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

为了扩大场效应晶体管（FET）化学传感器的适用范围，结合氧化还原FET电极（Redox-FET）和酶FET电极的特性，进行了氧化还原FET电极和酶FET电极的研制。采用常规放大器和运算放大器搭建了单电极和三电极测量装置.通过真空蒸发各种金属（Au、Pt、Au-Cr、Pt-Cr等）的FET电极在离子敏感场效应晶体管（ISFET）的栅极上制备了一种新型的金属氧化物半导体材料。溅射Pt的FET电极具有足够的机械强度和对铁氰化物（/）体系的能斯特响应（58-60 mV/decade）<II><III>.制备了固定化过氧化物酶（POD）的过氧化氢（FET）电极。已经观察到，该电极在含有超过50 mM六氰高铁酸盐的缓冲溶液中对0.002-1 mM过氧化氢显示能斯特响应<II>。制备了共固定化POD和葡萄糖氧化酶（GOD）的葡萄糖（FET）电极，并在含有10-50 mM六氰基高铁酸盐的缓冲溶液（pH 9.0）中对0.02-1 mM葡萄糖显示能斯特响应（58-60 mV/decade）<II>。提出了酶场效应管电极的简单数值模型并检验了其合理性。此外，还对其反应机制进行了一些考虑。在实际样品分析中，考察了标准加入法、校正法和Gran's作图法。用Gran's作图法测得的对照血清分析值与标准值一致.今后，我们将与专业厂商合作，制作基于氧化还原电位的微型场效应管，并研究其分析应用。

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.