Electronic Immunoassay Using Enzymatic Metallization on Microparticles.
Josiah Rudge1, Madeline Hoyle1, Neda Rafat1
1Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States.
ACS Omega
|July 3, 2023
Summary
We developed a low-cost electronic method for immunoassays using silver metallization and electrical impedance. This technique allows sensitive detection of analyte binding without optical instruments, demonstrated for COVID-19 antibody detection.
Area of Science:
- Biotechnology
- Biosensing
- Analytical Chemistry
Background:
- Bead-based immunoassays typically require complex optical detection systems.
- Developing direct electronic readouts for immunoassays is crucial for cost-effective diagnostics.
Purpose of the Study:
- To present an inexpensive, direct electronic readout method for bead-based immunoassays.
- To enable sensitive detection of analyte binding without optical instrumentation.
Main Methods:
- Analyte binding is converted to enzymatically amplified silver metallization on microparticles.
- Microparticles are analyzed using a microfluidic impedance spectrometry system with a 3D-printed microaperture.
- Single-bead multifrequency electrical impedance spectra are captured and analyzed with a machine learning algorithm.
Main Results:
- Metallized microparticles exhibit unique impedance signatures.
- The method provides a direct electronic readout of silver metallization density.
- The scheme successfully measured antibody response to viral nucleocapsid protein in COVID-19 patient serum.
Conclusions:
- This novel method offers a sensitive and inexpensive electronic detection platform for immunoassays.
- The system eliminates the need for optical components, simplifying assay instrumentation.
- The technology shows promise for rapid and accessible diagnostics, including infectious disease monitoring.
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