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Highly sensitive and ultra-rapid antigen-based detection of SARS-CoV-2 using nanomechanical sensor platform
Dilip Kumar Agarwal1, Vikas Nandwana1, Stephen E Henrich2
1Department of Material Science and Engineering and NUANCE Center, Northwestern University, Evanston, IL, 60208, USA.
Biosensors & Bioelectronics
|September 28, 2021
Summary
A new microcantilever sensor offers rapid, highly sensitive detection of SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus 2) antigenic proteins. This nanomechanical method provides precise results in under five minutes from patient swabs.
Area of Science:
- Nanotechnology
- Biosensing
- Medical Diagnostics
Background:
- The COVID-19 pandemic necessitates rapid and accurate diagnostic tools.
- Emerging SARS-CoV-2 variants require versatile detection methods.
- Existing diagnostic techniques may lack the speed or sensitivity needed for early screening.
Purpose of the Study:
- To develop a microcantilever-based optical sensor for rapid and sensitive detection of SARS-CoV-2.
- To utilize fluidic-atomic force microscopy (f-AFM) for nanomechanical deflection measurements.
- To demonstrate high specificity and sensitivity for SARS-CoV-2 antigenic proteins.
Main Methods:
- Antibodies against SARS-CoV-2 nucleocapsid (N) and spike (S1) receptor binding domain (RBD) proteins were immobilized on a gold-coated microcantilever.
- Antibody-antigen interactions were detected in real-time using f-AFM mediated nanomechanical deflection.
- The sensor was tested with purified proteins and nasopharyngeal swab specimens.
Main Results:
- The sensor detected SARS-CoV-2 N and S1 RBD proteins at concentrations as low as 1 ng/mL (33 pM).
- Detection from nasopharyngeal swabs yielded results in under 5 minutes.
- High specificity and analytical sensitivity were achieved, with a limit of detection (LoD) of 100 copies/mL (0.71 ng/mL) for N protein.
Conclusions:
- Nanomechanical signal transduction offers a promising approach for rapid SARS-CoV-2 antigen detection.
- The developed sensor demonstrates potential for early screening of SARS-CoV-2 and its variants.
- This technology could significantly aid in pandemic response and management.
