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

Abstract

Currently, the global trend of several hundred thousand new confirmed COVID-19 patients per day has not abated significantly. Serological antibody detection has become an important tool for the self-screening of people. While the most commonly used colorimetric lateral flow immunoassay (LFIA) methods for the detection of COVID-19 antibodies are limited by low sensitivity and a lack of quantification ability. This leads to poor accuracy in the screening of early COVID-19 patients. Therefore, it is necessary to develop an accurate and sensitive autonomous antibody detection technique that will effectively reduce the COVID-19 infection rate. Here, we developed a three-line LFIA immunoassay based on polydopamine (PDA) nanoparticles for COVID-19 IgG and IgM antibodies detection to determine the degree of infection. The PDA-based three-line LFIA has a detection limit of 1.51 and 2.34 ng/mL for IgM and IgG, respectively. This assay reveals a good linearity for both IgM and IgG antibodies detection and is also able to achieve quantitative detection by measuring the optical density of test lines. In comparison, the commercial AuNP-based LFIA showed worse quantification results than the developed PDA-based LFIA for low-concentration COVID-19 antibody samples, making it difficult to distinguish between negative and positive samples. Therefore, the developed PDA-based three-line LFIA platform has the accurate quantitative capability and high sensitivity, which could be a powerful tool for the large-scale self-screening of people.

DNA aptamer-functionalized PDA nanoparticles: from colloidal chemistry to biosensor applications

“…The self-adhesive properties of PDA are used to attach nanomaterials onto the electrode’s surface and add chemical groups that can be utilized to immobilize recognizing species (e.g., antigens, antibodies, nucleic acids, aptamers, enzymes, or cells as receptors) for biosensor development ( Rocha et al, 2023 ). The surface modification of PDA NPs with COOH-PEG-Silane provides carboxyl groups for subsequent antibody conjugation ( Liu et al, 2023 ). The PDA NP-antibody complexes were used for colorimetric lateral flow immunoassay (LFIA) methods for the detection of COVID-19 ( Liu et al, 2023 ), Salmonella typhimurium ( Yang et al, 2023 ), and Zearalenone ( Xu et al, 2019 ).…”

“…The surface modification of PDA NPs with COOH-PEG-Silane provides carboxyl groups for subsequent antibody conjugation ( Liu et al, 2023 ). The PDA NP-antibody complexes were used for colorimetric lateral flow immunoassay (LFIA) methods for the detection of COVID-19 ( Liu et al, 2023 ), Salmonella typhimurium ( Yang et al, 2023 ), and Zearalenone ( Xu et al, 2019 ). PDA NPs can absorb spectrum covering the entire UV-visible and near-infrared range, making them extremely efficient fluorescence quenchers.…”