Electrochemical Capillary Driven Immunoassay for Detection of SARS-CoV-2
Kaylee M. Clark, Melissa S. Schenkel, Trey W. Pittman, Isabelle C. Samper, Loran B. R. Anderson, Wisarut Khamcharoen, Suad Elmegerhi, Rushika Perera, Weena Siangproh, Alan J. Kennan, Brian J. Geiss, David S. Dandy, Charles S. Henry
Abstract
The COVID-19 pandemic focused attention on a pressing need for fast, accurate, and low-cost diagnostic tests. This work presents an electrochemical capillary driven immunoassay (eCaDI) developed to detect SARS-CoV-2 nucleocapsid (N) protein. The low-cost flow device is made of polyethylene terephthalate (PET) and adhesive films. Upon addition of a sample, reagents and washes are sequentially delivered to an integrated screen-printed carbon electrode for detection, thus automating a full sandwich immunoassay with a single end-user step. The modified electrodes are sensitive and selective for SARS-CoV-2 N protein and stable for over 7 weeks. The eCaDI was tested with influenza A and Sindbis virus and proved to be selective. The eCaDI was also successfully applied to detect nine different SARS-CoV-2 variants, including Omicron.