Sensitive sandwich-type electrochemical SARS-CoV‑2 nucleocapsid protein immunosensor

Ceren Karaman; Bahar Bankoğlu Yola; Onur Karaman; Necip Atar; İlknur Polat; Mehmet Lütfi Yola

doi:10.1007/s00604-021-05092-6

Sensitive sandwich-type electrochemical SARS-CoV‑2 nucleocapsid protein immunosensor

Mikrochim Acta. 2021 Nov 23;188(12):425. doi: 10.1007/s00604-021-05092-6.

Authors

Ceren Karaman¹, Bahar Bankoğlu Yola², Onur Karaman³, Necip Atar⁴, İlknur Polat⁵, Mehmet Lütfi Yola⁶

Affiliations

¹ Department of Electricity and Energy, Vocational School of Technical Sciences, Akdeniz University, Antalya, Turkey.
² Science and Technology Application and Research Laboratory, Iskenderun Technical University, Hatay, Turkey.
³ Department of Medical Imaging Techniques, Vocational School of Health Services, Akdeniz University, Antalya, Turkey.
⁴ Department of Chemical Engineering, Faculty of Engineering, Pamukkale University, Denizli, Turkey.
⁵ Department of Nutrition and Dietetics, Faculty of Health Sciences, Hasan Kalyoncu University, Gaziantep, Turkey.
⁶ Department of Nutrition and Dietetics, Faculty of Health Sciences, Hasan Kalyoncu University, Gaziantep, Turkey. mlutfi.yola@hku.edu.tr.

Abstract

A sensitive and fast sandwich-type electrochemical SARS-CoV‑2 (COVID-19) nucleocapsid protein immunosensor was prepared based on bismuth tungstate/bismuth sulfide composite (Bi₂WO₆/Bi₂S₃) as electrode platform and graphitic carbon nitride sheet decorated with gold nanoparticles (Au NPs) and tungsten trioxide sphere composite (g-C₃N₄/Au/WO₃) as signal amplification. The electrostatic interactions between capture antibody and Bi₂WO₆/Bi₂S₃ led to immobilization of the capture nucleocapsid antibody. The detection antibody was then conjugated to g-C₃N₄/Au/WO₃ via the affinity of amino-gold. After physicochemically characterization via transmission electron microscopy (TEM), scanning electron microscopy (SEM), x-ray diffraction (XRD), and x-ray photoelectron spectroscopy (XPS), cyclic voltammetry (CV), differential pulse voltammetry (DPV), and electrochemical impedance spectroscopy (EIS) analysis were implemented to evaluate the electrochemical performance of the prepared immunosensor. The detection of SARS-CoV-2 nucleocapsid protein (SARS-CoV-2 NP) in a small saliva sample (100.0 µL) took just 30 min and yielded a detection limit (LOD) of 3.00 fg mL^-1, making it an effective tool for point-of-care COVID-19 testing.

Keywords: Bi2WO6/Bi2S3; COVID-19; Electrochemical impedance spectroscopy; Electrochemistry; Immunosensor; Voltammetry; g-C3N4/Au/WO3.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Biosensing Techniques
Electrochemical Techniques*
Gold
Metal Nanoparticles
SARS-CoV-2*

Substances

Gold