ENZYMELEKTROD

The invention relates to enzyme electrodes which are able to respond amperometrically to the catalytic activity of the enzyme in the presence of its respective substrate and comprise the enzyme immobilized or adsorbed on the surface of an electrically conductive support member, which consists of or comprises a porous layer of resin-bound carbon or graphite particles, which particles are intimately mixed with, or have precipitated or adsorbed on the surface of the individual particles before binding to form said layer, a finely distributed platinum group metal, in order thus to form a porous substrate layer on which said enzyme is adsorbed or immobilized and comprises an essentially heterogeneous layer of resin-bound carbon or graphite particles, with said platinum group metal dispersed essentially uniformly through said layer. The preferred substrate materials are resin-bound platinized carbon paper electrodes comprising platinized carbon powder particles with colloidal platinum adsorbed on the surface of the particles and bound to a carbon paper substrate using a synthetic resin, preferably polytetrafluoroethylene, as binder. The advantageous enzyme electrodes are glucose oxidase electrodes comprising glucose oxidase adsorbed or immobilized on the surface of the substrate.