| 摘要 |
PURPOSE:To measure the concentration of solute with a high selectivity, by employing iridium oxide for an ion sensitive film of an ion sensitive field effect transistor (ISFET) to immobilize an enzyme. CONSTITUTION:A biosensor of a separate gate type ISFET has an FET5 partly on a silicon of a substrate 1 and form an iridium oxide (OIr) film 2 of an ion sensitive film separated therefrom. The FET5 is connected to the film OIr2 with a conductor 6 and the film OIr2 is insulated with an insulating film 4. An enzyme film 3 is immobilized on the film OIr2. For example, urease or glucose oxidase is immobilized to make a urea sensor and a glucose sensor. The biosensor is immersed into a liquid to be inspected to be made to react with the enzyme and a substrate and potential changes due to pH is detected with the film OIr2. Thus, the direct coating of the iridium oxide with an immobilized enzyme film enables highly accurate measurement of the concentration of the substrate. |
