Amouzadeh Tabrizi, MahmoudAcedo Gallardo, Pablo2022-06-222022-06-222022-03Amouzadeh Tabrizi, M., & Acedo, P. (2022). An Electrochemical Impedance Spectroscopy-Based Aptasensor for the Determination of SARS-CoV-2-RBD Using a Carbon Nanofiber–Gold Nanocomposite Modified Screen-Printed Electrode. In Biosensors, 12(3), 142-1562079-6374https://hdl.handle.net/10016/35222Worldwide, 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 pmolcm-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.14eng© 2022 by the authors. Licensee MDPI, Basel, Switzerland.Atribución 3.0 EspañaElectrochemical impedance spectroscopyAptasensorSars-cov-2-rbdCNF–auNPresearch articleElectrónicahttps://doi.org/10.3390/bios12030142open access1423156Biosensors12AR/0000030919