The synthesis of a terminally thiolated poly(vinyl)alcohol (PVA) grafted with Poly (acrylic acid) (PAA) side chains is described. The PVA-PAA graft polymer (PVAg) was end-tethered to silver surfaces via the terminal thiol functionality and the resultant mobile, hydrophilic polymer matrix exploited for the covalent immobilization of large quantities of polyclonal goat (anti-hIgG) antibody (IgG) with low levels of non-specific adsorption. An SPR immunosensor, fabricated with an IgG-PVA-silver interfacial layer proved capable of performing a sensitive label-free assay of human IgG antigen (hIgG) with minimal non-specific binding interference. A detection limit (DL) for hIgG from serum of 0.8 microgram/ml (5 nM) and an assay sensitivity of 0.66 ng hIgG/mm2/nM are reported.
