Enzyme Electrode for Hydrogen Peroxide by the Use of ISFET and Its Analytical Application

点击翻译按钮获取中文摘要

Developments of oxidation/reduction FET electrode(Redox-FET) and enzyme FET electrode which combined specificities of Redox-FET and enzyme were carried out in order to amplify the applicability of chemical sensor using FET (field effect transistor) and the following results were obtained:1. Measurement apparatus for single and triple electrodes with conventional and operational amplifier were constructed.2. FET electrodes by vacuum evaporation of various metals(Au, Pt, Au-Cr, Pt-Cr, etc.) on the gate of ISFET(ion-sensitive field effect transistor) were made. FET electrode by sputtering Pt had enough mechanical strength and Nernstian response(58-60 mV/decade) to hexacyanoferrate ( <II> / <III> ) system.3. Hydrogen peroxide (FET) electrode immobilized peroxidase(POD) was made. It has been ovserved that this electrode shows Nernstian response to 0.002-1 mM hydrogen peroxide in the buffer solution containing over 50 mM hexacyanoferrate( <II> ).4. Glucose (FET) electrode co-immobilized POD and glucose oxidase(GOD) was made and showed Nernstian response(58-60 mV/decade) to 0.02-1 mM glucose in the buffer solution(pH 9.0) containing 10-50 mM hexacyanoferrate( <II> ).5. We proposed simple numerical model for enzyme FET electrode and examined its propriety. Furthermore some consideration was under taken on its response mechanism.6. For the actual analysis of samples, standard addition method, calibration method and Gran's plot method were examined. Analytical values of control serum obtained by Gran's plot method showed to agree with certificated value.7. Hereafter, we will make micro-FET based on oxidation-reduction potential in cooperation with specialized manufacturer and study its analytical application.