Handheld Microfluidic Filtration Platform Enables Rapid, Low‐Cost, and Robust Self‐Testing of SARS‐CoV‐2 Virus. Issue 52 (30th November 2021)

• Record Type: Journal Article
• Authors: Xu, Jiang; Suo, Wenhao; Goulev, Youlian; Sun, Lei; Kerr, Liam; Paulsson, Johan; Zhang, Yan; Lao, Taotao
• Is Part Of: Small. Volume 17:Issue 52(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-11-30
• Subjects: biomedical engineering -- COVID‐19 diagnostics -- microassays -- microfluidics -- point of care; Nanotechnology -- Periodicals; Nanoparticles -- Periodicals; Microtechnology -- Periodicals; 620.5
• DOI: 10.1002/smll.202104009
• Languages: English
• ISSNs: 1613-6810

Abstract

Abstract: Here, a novel microfluidic test kit combining ultrahigh throughput hydrodynamic filtration and sandwich immunoassay is reported. Specifically, nano and microbeads coated with two different, noncompetitive antibodies, are used to capture the severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) nucleocapsid (N) proteins simultaneously, forming larger complexes. Microfluidic filtration discards free nanobeads but retains antigen‐bridged complexes in the observation zone, where a display of red color indicates the presence of antigen in the sample. This testing platform exhibits high throughput separation (<30 s) and enrichment of antigen that exceeds the traditional lateral flow assays or microfluidic assays, with a low limit of detection (LoD) < 100 copies mL ‐1 . In two rounds of clinical trials conducted in December 2020 and August 2021, the assays demonstrate high sensitivities of 95.4% and 100%, respectively, which proves this microfluidic test kit is capable of detecting SARS‐CoV‐2 virus variants evolved over significant periods of time. Furthermore, the mass‐produced chip can be fabricated at a cost of $0.98/test and the robust design allows the chip to be reused for over 50 times. All of these features make the microfluidic test kit particularly suitable for areas with inadequate medical infrastructure and a shortage of laboratory resources. Abstract : The microfluidic diagnostic platform combining sandwich immunoassay and hydrodynamic filtration described here enables rapid detection of severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2). The nano‐ and micro‐ beads are coated with antibodies targeting nucleocapsid proteins. Microfluidic filtration discards free nanobeads but retains antigen‐bridged complexes in the observation zone, where a display of red/white color indicates the positive/negative result.