Biosensors and Bioelectronics: X (Sep 2022)

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

Journal volume & issue
Vol. 11
p. 100176

Abstract

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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.

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