ELECTRONIC IMMUNOASSAY USING ENZYMATIC METALLIZATION ON MICROPARTICLES

ABSTRACT

We present here a bead-based immunoassay which provides a sensitive direct electronic readout without the use of any intermediate optics. Analyte binding to antigen-coated microparticles is converted to probe-directed enzymatically amplified silver metallization on microparticle surfaces. The microparticles are then characterized in a high-throughput manner via electrical impedance spectra captured as they flow through a 3-D printed plastic micro-aperture. Metallized microparticles are found to have unique impedance signatures. This enables an electronic readout of the silver metallization density on microparticle surfaces and hence analyte concentration as well. Here we use this scheme to measure the antibody response to the viral nucleocapsid protein in convalescent COVID-19 patient serum. © 2021 MicroTAS 2021 - 25th International Conference on Miniaturized Systems for Chemistry and Life Sciences. All rights reserved.