| 摘要 |
PURPOSE:To simplify and miniaturize the constitution, and also, to improve the reliability by leaving as it is a working electrode of one of two ion sensor use FETs and covering a working electrode of the other with a conductive molecule non-transmission film. CONSTITUTION:Potentiometric use working electrodes 1', 2' are stuck onto gate insulting films of a pair of ion sensor use FETs 1, 2, a working electrode 1' of one FET 1 thereof is covered with a conductive gas molecule non- transmission film 3, a working electrode 2' of the other FET 2 is left as it is, and a differential circuit of a source follower is constituted of these two FETs 1, 2. In a buffer solution 5 which has been separated by a diaphragm 4 for allowing a gas molecule to transmit through selectively, two FETs 1, 2 are placed, and the buffer solution 5 is grounded by a reference electrode 6. In this state, when the gas molecule is melted into the buffer solution 5 through the diaphragm 4, the FET 1 does not respond to dissolved gas since the non-transmission film 3 exists on a gate electrode. On the other hand, the FET 2 responds since the working electrode 2' for responding to the dissolved gas exists, and an output corresponding to the dissolved gas can be fetched without being subjected to the influence of the FET by the differential circuit. |
