Amplifying visible signals in lateral flow assays using integrated nanoelectrokinetics

Area of Science:

• Biomedical Engineering
• Nanotechnology
• Diagnostic Assays

Background:

• Conventional lateral flow assays (LFAs) have limitations in sensitivity and detection limits.
• Improving point-of-care diagnostics is crucial, especially for infectious diseases like COVID-19.
• External instrumentation often complicates the use of advanced LFA technologies.

Purpose of the Study:

• To develop a novel lateral flow assay (LFA) enhanced by tangential nanoelectrokinetic force.
• To improve the limit of detection (LOD) and overall performance of LFAs without external equipment.
• To create a cost-effective and robust diagnostic tool for COVID-19 detection.

Main Methods:

• Integration of a Nafion-cellulose nanofibrils hybrid gel beneath the test line of the LFA.
• Utilizing the generated tangential nanoelectrokinetic force to enhance antigen-AuNP probe complex migration and accumulation.
• Testing the assay's performance using COVID-19 nucleocapsid protein and clinical samples.

Main Results:

• Achieved a 32.5-fold improvement in the limit of detection for COVID-19 nucleocapsid protein, reaching 0.24 ng/mL.
• Clinical trials demonstrated 100% sensitivity and 100% specificity.
• Exhibited high selectivity with no cross-reactivity against other common respiratory pathogens.

Conclusions:

• The nanoelectrokinetic force-enhanced LFA offers a significant performance improvement over conventional LFAs.
• This assay is a robust, cost-effective solution for point-of-care diagnostics, particularly in resource-limited settings.
• The technology holds promise for rapid and accurate detection of infectious diseases.