金屬氧化物修飾電極發展環境及生醫感測器

Development of Metal Oxide Modified Electrodes for Environmental and Biomedical Sensors

呂晃志(Hoang-Jyh Leu)

指導教授 ： 林孟山

淡江大學/理學院/化學學系博士班/博士(2005年)

https://doi.org/10.6846/TKU.2005.00128

摘要

本研究主要利用不同金屬氧化物的氧化力及催化力開發環境及生醫相關的電化學檢測模式，並藉由流動注射分析、旋轉電極等系統配合各式電極表面修飾技術，建立具可行性的電化學偵測平台，用以發展具高度應用性之化學及生化檢測系統。
各種金屬氧化物的氧化力順序首先藉由電位法在各種溶液環境中快速評估，其結果與安培法所得結果直接進行對照，顯示其具有高度相關性，而本實驗所建立的金屬氧化物的氧化力順序，可提供本研究、後續實驗及其他電化學分析領域的參考與應用。
多巴胺在神經傳導機制中扮演相當重要的角色，但是體內的神經傳導物質極多，需兼具檢測上的高專一性，利用LiMn2O4對於多巴胺進行選擇性氧化之特性，可在雙電極的電化學流注分析系統中，建立低干擾的還原偵測模式，先以LiMn2O4進行氧化前處理，隨後再以空白玻璃碳電極施加還原電位偵測，不但能有效降低易氧化物質干擾，並能避免其他神經傳導物質的影響。
尿酸為生理上重要的核酸代謝產物，透過Pb3O4修飾電極之氧化力及催化力，即可在流動注射系統下建立單電極還原偵測模式，實驗上藉由Pb3O4修飾電極進行氧化反應，並隨即電催化氧化後之中間產物進行還原偵測，能有效降低環境中易氧化物質的干擾，發展非酵素型高專一性的快速檢測模式。
銨根為人體及環境之重要代謝物，利用Cu2O修飾電極之電催化特性，可在流注系統發展低電位氧化模式偵測，此機制亦可對於組織胺進行氧化模式偵測，或搭配共價修飾技術，結合creatinine deiminase酵素發展肌酸酐生化感測器，另外，在雙電極系統的上游電極修飾PbO2進行氧化前處理，可以避免環境中易氧化干擾物的影響。
乳酸去氫酶(LDH)是重要的血液生化檢驗項目，主要透過NADH的量測進而定量酵素活性，利用Mn3O4修飾電極的電催化特性，搭配旋轉電極系統，對於NADH建立低電位的氧化偵測模式，並藉由塗佈Nafion®高分子薄膜，即可有效降低易氧化物質的干擾；此外，將NAD+藉由選擇性高分子薄膜固定於修飾電極上，即可利用定電位安培偵測模式，快速定量LDH的酵素活性。
總而言之，本研究主要建立環境與生醫相關物質的檢測機制，藉由金屬氧化物的氧化及催化特性，發展簡易、靈敏、快速、低干擾的電化學檢測模式，有助於化學及生化感測器的發展，由於兼具實際應用的價值，可因應未來各種環境及生醫樣品的檢測需求；最後，本研究所建立的金屬氧化物氧化力表，也將提供未來在相關感測器開發及工業處理上的應用。

關鍵字

金屬氧化物 ； 感測器 ； 神經傳導物質 ； 多巴胺 ； 尿酸 ； 肌酸酐 ； 菸鹼醯胺腺嘌呤雙核苷酸 ； 乳酸脫氫酶

並列摘要

By using the chemical properties of metal oxides, the environmental and biomedical related electrochemical sensors have been developed in this research. The detecting schemes are based on the different oxidative or catalytic ability of metal oxide modified electrodes for ammonia ion, uric acid, creatinine, some well-known neurotransmitters, NADH and LDH, respectively. Either flow injection analysis system or rotating disk electrode system was used for the quantification of these analytes in this dissertation.
At the beginning of this research, various metal oxide modified electrodes were quickly evaluated the sequence of oxidative strength by potentiometry under various solution conditions. The potential versus Ag/AgCl was recorded to contrast the amperometric response by flow injection analysis, and a good correlation was found between these two methods. Therefore, the sequence of oxidative strength among metal oxides can be easily consulted and used throughout this research.
Dopamine, an important neurotransmitter in central nervous, was detected with limited interference in this experiment. The LiMn2O4 modified electrode was modified in upstream electrode to oxidize dopamine, and then the product was reduced in bare downstream glassy carbon electrode. This electrode can be easily fabricated by LiMn2O4 modified electrode and has the advantage of selective oxidation to avoid all the analogous neurotransmitters in biological applications.
Uric acid, an important metabolite form nucleic acid, can get a reductive response on Pb3O4 modified electrode. This modified electrode was used to oxidize the uric acid and then catalyzed the reduction of above intermediate on the same modified electrode. This method can effectively reduce the interferences without enzyme modification in the biomedical application.
Based on environmental and biomedical requirements, Cu2O was utilized to detect the ammonia ion in oxidative mode by flow injection analysis. This scheme was also used for histamine detection and the creatinine biosensor application. The creatinine deiminase for creatinine biosensor was modified onto the upstream of dual electrode. In order to obtain a limited interference system, PbO2 was used to pre-oxidize the easily oxidative compounds and also modified onto the upstream electrode in these biomedical or chemical sensors.
Because of the importance of dehydrogenase based sensors, the Mn3O4 was used to catalyze the oxidation of NADH in steady-state amperometry by rotating disk electrode. And this system was employed for the LDH activity evaluation by several electrode modification processes. This scheme can provide the advantages of rapid way and limit interference to obtain the result of enzyme activity through permselective membrane and Nafion® coating electrodes.
The results of these sensors can meet the requirements of biological and environmental applications. The unique strategies of metal oxide modified electrodes can provide the features of electrochemical schemes in various areas of analysis. And the sequence of oxidative strength among metal oxides can provide for the further application in other fields.

並列關鍵字

metal oxide ； sensor ； neurotransmitter ； dopamine ； uric acid ； creatinine ； NADH ； LDH

參考文獻

V. A. Sidorov, E.A. Ekimov, E.D. Bauer, N.N. Melnil, N.J. Curro, V. Fritsch, J. D. Thompson, S.M. Stishov, A.E. Alexenko, B.V. Spitsyn, Superconductivity in boron-doped diamond, Diamond Relat. Mater 14 (2005) 335-339.

Y. Miyahara, T. Maruzumi, S. Shiokawa, H. Matsuoka, I. Karube, S. Suzuki, Micro urea sensor using semiconductor and enzyme immobilizing technologies, Chem. Soc. Japan 6 (1983) 823-830.

J. Wang, Amperometeric biosensors for clinical and therapeutic drug monitoring: a review, J. Pharm. Biomed. Anal. 19 (1999) 47-53.

C. A. Galán-Vidal, J. Muñoz, C. Dominguez, S. Alegret, Chemical sensors, biosensors and thick-film technology, Trends Anal. Chem. 14 (1995) 225-231.

J. Janata, Chemical sensor, Anal. Chem. 62 (1990) 33R-44R.