Improving immunoassay detection accuracy of anti-SARS-CoV-2 antibodies through dual modality validation

Yuhao Ma; Daniel To; Jie Zeng; Lian C T Shoute; Meng Wu; Shawn Babiuk; Ran Zhuo; Carmen Charlton; Jamil N Kanji; Lorne Babiuk; Jie Chen

doi:10.1016/j.biosx.2022.100176

Improving immunoassay detection accuracy of anti-SARS-CoV-2 antibodies through dual modality validation

Biosens Bioelectron X. 2022 Sep:11:100176. doi: 10.1016/j.biosx.2022.100176. Epub 2022 Jun 5.

Authors

Yuhao Ma¹, Daniel To¹, Jie Zeng¹, Lian C T Shoute¹, Meng Wu², Shawn Babiuk^{3

4}, Ran Zhuo⁵, Carmen Charlton^{6

5

7}, Jamil N Kanji^{6

5

8

9}, Lorne Babiuk¹⁰, Jie Chen^{1

11}

Affiliations

¹ Department of Electrical and Computer Engineering, University of Alberta, Edmonton, AB, T6G 2V4, Canada.
² Department of Chemical and Materials Engineering, University of Alberta, Edmonton, AB, T6G 2R3, Canada.
³ National Centre for Foreign Animal Disease, Canadian Food Inspection Agency, Winnipeg, MB, Canada.
⁴ Department of Immunology, University of Manitoba, Winnipeg, MB, Canada.
⁵ Public Health Laboratory, Alberta Precision Laboratories, Calgary, AB, Canada.
⁶ Department of Laboratory Medicine and Pathology, University of Alberta, Edmonton, AB, T6G 2B7, Canada.
⁷ Li Ka Shing Institute for Virology, University of Alberta, Edmonton, AB, Canada.
⁸ Division of Infectious Diseases, Department of Medicine, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.
⁹ Department of Pathology & Laboratory Medicine, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.
¹⁰ Vaccine and Infectious Disease Organization, University of Alberta, Edmonton, AB, Canada.
¹¹ Department of Biomedical Engineering, University of Alberta, Edmonton, AB T6G 2V2, Canada.

Abstract

A novel test strategy is proposed with dual-modality detection techniques for COVID-19 antibody detection. The full-length S protein of SARS-CoV-2 was chemically immobilized on a glass surface to capture anti-SARS-CoV-2 IgG in patient serum and was detected through either Electrochemical Impedance Spectroscopy (EIS) or fluorescence imaging with labeled secondary antibodies. Gold nanoparticles conjugated with protein G were used as the probe and the bound GNP-G was detected through EIS measurements. Anti-human-IgG conjugated with the fluorescent tag Alexa Fluor 488 was used as the probe for fluorescence imaging. Clinical SARS-CoV-2 IgG positive serum and negative controls were used to validate both modalities. For fluorescence-based detection, a high sensitivity was noticed with a quantification range of 0.01-0.1 A.U.C. and a LOD of 0.004 A.U.C. This study demonstrates the possibility of utilizing different measurement techniques in conjunction for improved COVID-19 serology testing.

Keywords: Anti-SARS-CoV-2 IgG; COVID-19; Electrochemical impedance spectroscopy (EIS); Fluorescence labeling; Serology testing.