Single-Impact Electrochemistry in Paper-Based Microfluidics.
ACS Sens
; 7(3): 884-892, 2022 03 25.
Article
in English
| MEDLINE | ID: covidwho-1721394
ABSTRACT
Microfluidic paper-based analytical devices (µPADs) have experienced an unprecedented story of success. In particular, as of today, most people have likely come into contact with one of their two most famous examplesâthe pregnancy or the SARS-CoV-2 antigen test. However, their sensing performance is constrained by the optical readout of nanoparticle agglomeration, which typically allows only qualitative measurements. In contrast, single-impact electrochemistry offers the possibility to quantify species concentrations beyond the pM range by resolving collisions of individual species on a microelectrode. Within this work, we investigate the integration of stochastic sensing into a µPAD design by combining a wax-patterned microchannel with a microelectrode array to detect silver nanoparticles (AgNPs) by their oxidative dissolution. In doing so, we demonstrate the possibility to resolve individual nanoparticle collisions in a reference-on-chip configuration. To simulate a lateral flow architecture, we flush previously dried AgNPs along a microchannel toward the electrode array, where we are able to record nanoparticle impacts. Consequently, single-impact electrochemistry poses a promising candidate to extend the limits of lateral flow-based sensors beyond current applications toward a fast and reliable detection of very dilute species on site.
Keywords
Full text:
Available
Collection:
International databases
Database:
MEDLINE
Main subject:
Metal Nanoparticles
/
COVID-19
Type of study:
Experimental Studies
/
Qualitative research
Limits:
Female
/
Humans
/
Pregnancy
Language:
English
Journal:
ACS Sens
Year:
2022
Document Type:
Article
Affiliation country:
Acssensors.1c02703
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