Rapid, Multispecies Detection of SARS-CoV-2 Antibodies via a Meta-Surface Plasmon Resonance Biosensor

Figure 3

PEI-GNPs MetaSPR biosensor assay optimization: (a) procedure for the determination of S-trimer antibody using the MetaSPR biosensor; (b) PBST (pH7.45) base buffer supplemented with 2% (w/v) BSA was the best serum dilution buffer; (c) the maximum OD response in the sera of cats, dogs, and minks was obtained when the coating concentration of protein A was 7.5 µg/ml; (d) the maximum OD response when capturing the serum IgG of cat, dog, and mink was obtained when 7.5 µg/ml protein A was used for 15 min; (e) protein A, S-trimer antibody, and GNP-labeled S-trimer protein complex exhibited the maximum OD response after shaking at room temperature for 15 min. Data are shown as mean ± SD. Error bars represent the standard deviations from triplicates.

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