DEVELOPMENT OF ELECTROCHEMICAL IMMUNOSENSING SYSTEMS WITH RENEWABLE SURFACES

The repeated use of immunochemically modified solid phases in electroc hemical immunosensor analysis is the driving interest of this work. Tw o new strategies have been developed. One of these strategies is aimed at the development of a manual methodology. It comprises the construc tion of amperometric immunosensors based on rigid biocomposites. These biocomposites are formed by a conducting polymer composite matrix tha t acts as a reservoir of an immobilized immunologic material. The surf ace of the biocomposite can be renewed by a simple polishing procedure . The second strategy involves the design of an automatic methodology. It features an immunochemical analytical system using flow injection techniques. The potentiometric detection uses a solid phase formed by immunologic reagents immobilized in magnetic particles. These particle s are fixed to the sensor with the use of a magnetic field. The renewa l of the reactive surface is achieved by the release and activation of the restraining magnetic field and the manipulation of the flow. The analytical properties of these immunosensors were evaluated measuring RIgG using a competitive technique and measuring GaRIgG with a sandwic h methodology. The labelling enzymes of the immunoconjugates were pero xidase in amperometric measurements and urease in potentiometric measu rements. (C) Published by Elsevier Science Limited.