An Electrochemical Impedance Spectroscopy-Based Aptasensor for the Determination of SARS-CoV-2-RBD Using a Carbon Nanofiber-Gold Nanocomposite Modified Screen-Printed Electrode

• Published in: Biosensors (Basel) Vol. 12; no. 3; p. 142
• Main Authors: Amouzadeh Tabrizi, Mahmoud, Acedo, Pablo
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 25-02-2022; MDPI
• Subjects: Antigens; Aptamers; aptasensor; Biosensors; Carbon; Carbon fibers; CNF–AuNP; Coronaviruses; Electrochemical impedance spectroscopy; Electrochemistry; Electrodes; Exo-a-sialidase; Fabrication; Fourier transforms; Gold; Hemagglutinins; Human serum albumin; Immunoglobulins; Impedance; Methods; Nanocomposites; Nanofibers; Nanoparticles; Potassium; Proteins; Saliva; SARS-CoV-2-RBD; Selectivity; Serum albumin; Severe acute respiratory syndrome; Severe acute respiratory syndrome coronavirus 2; Sodium; Spectroscopy; Spectrum analysis; Standard deviation; Statistical analysis; United States > US; Spain; electrochemical impedance spectroscopy; CNF–AuNP; SARS-CoV-2-RBD; aptasensor
• ISSN: 2079-6374; 2079-6374
• DOI: 10.3390/bios12030142

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
. 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.