Cost-Effective Modular Biosensor for SARS-CoV-2 and Influenza A Detection.

Area of Science:

• Nanotechnology and Biosensing
• Molecular Diagnostics
• Virology

Background:

• Accurate and rapid detection of viral pathogens like SARS-CoV-2 and Influenza A is crucial for public health.
• Existing diagnostic methods can be time-consuming, expensive, or lack multiplexing capabilities.
• Electrochemical biosensors offer a promising platform for sensitive and cost-effective molecular detection.

Purpose of the Study:

• To develop a modular, reusable, and cost-effective electrochemical biosensor for detecting specific viral nucleic acid sequences.
• To enable simultaneous detection of SARS-CoV-2 (genes S and N) and Influenza A virus (gene M) using a single platform.
• To demonstrate the biosensor's potential for multiplexed detection of current and future pathogens.

Main Methods:

• Fabrication of a five-stranded four-way junction (5S-4WJ) DNA structure immobilized on an electrode.
• Utilized a universal stem-loop (USL) strand, two auxiliary DNA strands (m and f) for target specificity, and a methylene blue redox strand (UMeB).
• Employed square wave voltammetry (SWV) for sequence-specific detection and assessed electrode reusability through a simple rinsing and re-hybridization procedure.

Main Results:

• The 5S-4WJ biosensor demonstrated selective detection of target viral genes (SARS-CoV-2 S/N, Influenza A M).
• The biosensor maintained high signal integrity after multiple reuse cycles, indicating excellent electrode stability.
• Achieved a low limit of quantification (LOQ) as low as 17 pM, highlighting high sensitivity.

Conclusions:

• The developed 5S-4WJ electrochemical biosensor is a versatile, cost-effective, and reusable platform for multiplex viral pathogen detection.
• Its modular design and reusability make it suitable for adaptable diagnostic assays targeting various pathogens.
• This technology holds significant potential for rapid, sensitive, and sustainable infectious disease surveillance.