Indiscriminate SARS-CoV-2 multivariant detection using magnetic nanoparticle-based electrochemical immunosensing

Area of Science:

• Biomedical Engineering
• Infectious Disease Diagnostics
• Biosensor Technology

Background:

• The emergence of SARS-CoV-2 variants poses challenges for accurate diagnosis and pandemic control.
• Developing sensitive and specific diagnostic methods is crucial for managing the ongoing pandemic.
• Existing diagnostic methods may struggle with the increasing mutation frequency and diverse variants of SARS-CoV-2.

Purpose of the Study:

• To develop and evaluate an electrochemical immunosensor for detecting SARS-CoV-2 and its variants.
• To compare the efficacy of a SARS-CoV-2 antibody cocktail with monoclonal antibodies for virus detection.
• To assess the sensor's performance in terms of sensitivity, specificity, and accuracy using clinical samples.

Main Methods:

• Fabrication of an electrochemical immunosensor utilizing magnetic nanoparticles conjugated with a SARS-CoV-2 antibody cocktail.
• Comparison of the antibody cocktail with commercially available anti-SARS-CoV-2 S1 and anti-S2 monoclonal antibodies.
• Testing the sensor's performance using human nasopharyngeal swab samples pre-diagnosed via RT-PCR, including various SARS-CoV-2 variants.

Main Results:

• The antibody cocktail-based immunosensor demonstrated a lower limit of detection (0.53-0.75 ng/mL) compared to monoclonal antibody platforms (0.93-0.99 ng/mL).
• The developed sensor achieved 100% overall sensitivity, specificity, and accuracy across all tested samples, including original, alpha, beta, and delta variants.
• The antibody cocktail showed superior performance in detecting a wider range of SARS-CoV-2 variants compared to monoclonal antibodies.

Conclusions:

• A versatile electrochemical biosensor using a polyclonal antibody cocktail enables indiscriminate detection of diverse SARS-CoV-2 variants.
• This diagnostic approach offers high sensitivity, specificity, and accuracy, outperforming current monoclonal antibody-based methods.
• The developed immunosensor presents a valuable and efficient tool for combating the evolving SARS-CoV-2 pandemic.