Fig. 1: Schematic illustration of the surface functionalization of IMA and spike protein immobilization.
From: Label-free impedimetric immunosensor for point-of-care detection of COVID-19 antibodies
a Hydroxyl groups produced on the glass surface upon plasma exposure react with APTES to form SAM with surface -NH2 groups, b MUOH forms SAM with surface -OH groups on the Au surface, and c MUA forms SAM with surface -COOH groups on the Au surface. The -NH2 group reacts with SA to functionalize the surface with -COOH groups in b, c, which on subsequent application of EDC/NHS conjugation chemistry led to covalent immobilization of the S-proteins (
).
