QUANTITATIVE METHOD OF SUBSTRATE

摘要

PROBLEM TO BE SOLVED: To provide the more highly accurate quantitative method of a substrate. SOLUTION: A biosensor having the electrode system comprising an acting electrode 4 and a counter electrode 5 formed on an insulating substrate 1 and a reaction layer including at least oxidoreductase and an electron acceptor is used. The change in concentration of material in the reaction between the substrate in a sample and the oxidoreductase and the electron acceptor is detected, based on the current response obtained by applying a voltage across the acting electrode 4 and the counter electrode 5. In this method, the application of the voltage for obtaining the current response is started from a potential E1 of the acting electrode 4 with the counter electrode 5 as the reference, and the current value at a potential E2 satisfying the condition of E2>E1 is detected as the current response after the elapse of the specified time from the application of E1.