A method for measuring concentrations of substrates in a sample liquid by using a biosensor

摘要

The present invention provides a method for measuring concentrations of the first and second substrates in a sample liquid by using a biosensor. The biosensor has an electrically insulating substrate, an electrode system, and a reaction layer including a first enzyme, a second enzyme and an electron acceptor. The method includes the steps of measuring a response current value I₁ of a predetermined period of time T₁ after supplying the sample liquid including the first and second substrates to the biosensor; measuring a response current value I₂ of a predetermined period of time T₂ after the supply of the sample liquid; obtaining the concentration C₁ of the first substrate corresponding to the current value I₁ based on the previously determined relationship between the concentration of the first substrate and the response current value of the predetermined period of time T₁ after the supply; obtaining a response current value I₁' corresponding to the concentration C₁ of the first substrate in the sample liquid based on the previously determined relationship between the concentration of the first substrate and the response current value of the predetermined period of time T₂ after the supply; and obtaining the concentration C₂ of the second substrate in the sample liquid corresponding to the current value calculated by subtracting the current value I₁' from the current value I₂ based on the previously determined relationship between the concentration of the second substrate and the response current value of the predetermined period of time T₂ after the supply.