# Indium Tin Oxide-Based Voltammetric Biosensor for the Detection of Antibodies Against the SARS-CoV-2 Virus Spike Protein

## TL;DR

This paper introduces a new biosensor using indium tin oxide to detect antibodies against the SARS-CoV-2 virus spike protein in serum samples.

## Contribution

The novel biosensor uses recombinant spike glycoprotein immobilized on an ITO electrode modified with APTES for antibody detection.

## Key findings

- The biosensor shows a linear relationship between current density and anti-rS concentration.
- The limit of detection was 113 ng/mL (0.75 nM), and the limit of quantitation was 338 ng/mL (2.25 nM).
- The biosensor efficiently evaluates immune status without requiring a redox probe.

## Abstract

This study aims to propose a plausible application of a novel electrochemical biosensing system for detecting antibodies against SARS-CoV-2 (anti-rS) in serum samples. The uniqueness of this study lies in the biosensor utilizing recombinant spike glycoprotein (SCoV2-rS) immobilized on an indium tin oxide (ITO) electrode modified with (3-aminopropyl)triethoxysilane (APTES). The electrochemical performance was evaluated using square wave voltammetry (SWV), demonstrating a linear relationship between the current density and anti-rS concentration. The limit of detection (LOD) was found to be 113 ng/mL (0.75 nM), and the limit of quantitation (LOQ) was equal to 338 ng/mL (2.25 nM). The reported electrochemical biosensor offers a straightforward and efficient method for evaluating the immune status of individuals who have recovered from COVID-19 and been vaccinated against this virus without the need for any redox probe.