Transient measurement with an enzyme-immobilized electrode undergoing protein adsorption

A measurement without the influence of protein adsorption on the sensor surface has been developed using transient current of an enzyme-immobilized electrode. Response current decreases due to protein adsorption on the sensor surface and the enzyme-immobilized membrane causing glucose concentration gradient. By measuring glucose concentration in the transient state while controlling GOD activity, it is possible to prevent the influence of protein adsorption. A needle-type electrode glucose sensor on which enzyme is immobilized with a polyurethane membrane, with electrochemical on-off control of enzyme activity, is capable of accurate measurement of glucose concentration in bovine serum at least for 24 hrs.