A particle-based microfluidic fluorescent lateral flow assay for rapid and sensitive detection of SARS-CoV-2 antibody

• Published in: Sensors and actuators. B, Chemical Chemical, 2023-11, Vol.394, p.134381, Article 134381
• Main Authors: Kim, Juyeong, Lee, Sanghyun, Kim, Hojin
• Format: Article
• Language: English
• Subjects: Lateral flow immunoassay; Microfluidics; Microparticle; Rapid diagnostic test; SARS-CoV-2 antibody
• ISSN: 0925-4005; 1873-3077
• DOI: 10.1016/j.snb.2023.134381

Prompt isolation and treatment of patients are effective measures for preventing the spread of infectious diseases. Therefore, a sensitive and early diagnostic test is crucial for controlling pandemics. Herein, we present a tubeless integrated microfluidic lateral flow immunoassay chip for rapid and sensitive detection of SARS-CoV-2 antibodies. Fully automated chip operation is demonstrated by incorporating a dry reagent storage chamber, staggered herringbone micromixer, mobile particle-based detection zone, and spontaneous liquid transportation mechanism. The effects of the position and number of dry reagent patterns on assay time and detection sensitivity were investigated. Under laminar flow conditions, a staggered herringbone mixer was used to achieve rapid and complete mixing of the sample and reagent. In addition, we found that the volumetric flux of the sample and reagent complex over the surface of the particles is a crucial factor for improving detection sensitivity. The limit of detection of an anti-SARS-CoV-2 spike protein monoclonal antibody was determined to be 10.35 ng/mL in assay buffer with a total assay time of 15 min. In the analyte concentration range of 15.625–1000 ng/mL, the linearity and spike-recovery of the assay on serially diluted serum samples were excellent (R2 ≈ 0.99 and recovery rate of 82.9–112 %). The integrated microfluidic immunoassay chip demonstrates rapid and simple operation, which is promising for the diagnosis and monitoring of SARS-CoV-2 antibodies. •A vacuum-driven microfluidic chip ensures reliable operation without air bubbles.•The dissolving rate of dry reagent influences assay time and detection sensitivity.•The volumetric flux is a critical parameter for improving detection sensitivity.