AMPEROMETRIC IMMUNOSENSORS BASED ON RIGID CONDUCTING IMMUNOCOMPOSITES

Novel polishable immunosensors based on rigid biocomposite materials h ave been constructed. These biocomposites contain graphite powder, rab bit IgG, and methacrylate or epoxy resins, This material acts as a res ervoir for the biological molecules and as a transducer at the same ti me. In order to study the potential analytical properties of this new type of material, a competitive binding assay was developed to determi ne the RIgG present in a sample with the aid of goat anti-rabbit IgG l abeled with alkaline phosphatase. Using phenyl phosphate as a substrat e, the phenol produced by the enzymatic reaction was amperometrically detected at 800 mV (vs Ag/AgCl). The surface of the immunosensor can b e regenerated by simply polishing, obtaining fresh immunocomposite rea dy to be used in a new competitive assay.