JPS643551A - Functional electrode - Google Patents

Abstract

PURPOSE:To stabilize sensitivity by enclosing a thin functional film contg. the bioactive protein on an electrode with a wall material having a small hole and filling an aq. soln. in the space. CONSTITUTION:The functional electrode A is formed by fixing the solid film (b) contg. the bioactive protein to a part on the surface of the electrode (a) on a base plate (k). The film (b) is enclosed with the wall material (d) and the electrode (a). The aq. protective soln. (e) is filled in the enclosed space. The material (d) has the small hole to allow leakage to the liquid (specimen liquid) on the outside of the electrode A and the components of the specimen liquid diffuse into the space and arrive at the film (b). Sensing is thus executed. Since the part of the electrode (a), except the part where the film (b) is deposited, is electrically insulated from the outside world, the base plate (k) is constituted of an insulator and both the front face and side faces of the electrode (a), except the part where the film (b) is deposited, are coated with the insulator (g). The diameter of the small hole of the material (d) is preferably <=0.3mm. The stable sensitivity and sensing sensitivity are thereby obtd.