Immobilization of antibodies onto gold and titanium oxide surfaces

The immobilization of antibodies onto surfaces by means of a reactive polymer has been studied. Two types of surfaces, gold and titanium oxide, were investigated. After modification with a suitable reagent bearing amino group, these surfaces are able to link covalently the reactive polymer through its N-hydroxysuccinimide carbonate functions. After polymer immobilization, a reaction between antibody and the remaining reactive sites on the polymer can take palce. This permits a covalent binding of biomolecules to the surface. The resulting biosensor is stable and specific. Another approach has been used for immobilization of antibodies: it involves a modification of the polymer with sulfonate groups and fixation of tetravalent metal ions. The resulting biosensor can recognize specifically the corresponding antigen and the regeneration of the surface between polymer and antibody layers is possible.