Determination of rSpike Protein by Specific Antibodies with Screen-Printed Carbon Electrode Modified by Electrodeposited Gold Nanostructures
Journal
Biosensors
Journal Volume
12
Journal Issue
8
Date Issued
2022-08-03
Author(s)
Drobysh, Maryia
Liustrovaite, Viktorija
Baradoke, Ausra
Viter, Roman
Ramanavicius, Arunas
Ramanaviciene, Almira
Abstract
In this research, we assessed the applicability of electrochemical sensing techniques for detecting specific antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike proteins in the blood serum of patient samples following coronavirus disease 2019 (COVID-19). Herein, screen-printed carbon electrodes (SPCE) with electrodeposited gold nanostructures (AuNS) were modified with L-Cysteine for further covalent immobilization of recombinant SARS-CoV-2 spike proteins (rSpike). The affinity interactions of the rSpike protein with specific antibodies against this protein (anti-rSpike) were assessed using cyclic voltammetry (CV) and differential pulse voltammetry (DPV) methods. It was revealed that the SPCE electroactive surface area increased from 1.49 ± 0.02 cm2 to 1.82 ± 0.01 cm2 when AuNS were electrodeposited, and the value of the heterogeneous electron transfer rate constant (k0) changed from 6.30 × 10-5 to 14.56 × 10-5. The performance of the developed electrochemical immunosensor was evaluated by calculating the limit of detection and limit of quantification, giving values of 0.27 nM and 0.81 nM for CV and 0.14 nM and 0.42 nM for DPV. Furthermore, a specificity test was performed with a solution of antibodies against bovine serum albumin as the control aliquot, which was used to assess nonspecific binding, and this evaluation revealed that the developed rSpike-based sensor exhibits low nonspecific binding towards anti-rSpike antibodies.
Subjects
COVID-19; SARS-CoV-2 virus; antigen–antibody complex; cyclic voltammetry (CV); differential pulse voltammetry (DPV); electrochemical immunosensor; electrochemical impedance spectroscopy (EIS); gold nanostructures (AuNS); self-assembled monolayer (SAM); spike protein (Spike)
Publisher
MDPI
Type
journal article