Patent ID: 6225078
Filing Date: 2001-05-01
Classification: C12Q

Abstract:
A method for quantitative measurement of a substrate in a sample solution without interference from the presence of an easily oxidizable substance with a biosensor comprising an electrically insulating base plate, an electrode system having at least a working electrode and a counter electrode formed on said base plate, and a reaction layer including an oxidoreductase and an electron mediator in oxidized state disposed on said electrode system, said method comprising the steps of:contacting the sample solution with said reaction layer to react the substrate with said oxidoreductase to produce reduced oxidoreductase, wherein said reduced oxidoreductase reacts with said electron mediator to cause a reduction of at least some of said electron mediator, wherein reduced andunreduced electron mediator are obtained,applying a voltage between the working electrode and the counter electrode to electrochemically reduce said unreduced electron mediator at the working electrode, and measuring a reduction current flowing between the working electrode and the counter electrode, thereby quantifying the substrate.