Polydopamine Nanoparticles-Based Three-Line Lateral Flow Immunoassay for COVID-19 Detection.

Area of Science:

• Biomedical Engineering
• Nanotechnology
• Immunodiagnostics

Background:

• COVID-19 remains a significant global health concern, necessitating reliable self-screening tools.
• Current serological antibody detection methods, like colorimetric lateral flow immunoassays (LFIA), often lack sensitivity and quantification capabilities, impacting early diagnosis accuracy.
• There is a critical need for sensitive and accurate autonomous antibody detection techniques to mitigate COVID-19 spread.

Purpose of the Study:

• To develop a novel three-line LFIA utilizing polydopamine (PDA) nanoparticles for the sensitive and quantitative detection of COVID-19 IgG and IgM antibodies.
• To assess the performance of the PDA-based LFIA in terms of detection limits, linearity, and quantitative accuracy compared to traditional gold nanoparticle (AuNP)-based LFIAs.
• To establish an effective tool for large-scale self-screening and determining the degree of COVID-19 infection.

Main Methods:

• Development of a three-line lateral flow immunoassay (LFIA) incorporating polydopamine (PDA) nanoparticles.
• Utilized the PDA-based LFIA for the detection and quantification of COVID-19 specific IgM and IgG antibodies.
• Compared the quantitative performance of the PDA-based LFIA with a commercial gold nanoparticle (AuNP)-based LFIA using low-concentration antibody samples.

Main Results:

• The PDA-based three-line LFIA demonstrated low detection limits: 1.51 ng/mL for IgM and 2.34 ng/mL for IgG.
• The assay exhibited good linearity for both IgM and IgG detection, enabling quantitative measurements via optical density.
• The developed PDA-based LFIA provided superior quantification compared to AuNP-based LFIA, especially for low-concentration samples, improving differentiation between negative and positive results.

Conclusions:

• The developed polydopamine nanoparticle-based LFIA platform offers high sensitivity and accurate quantitative detection capabilities for COVID-19 antibodies.
• This advanced assay can overcome the limitations of traditional methods, providing a powerful tool for large-scale, accurate self-screening.
• The enhanced diagnostic performance holds potential for effective reduction of COVID-19 infection rates through improved early detection.