Rapid biosensing SARS-CoV-2 antibodies in vaccinated healthy donors

Abstract

In this study, we report two optical fiber-biolayer interferometry (FO-BLI)-based biosensors for the rapid detection of SARS-CoV-2 neutralizing antibodies (NAbs) and binding antibodies (BAbs) in human serum. The use of signal enhancer 3,3′-diaminobenzidine enabled the detection of NAbs, anti-receptor binding domain (anti-RBD) BAbs, and anti-extracellular domain of spike protein (anti-S-ECD) BAbs up to as low as 10 ng/mL in both buffer and 100-fold diluted serum. NAbs and BAbs could be detected individually over 7.5 and 13 min, respectively, or simultaneously by prolonging the detection time of the former. The protocol for the detection of BAbs could be utilized for detection of the RBD-N501Y variant with equal sensitivity and speed. Results of the NAbs and the anti-RBD BAbs biosensors correlated well with those of the corresponding commercial assay kit. Clinical utility of the two FO-BLI biosensors were further validated using a small cohort of samples randomly taken from 16 enrolled healthy participants who received inactivated vaccines. Two potent serum antibodies were identified, which showed high neutralizing capacities toward RBD and pseudovirus. Overall, the rapid automated biosensors can be used for an individual sample measurement of NAbs and BAbs as well as for high-throughput analysis. The findings of this study would be useful in COVID-19 related studies in vaccine trials, research on dynamics of the immune response, and epidemiology studies.

Rapid Optical Biosensing of SARS-CoV-2 Spike Proteins in Artificial Samples

“…Our latest research in monitoring SARS-CoV-2 antibodies and small molecule drugs proved that the combination of HRP with the metal precipitate DAB was sufficient in enhancing the optical signals [ 13 , 14 ]. Similar to those two works, a dilution factor of 200-fold for DAB was also proved to be appropriate for SARS-CoV-2 ECD detection with a limited background interference and sufficient positive signal when ECD is at a concentration of 1.15 nM.…”

“…In this work, we used a fiber-optic biolayer interferometry (FO-BLI)-based biosensor for on-site and automated detection of SARS-CoV-2 within 13 min. The FO-BLI detection system was described in detail in our two recent papers [ 13 , 14 ]. When vertical light enters, the reflected light from the 1st and 2nd interface of sensors forms an interference curve.…”

Advances in Biosensing Technologies for Diagnosis of COVID-19

“…This sensor is robust and doesn’t need sensor surface blocking to prevent the nonspecific adsorption of biomolecules from the serum. The main advantage of these dip-in sensors is that they are easy to handle and routine use for the assay [ 79 ]. Anti-SARS-CoV-2 antibody levels have been detected using Janus emulsions or Janus particles as biosensors.…”

Nanoplasmonic multiplex biosensing for COVID-19 vaccines

“…Unfortunately the emerging virus variants make the pandemic situation very challenging ( Koyama et al, 2020 ). The profiling of specificity and quantity of the serum antibody is highly informative and has served pivotal roles in developing individualized diagnostics and therapeutics strategies ( Amanat et al, 2020 ; Bai et al, 2020 ; Burbelo et al, 2020 ; Casadevall and Pirofski, 2020 ; Guo et al, 2020 ; Liu et al, 2020 ; Zhao et al, 2020 ; Drobysh et al, 2022 ; Bian et al, 2022 ), targeting a broad range of infectious diseases such as influenza ( Fukuyama et al, 2020 ). In particular, antibody detection and quantification is essential to determine the SARS-CoV-2 antibody prevalence and monitor the temporal immune responses in vaccine recipients ( Valera et al, 2021 ; Theel et al, 2020 ).…”