Fig. 1.

Schematic representation of the DNA-assisted Nanopore Assay for multiplex quantification of SARS-CoV-2 antibodies. Step 1: IgG and IgM captured by the N-protein modified MBs. Step 2: Formation of the sandwich structure between MBs, IgG or IgM antibody, and probe DNA modified AuNPs. Step 3: Dehybridization of the probe DNAs from the AuNPs. Step 4: Magnetic separation of probe DNAs from the remaining sandwich complex. Step 5: Quantification of probe DNAs to derive the concentration of IgG and IgM, respectively.