Assay method with enzyme electrode system

摘要

A new electrochemical biosensor and method of its use. The electrochemical biosensor has a pair of electrodes consisting of a working electrode and a counter electrode made of the same electrically conducting materials. The counter electrode may be the same size or smaller than the working electrode. The biosensor includes a sample receiving portion wherein a portion of the electrode surfaces is covered by a reagent that includes a redox mediator and an enzyme. A fluid that contains an analyte is added to the sample receiving portion. A reaction involving the analyte, enzyme and redox mediator occurs. After this reaction is complete, an electrical potential difference is applied between the electrodes. Diffusion limited current is measured and correlated to the concentration of analyte in the fluid.