Antibody immobilization for biosensing on gold-coated magnetite nanoparticles surface

Surface gold coverage of Fe3O4 nanoparticles were prepared and approved by various characterizations. The saturation magnetization of the gold-coated nanoparticles remains almost unchanged (less than 1 emu·g−1) for long storage periods more than 2 months. Then the antibody immobilization for biosensor application was conducted and compared with colloidal gold nanoparticles and parent magnetite nanoparticles. The antibody immobilization yield of these nanoparticle surfaces were investigated in terms of ELISA (Enzyme-Linked Immunosorbent Assay). The gold-coated magnetite nanoparticles demonstrated a best immobilization; such endurability under biochemical environment enabled themselves as promising carriers for biosensor applications.