Work

Sensitive and rapid detection of SARS-CoV-2 N-protein using laser wave-mixing spectroscopy coupled with capillary electrophoresis

Year: 2025

Type: article

Abstract: To develop a sensitive method for detecting SARS-CoV-2 nucleocapsid protein (N-protein), using a compact, rapid, and cost-effective laser wave-mixing spectroscopy platform coupled with capillary electrophoresis. We employed nonlinear laser wave-mixing spectroscopy, an absorption-based technique, to detect Chromeo P540-labeled SARS-CoV-2 N-protein. A 532 nm solid-state laser was used as the excitation source. The method was integrated with capillary zone electrophoresis for enhanced separation and sensitivity. Field-amplified sample stacking was implemented to preconcentrate analytes, and electropherograms were collected using a photodetector and lock-in amplifier system. The method achieved a concentration detection limit of 0.26 nM or 11 ng/mL, corresponding to approximately 19 zeptomoles of analyte present within the 75 pL optical probe volume. Capillary electrophoresis allowed detection and separation of both SARS-CoV-2 N-protein and BSA within 2 minutes. Optimal labeling with a 1:5 protein-to-dye ratio maximized signal without excess background. This study demonstrates a sensitive, and portable diagnostic platform for SARS-CoV-2 detection. The laser wave-mixing system provides high sensitivity, rapid response, and low-cost operation, supporting its potential as a molecular detection tool in low-resource or field settings.

Source: Next research.

DOI: 10.1016/j.nexres.2025.101273

Authors: Nino Shatirishvili, William G. Tong

Institution: San Diego State University

Language: English

Topic: Microfluidic and Capillary Electrophoresis Applications

Subfield: Biomedical Engineering

Field: Engineering

Domain: Physical Sciences

SDG: Good health and well-being

Open Access status: hybrid

Estimated APC paid: $2,500