| 摘要 |
PURPOSE:To allow the quantitative determination with a slight amt. of a sample with high accuracy and to eliminate the need for washing of a sensor at every measurement by using a biosensor having an immobilized enzyme film provided on the surface of an oxygen permeable film and an internal electrode connected via a buffer soln. CONSTITUTION:The biosensor 1 consisting of an immobilized enzyme film fixture 2, the immobilized enzyme film 3, the oxygen permeable film 4, and the electrode body 5 exhibits a specified current as the oxygen past the films 3 and 4 from the atm. air is electrolytically reduced continuously. The concn. gradient of the oxygen is, therefore, made in the film 3 and the current value is unequivocally determined by the oxygen concn. on the surface of the film 4. An enzyme reaction progresses immediately and the oxygen is consumed when a slight amt. of the sample soln. contg. a substrate is dropped onto the film 3 by a microsyringe, etc., in this state. The oxygen concn. on the film 4 is then decreased and the reduction current is decreased. An equil. point is attained when the substrate in the reaction liquid decreases to some amt. The concn. of the oxygen restores the state before the dropping of the substrate when the equil. point of the reaction is passed. The enzyme reaction attains the equil. state in a short period of time in such a manner and restores the initial oxygen concn. Since the reduction current restores the initial value as well, the measurement of another sample is possible again. |
