奈米鉑修飾電化學偵測器及微流道電泳晶片結合電化學偵測器之研究

Abstract

摘要 本論文之研究主要以電化學為基礎，分別在電化學工作電極表面進行奈米材料修飾，以及將電化學偵測器整合至微流道晶片中進行分析應用。在電化學工作電極的修飾部分，選用了奈米材料作為修飾劑，藉由改變電極表面性質，可有效提升工作電極對於分析物的穩定度、靈敏度以及應用層面。本論文應用電沈積法在工作電極表面修飾奈米鉑，經由最佳的修飾條件，本修飾電極對乙醇展現了優良的偵測效果，不但擁有極佳的穩定性與再現性，還具備了高選擇性，可以在稀釋的含酒精飲料以及人類血清中，直接偵測乙醇的存在並進行定量，此修飾電極對於乙醇在飲料中的含量以及在生化臨床上的檢測，提供了一種快速而又簡單的應用。 微流道晶片目前在分離科學上的應用非常廣泛，在一個微型晶片中整合了進樣、處理、分離以及偵測等步驟，可以有效率地提升大量篩檢的效率。然而在微流道晶片的製程改進上，目前仍然有著相當大的改進空間。本論文針對微流道晶片新製程的研發以及電化學偵測器的整合加以研究，採用了乾式光阻作為微流道晶片的流道，再以自行設計的夾具固定整個晶片主體，成為可拆卸式的微流道晶片裝置，微流道可以拆卸清洗並重複使用，有效避免微流道污染，並增進微流道晶片製作的精準度與再現性，整個晶片系統對於兒茶酚胺(catecholamine)系列神經傳導物質的分離與偵測有著相當良好的分析效果。而電化學偵測器的整合部分，則利用銦錫氧化物塗佈(indium tin oxide coating)玻璃，結合微影蝕刻製程，製作出精準的薄膜式電化學電極組，包含了高壓電阻斷器、工作電極等，可將之整合至微晶片流道中，有效解決了自製電化學微流道晶片最常見的滲漏問題，並且以兒茶酚胺類化合物成功驗證其分析效能。以上兩種製程均對於電化學微流道晶片的製作方面，提供了新的製程發展。

Abstract The study of this dissertation is based on electrochemistry, including the modification of nano-materials on electrode for electrochemical detection, and the fabrication of microchip capillary electrophoresis (CE) in conjunction with electrochemical detection. In the part of modification of nano-materials on electrode, the platinum nanoparticles were used for the surface modification on working electrode by electrodeposition. In the optimal conditions of electrodeposition, the platinum nanoparticles modified electrode performed good detecting results for ethanol sensing. The performances of this modified electrode included good sensitivity, response time, selectivity, and reproducibility. The response time and sensitivity for different type of alcohol samples, including alcoholic beverages and human serum, was measured to evaluate the selectivity. The storage stability of the sensor was also evaluated. These characteristics allowed its application for direct detection of ethanol in biosensing and controlling. The applications of microchip CE are getting extensively. Microchip CE is characterized by a number of analytical advantages, including its rapidity, a small sample requirement and the potential for integration. However, the fabrication of microchip CE, including the chip material and types of detection, are needed to be improved. A dry-film photoresist-based microchip using a combination of photolithographic and hot-roll lamination techniques was employed in this study to improve the fabrication of microchip. The microchannel pattern was prefabricated in a dry-film photoresist tape using photolithographic methods. The integrated microchip device was then fixed in a laboratory-built Plexiglas holder prior to its application to microchip electrophoresis. The performance of this device as an electrochemical sensor was evaluated for the separation of neurotransmitters. The fabrication procedure described in this study is time- and cost-effective; it has great potential for use in the design and prototyping of disposable microscale analytical systems for a range of chemical and biochemical separations. A microchip integrated with electrochemical sensor which uses indium tin oxide (ITO) film electrodes as a working electrode and a decoupler was developed. The ITO film on a glass substrate was patterned by photolithography and wet etching as the decoupler and working electrode. This fabrication provided a way to solve the problem that the off-channel electrochemical detector integrated with microchip. The performance of this electrochemical sensor was evaluated by the separation of catecholamine. Excellent efficiency and resolution were obtained. This approach has a great potential for use in the fabrication of off-channel electrochemical microscale analytical systems for chemical and biochemical separations.