2). Hence, the fabrication of the biosensors to diagnose SARS-CoV-2 is critical. In
    this paper, we report an electrochemical impedance spectroscopy (EIS)-based aptasensor for the
    determination of the SARS-CoV-2 receptor-binding domain (SARS-CoV-2-RBD). For this purpose, the
    carbon nanofibers (CNFs) were first decorated with gold nanoparticles (AuNPs). Then, the surface of
    the carbon-based screen-printed electrode (CSPE) was modified with the CNF–AuNP nanocomposite
    (CSPE/CNF–AuNP). After that, the thiol-terminal aptamer probe was immobilized on the surface of
    the CSPE/CNF–AuNP. The surface coverage of the aptamer was calculated to be 52.8 pmol cm􀀀2.
    The CSPE/CNF–AuNP/Aptamer was then used for the measurement of SARS-CoV-2-RBD by using
    the EIS method. The obtained results indicate that the signal had a linear–logarithmic relationship in
    the range of 0.01–64 nM with a limit of detection of 7.0 pM. The proposed aptasensor had a good
    selectivity to SARS-CoV-2-RBD in the presence of human serum albumin; human immunoglobulins
    G, A, and M, hemagglutinin, and neuraminidase. The analytical performance of the aptasensor
    was studied in human saliva samples. The present study indicates a practical application of the
    CSPE/CNF-AuNP/Aptamer for the determination of SARS-CoV-2-RBD in human saliva samples
    with high sensitivity and accuracy.


  • Electronics


  • electrochemical impedance spectroscopy; aptasensor; cnf–aunp; sars-cov-2-rbd