| Summary: | 碩士 === 國立成功大學 === 醫學工程研究所 === 83 ===
Electrochemical techniques had been proved to be significantly advantageous to the biosciences. Enzymes Immobilized at electrode surface fo detecting biochemical substances had been developed in recent years. Some of organic and inorganic redox chemicals are used as a mediator for promoting electrons transfer between enzymes and electrode. In addition, some conducting polymers were introduced to this system according to its electric conductility and the ability for enzyme immobilizing simutaneously. Based on the default of preparation and application of the electrode, we tried to establish a simple concept of enzyme electrode, we used particle of a platinum family -- palladium (Pd) to build an efficient electrocatalytic system for the oxidation of peroxide (H2O2).
Pd microparticle was electrodeposition on a GC electrode, and then dipped the mixed solution of glucose oxidase (GOD) and GA on it. The resulting electrode showed a large decrease in overvoltage for the oxidation of H2O2. Namely, we can monitor the concentration of glucose quantatively under a lower controlled potential. Moreover, we discussed the effect of a polyphenylenediamine (PPD) film by electropolymerization on the resulting electrode. We obtain a good condition on preparing PPD film which could facilitate H2O2 oxidation and prevent the interfer substances (e.g. uric acid and ascorbic acid). This enzyme electrode showed a linear glucose response (0.025~0.8 mM) at + 0.5V vs. SCE, and the detection limit is about 10 mM. GOD and HRP coimmobilized in Pd/GC electrode. HRP could directly transfer electrone in the surface of electrode by the help of Pd particles. The working potential could also reduce to 0 V for detecting glucose. These bienzyine electrode would reduce the effect of interference under this potentiala, and showed a linear glucose response (0.05~2 mM). For expanding the linear rang, we tried to apply oxygen-rich biomedical material (such as hemoglobin and myoglobin) in the enzyme electrode for suppling oxygen which comsumpted in the enzyme reaction. These material maybe have better efficiency of suppling oxygen in our current experimental results, which could expand the linear range in detecting glucose.
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