Patent ID: 8524055

Claim:
A biosensor for measuring a component in blood, wherein the biosensor comprises: a first analysis portion comprising a first electrode system on which at least an oxidoreductase that acts upon the component and a mediator are provided, the first electrode system comprising a working electrode and a counter electrode; a second analysis portion comprising a second electrode system that comprises a working electrode and a counter electrode, a mediator being provided on the counter electrode but not on the working electrode; and a third analysis portion comprising a third electrode system that comprises a working electrode and a counter electrode, in the first analysis portion, the component in the blood is measured by causing a redox reaction between the component and the oxidoreductase in the presence of the mediator and detecting with the first electrode system a redox current caused to flow when a voltage is applied, in the second analysis portion, an amount of blood cells contained in the blood is measured by supplying the blood to the second electrode system, applying a voltage to the second electrode system in this state to cause a redox current to flow through the second electrode system, and detecting the redox current, in the third analysis portion, an amount of an interfering substance contained in the blood is measured by supplying the blood to the third electrode system, applying a voltage to the third electrode system in this state to cause a redox current to flow through the third electrode system, and detecting the redox current, and the working electrodes and the counter electrodes of the first, second and third electrode systems are made of gold, platinum, or palladium.