| 摘要 |
PURPOSE:To obtain a probe-type pH sensor having high sensitivity, resistance against strong acid and strong alkali and durability against long time dipping by joining a metal oxide semiconductor with a gate lead terminal of FET and covering the surface thereof with an organic thin film having proton permeability. CONSTITUTION:A supporting material 12 such as ceramics is covered with pH-sensitive films 11a and 11b. The film 11a comprises SnO2, In2O3, etc., and the film 1b is a film of polyvinyl chloride, etc., containing proper proton carriers. This element is connected with a gate of FET by way of a copper wire 6 and a joining material 13. The supporting body is worked to have a sharp end as a needle, so that the probe can be inserted easily into a cellular structure. By this constitution, a pH sensor having durability with a super small-sized probe can be obtained by using a commercial FET and pH can be monitored with good repeatability. |
