An electrochemical impedance method has been developed for the specific detection of immunological interactions between human mammary tumor associated glycoproteins and its monoclonal antibody (GP1D8). Antibody proteins were immobilized through oriented covalent coupling onto AT-cut 9MHz quartz crystals microbalance (QCM) transducer. The experimental set-up for studying the immunological response consists of a differential measurement system that allows extraction of only the immunological signal. Consequently, measurements of the electrochemical impedance spectra (EIS) of gold electrode coated with the antibody showed changes of the a.c. current response after the addition of the specific antigen. The successful immunological reaction between the immobilized antibody-antigen could thus be monitored.

Key words: BREAST CANCER, ANTIGENS, IMMUNOASSAY, MONOCLONAL ANTIBODY, IMPEDANCE