A label-free nanowell-based impedance sensor for ten-minute SARS-CoV-2 detection.

Area of Science:

• Biomedical Engineering
• Nanotechnology
• Biosensing

Background:

• Label-free biosensing preserves native biomolecular conformation and activity.
• Point-of-care diagnostics are crucial for rapid disease detection.
• Existing methods for SARS-CoV-2 detection can be time-consuming.

Purpose of the Study:

• To develop and validate a novel electronic biosensing platform for SARS-CoV-2 detection.
• To utilize micro-fabricated nanowell-based impedance sensors for rapid diagnosis.
• To ensure preservation of native conformation and biological activity of target biomolecules.

Main Methods:

• Fabrication of a micro-structured silica substrate with a 5 × 5 nanowell array.
• Functionalization of the nanowell array with specific antibodies.
• Real-time impedance monitoring for detecting SARS-CoV-2 spike proteins in various buffers.
• Assays performed using phosphate-buffered saline (PBS) and artificial saliva.

Main Results:

• Rapid diagnostic results obtained within ten minutes using small sample volumes (<5 μL).
• Achieved a detection limit of 0.2 ng mL⁻¹ (1.5 pM) for SARS-CoV-2 spike proteins.
• Demonstrated specificity by differentiating between SARS-CoV-2 and MERS-CoV spike proteins.

Conclusions:

• The developed nanowell impedance biosensor offers a promising solution for rapid, label-free, point-of-care SARS-CoV-2 detection.
• The platform maintains the integrity of biomolecular samples.
• High sensitivity and specificity indicate potential for clinical application.