Biocompatible magnetic nanocomposites of Fe-AuNPs and poly(2-hydroxylethyl methacrylate) (PHEMA) were employed as a strategic protein immobilization platform. The hybrid magnetic nanocomposites were prepared by applying a 'grafting to' ATRP protocol. Fe-AuNPs having Fe core and Au shell were initially prepared by the inverse micelle method. Disulfide-containing PHEMA (DT-PHEMA) was grafted to the Fe-AuNPs surface by taking the advantages of the thiol chemistry. The grafting of DT-PHEMA to the Fe-AuNPs was confirmed by relevant spectroscopic analyses. The superparamagnetic property, a basic requirement for facile protein immobilization, of the magnetic nanocomposites was measured by the SQUID analysis. Lysozyme, gamma-globulins and bovine serum albumin (BSA) were immobilized onto magnetic nanocomposites via the adsorption strategy. The absorption intensity of lysozyme, gamma-globulins and BSA on the PHEMA grafted Fe-AuNPs were observed to be higher than that of bare Fe-AuNPs.