title: A computerised enzyme immunosensor: application for the determination of antigens.
abstract: The present report gives preliminary results of a new sensitive method for the amperometric determination of antigens in serum. This method, developed from the biological model 'hepatitis B surface antigen antibodies' is less time-consuming than most immunochemical techniques, and eliminates many inconveniences arising from use of isotopes. Specific antibodies immobilised onto a gelatin membrane are applied in a solid phase 'sandwich' procedure. The antibodies are labelled with glucose oxidase. The measurement consists of an immunological process and an enzymatic reaction. The second part is carried out by fixing the active membrane onto a pO2 electrode. The sensor is immersed in a standard glucose solution and a signal is obtained by measuring the consumption of oxygen due to the enzyme reaction. This response is correlated to the antigen concentration of the sample. It is a function of both the diffusional and the reactional characteristics of the active layer. Under software conditions, the signal is sampled when the stationary state is obtained. The difference between initial signal and the stationary state signal is measured and compared with the pre-set calibration curve. Use of the computerised enzyme immunosensor could easily be extended to assay of other antigens and haptens that are usually determined by radioimmunoassay.
mesh_terms: D000917:Antibody Formation; D000941:Antigens / Q000032:analysis; D003201:Computers; D004566:Electrodes; D004800:Enzymes, Immobilized; D005949:Glucose Oxidase / Q000276:immunology; D006241:Haptens / Q000032:analysis; D006514:Hepatitis B Surface Antigens / Q000032:analysis*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007124:Immunoenzyme Techniques / Q000295:instrumentation*
chemical_list: D000941:Antigens; D004800:Enzymes, Immobilized; D006241:Haptens; D006514:Hepatitis B Surface Antigens; D005949:Glucose Oxidase