The efficacy of coronavirus disease 2019 (COVID-19) vaccination is closely related to the serum levels of SARS-CoV-2-neutralizing antibodies (NAb) that bind to the receptor-binding domain (RBD) of the SARS-CoV-2 spike protein. Therefore, the rapid and quantitative measurement of SARS-CoV-2 NAb in the sera of vaccinated individuals is essential to develop an effective vaccine and further achieve population immunity, that is, herd immunity. The plaque reduction neutralization test, the gold standard for NAb effectiveness in serological tests, is accurate but requires biosafety level 3 facilities because of the use of the virus, which hampers its application in common laboratories and clinical practice. Here, we developed a bioresponsive nanogel-based surface plasmon resonance (nSPR) platform that detects SARS-CoV-2 NAb in clinical samples without complicated pretreatment. We found that multivalent protein binding (MPB) between the nanogel-conjugated RBD protein and SARS-CoV-2 NAb yields significantly enhanced SPR signals compared to the nonspecific interference from serum proteins in the nSPR assay. The excellence of our nanogel-based SARS-CoV-2 NAb test is due to its selectivity for NAb, with resistance to all other proteins, allowing the rapid detection and quantification of NAbs in each individual. Importantly, this nSPR assay provides a NAb detection platform for easier and safer COVID-19 vaccination strategies.
Bibliographical noteFunding Information:
J.K. acknowledges the financial support from the National Research Foundation of Korea (NRF-2022R1I1A1A01064249) and the Korea Health Technology R&D Project through the Korea Health Industry Development Institute (KHIDI), funded by the Ministry of Health & Welfare (HR14C0007 and HV20C0054). This research was also supported by a grant from the Korea Health Technology R&D Project through the Korea Health Industry Development Institute (KHIDI) and Korea Infectious Diseases Clinical Trials Initiative, funded by the Ministry of Health & Welfare, Republic of Korea (grant number: HE21C0001).
© 2023 American Chemical Society.
- neutralizing antibody
- surface plasmon resonance (SPR)
ASJC Scopus subject areas
- Process Chemistry and Technology
- Polymers and Plastics
- Organic Chemistry