Development of an electrochemical flow injection immunoassay (FIIA) for the real-time monitoring of biospecific interactions

Not only are sensors a revolution in analysis; they themselves are also exp eriencing a revolution brought about by parallel developments in sensor fab rication techniques and materials, polymer chemistry, signal processing met hodologies, the increased use of biomolecular processes as a means of analy te detection, and the coupling of sensors to other techniques such as flow injection analysis. Many of these developments have been incorporated into the present study, which we are undertaking in the development of our immun osensor technology. The system described here utilises screen-printed elect rodes which are low-cost, disposable devices that are simple to fabricate. Incorporated into our sensor is the electroactive polymer, polyaniline, whi ch brings about mediatorless redox coupling between the electrode and biomo lecular components attached to the polymer surface. This system also utilis es enzyme-labelled antibodies as the biomolecular recognition component for the analysis of the test analyte, biotin. The system has also been integra ted into a flow injection system. This has led to the monitoring of real-ti me antibody-antigen interactions using electrochemical methods and foreshad ows the development of single-step immunosensors. (C) 1999 Elsevier Science B.V. All rights reserved.