Related Experiment Video
Updated: Sep 21, 2025
A Rapid, Multiplex Dual Reporter IgG and IgM SARS-CoV-2 Neutralization Assay for a Multiplexed Bead-Based Flow Analysis System
Published on: April 6, 2021
Rapid Detection of Anti-SARS-CoV-2 Antibodies with a Screen-Printed Electrode Modified with a Spike Glycoprotein
Wilson A Ameku1,2, David W Provance1,2, Carlos M Morel1
1Oswaldo Cruz Foundation (FIOCRUZ), Center for Technological Development in Health (CDTS)/National Institute of Science and Technology for Innovation in Neglected Populations Diseases (INCT-IDPN), Rio de Janeiro 21040-900, RJ, Brazil.
Insights
A new electrochemical biosensor offers rapid, affordable detection of COVID-19 by identifying antibodies against the SARS-CoV-2 spike protein. This diagnostic tool shows high accuracy and potential for detecting new variants.
Area of Science:
- Biomedical Engineering
- Immunology
- Infectious Disease Diagnostics
Background:
- The COVID-19 pandemic, caused by SARS-CoV-2, necessitates rapid, low-cost diagnostic methods.
- Existing diagnostic approaches require improvement in speed, cost-effectiveness, and ease of use.
- There is a critical need for accessible tools to confirm SARS-CoV-2 infection.
Purpose of the Study:
- To develop an affordable electrochemical biosensor for rapid detection of SARS-CoV-2 specific IgG antibodies.
- To utilize a specific B-cell epitope of the SARS-CoV-2 spike protein as the target molecule.
- To create a user-friendly diagnostic tool for COVID-19.
Main Methods:
- A linear B-cell epitope (EP) of the SARS-CoV-2 spike glycoprotein was synthesized and immobilized on a screen-printed electrode (SPE).
- The biosensor detects SARS-CoV-2 specific IgG antibodies by measuring the formation of an immunocomplex via square-wave voltammetry.
- Hydroquinone (HQ) generation was used as the electrochemical signal for antibody detection.
Main Results:
- The EP-based biosensor demonstrated high selectivity (93%) and specificity (100%) for COVID-19.
- No cross-reactivity was observed with antibodies against other diseases, including Dengue and Chikungunya.
- The biosensor effectively differentiated infected from non-infected individuals even with small sample volumes.
Conclusions:
- The developed electrochemical biosensor is suitable for diagnosing COVID-19 using serum samples.
- Results showed good agreement with established molecular biology diagnostic methods.
- The technology's adaptability allows for potential diagnosis of new SARS-CoV-2 variants and other pathogens.
Background:
The coronavirus disease of 2019 (COVID-19) is caused by an infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). It was recognized in late 2019 and has since spread worldwide, leading to a pandemic with unprecedented health and financial consequences. There remains an enormous demand for new diagnostic methods that can deliver fast, low-cost, and easy-to-use confirmation of a SARS-CoV-2 infection. We have developed an affordable electrochemical biosensor for the rapid detection of serological immunoglobulin G (IgG) antibody in sera against the spike protein.
Materials And Methods:
A previously identified linear B-cell epitope (EP) specific to the SARS-CoV-2 spike glycoprotein and recognized by IgG in patient sera was selected for the target molecule. After synthesis, the EP was immobilized onto the surface of the working electrode of a commercially available screen-printed electrode (SPE). The capture of SARS-CoV-2-specific IgGs allowed the formation of an immunocomplex that was measured by square-wave voltammetry from its generation of hydroquinone (HQ).
Results:
An evaluation of the performance of the EP-based biosensor presented a selectivity and specificity for COVID-19 of 93% and 100%, respectively. No cross-reaction was observed to antibodies against other diseases that included Chagas disease, Chikungunya, Leishmaniosis, and Dengue. Differentiation of infected and non-infected individuals was possible even at a high dilution factor that decreased the required sample volumes to a few microliters.
Conclusion:
The final device proved suitable for diagnosing COVID-19 by assaying actual serum samples, and the results displayed good agreement with the molecular biology diagnoses. The flexibility to conjugate other EPs to SPEs suggests that this technology could be rapidly adapted to diagnose new variants of SARS-CoV-2 or other pathogens.
