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Gravity-Driven Microfluidic Siphons: Fluidic Characterization and Application to Quantitative Immunoassays
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Metadata
Document Title
Gravity-Driven Microfluidic Siphons: Fluidic Characterization and Application to Quantitative Immunoassays
Author
Reis NM, Needs SH, Jegouic SM, Gill KK, Sirivisoot S, Howard S, Kempe J, Bola S, Al-Hakeem K, Jones IM, Prommool T, Luangaram P, Avirutnan P, Puttikhunt C, Edwards AD
Name from Authors Collection
Scopus Author ID
57218341452
Affiliations
University of Reading; University of Reading; University of Bath; University of Bath; Mahidol University; National Science & Technology Development Agency - Thailand; National Center Genetic Engineering & Biotechnology (BIOTEC); Mahidol University
Type
Article
Source Title
ACS SENSORS
Year
2021
Volume
6
Issue
12
Page
4338-4348
Open Access
hybrid, Green Accepted, Green Published
Publisher
AMER CHEMICAL SOC
DOI
10.1021/acssensors.1c01524
Format
Abstract
A range of biosensing techniques including immunoassays are routinely used for quantitation of analytes in biological samples and available in a range of formats, from centralized lab testing (e.g., microplate enzyme-linked immunosorbent assay (ELISA)) to automated point-of-care (POC) and lateral flow immunochromatographic tests. High analytical performance is intrinsically linked to the use of a sequence of reagent and washing steps, yet this is extremely challenging to deliver at the POC without a high level of fluidic control involving, e.g., automation, fluidic pumping, or manual fluid handling/pipetting. Here we introduce a microfluidic siphon concept that conceptualizes a multistep dipstick for quantitative, enzymatically amplified immunoassays using a strip of microporous or microbored material. We demonstrated that gravity-driven siphon flow can be realized in single-bore glass capillaries, a multibored microcapillary film, and a glass fiber porous membrane. In contrast to other POC devices proposed to date, the operation of the siphon is only dependent on the hydrostatic liquid pressure (gravity) and not capillary forces, and the unique stepwise approach to the delivery of the sample and immunoassay reagents results in zero dead volume in the device, no reagent overlap or carryover, and full start/stop fluid control. We demonstrated applications of a 10-bore microfluidic siphon as a portable ELISA system without compromised quantitative capabilities in two global diagnostic applications: (1) a four-plex sandwich ELISA for rapid smartphone dengue serotype identification by serotype-specific dengue virus NS1 antigen detection, relevant for acute dengue fever diagnosis, and (2) quantitation of anti-SARS-CoV-2 IgG and IgM titers in spiked serum samples. Diagnostic siphons provide the opportunity for high-performance immunoassay testing outside sophisticated laboratories, meeting the rapidly changing global clinical and public health needs.
Keyword
Biosensor | dengue NS1 | immunoassays | microfluidic | porous membrane | portable ELISA | siphon | smartphone diagnostics
Industrial Classification
Knowledge Taxonomy Level 1
Knowledge Taxonomy Level 2
Knowledge Taxonomy Level 3
Funding Sponsor
EPSRC; University of Bath; Wellcome Trust [204388/Z/16/Z]; Newton Fund Institutional Links award [IL35237556]; EPSRC [EP/R022410/1]; Defence and Security Accelerator [ACC6010011]
License
CC-BY
Rights
Authors
Publication Source
WOS