Detection of the SARS-CoV-2 humanized antibody with paper-based ELISA

Analyst. 2020 Nov 23;145(23):7680-7686. doi: 10.1039/d0an01609h.

Abstract

This work reports the development of a rapid, simple and inexpensive colorimetric paper-based assay for the detection of the severe acute respiratory symptom coronavirus 2 (SARS-CoV-2) humanized antibody. The paper device was prepared with lamination for easy sample handling and coated with the recombinant SARS-CoV-2 nucleocapsid antigen. This assay employed a colorimetric reaction, which is followed by horseradish peroxidase (HRP) conjugated detecting antibody in the presence of the 3,3',5,5'-tetramethylbenzidine (TMB) substrate. The colorimetric readout was evaluated and quantified for specificity and sensitivity. The characterization of this assay includes determining the linear regression curve, the limit of detection (LOD), the repeatability, and testing complex biological samples. We found that the LOD of the assay was 9.00 ng μL-1 (0.112 IU mL-1). The relative standard deviation was approximately 10% for a sample number of n = 3. We believe that our proof-of-concept assay has the potential to be developed for clinical screening of the SARS-CoV-2 humanized antibody as a tool to confirm infected active cases or to confirm SARS-CoV-2 immune cases during the process of vaccine development.

MeSH terms

  • Antibodies, Monoclonal, Humanized / blood*
  • Antibodies, Monoclonal, Humanized / immunology
  • Antibodies, Viral / blood*
  • Antibodies, Viral / immunology
  • Armoracia / enzymology
  • Benzidines / chemistry
  • COVID-19 / diagnosis
  • COVID-19 Testing / instrumentation
  • COVID-19 Testing / methods*
  • Colorimetry / instrumentation
  • Colorimetry / methods*
  • Coronavirus Nucleocapsid Proteins / immunology
  • Enzyme-Linked Immunosorbent Assay / instrumentation
  • Enzyme-Linked Immunosorbent Assay / methods*
  • Horseradish Peroxidase / chemistry
  • Humans
  • Limit of Detection
  • Paper*
  • Phosphoproteins / immunology
  • Proof of Concept Study
  • SARS-CoV-2 / chemistry
  • SARS-CoV-2 / immunology*

Substances

  • Antibodies, Monoclonal, Humanized
  • Antibodies, Viral
  • Benzidines
  • Coronavirus Nucleocapsid Proteins
  • Phosphoproteins
  • nucleocapsid phosphoprotein, SARS-CoV-2
  • 3,3',5,5'-tetramethylbenzidine
  • Horseradish Peroxidase