One-Step Rapid Quantification of Serum Neutralizing Antibody after COVID-19 Vaccination by a High-Throughput Nanoplasmonic Sensor Platform

The COVID-19 vaccination efficacy depends on serum production level of the neutralizing IgG antibody (NA) specific to the receptor binding domain of SARS-Cov-2 spike protein. Therefore, a high-throughput rapid assay to measure the total SARS-CoV-2 NA level is urgently needed for COVID-19 serodiagnosis, convalescent plasma therapy, vaccine development, and assessment. Here, we developed a nanoplasmonic immunosorbent assay (NanoPISA) platform for one-step rapid quantification of SARS-CoV-2 NAs in clinical serum samples for high-throughput evaluation of COVID-19 vaccine effectiveness. The NanoPISA platform enhanced by the use of nanoporous hollow gold nanoparticle coupling was able to detect SARS-CoV-2 NAs with a limit of detection of 0.1 ng/mL within 15 min. The one-step NanoPISA for SARS-CoV-2 NA detection in clinical specimens yielded good results, comparable to those obtained in the gold standard seroneutralization test and the surrogate virus neutralizing ELISA. Collectively, our findings indicate that the one-step NanoPISA may offer a rapid and high-throughput NA quantification platform for evaluating the effectiveness of COVID-19 vaccines.