酸鹼值及葡萄糖氧化酵素 在葡萄糖檢測的研究及應用

Abstract

近年來生物晶片和生物感測器技術的蓬勃發展，為健康檢查帶來新的可能性。藉由將微型全分析系統整合在一個晶片上，藥品的生醫訊號將可被快速的紀錄、轉換、傳送，而後進一步的分析。為了檢測不同的藥品和生物分子，感測端需配入不同接收分子，藉以專一性的與待測物反應後再將訊號轉換成光電訊號。然而，為了在分析上提供更周全的環境觀測，且考慮到各式應用需配置不同的接收分子，我們期望生醫藥檢晶片的設計能具備萬用性，意即備載可分析各式生物分子或藥品之功能，且能同時觀測到當下藥品所處的環境溫度及酸鹼值，以取得最佳檢測環境條件。 有鑑於此，本實驗室欲研發一款可監控環境中酸鹼值與溫度值的生醫藥檢晶片來檢測藥品，而此篇研究著重於在網印電極上進行傳統電化學的分析，以取得本款晶片最適宜的分析藥物方式，為晶片未來改良後的應用鋪路。首先在環境監控方面下，本研究強調分析環境酸鹼值，透過選取不同酸鹼值下的葡萄糖作為分析物，建立酸鹼值、濃度對電流的關係圖，且此表可供後續晶片分析結果作為參照。 由於此晶片並無葡萄糖氧化酶鑲嵌其上，我們在網印電極上進行的電化學分析，會先透過定性的循環伏安法，找出適合晶片檢測出葡萄糖濃度的方式和反應電壓。由研究結果我們得知，葡萄糖在沒有葡萄糖氧化酶鑲嵌在電極上的情形下，需要透過加入電子傳遞物質進行抓電子，以佳化電極之間傳遞電子的反應、找出最適合的反應電壓供後續定量檢測，因此我們選取黃血鹽做為此電子傳遞物質，並且透過定量的計時安培法來建立檢測不同酸鹼值下的電流曲線。 在本篇中，我們提出一檢測方法以供晶片檢測出不同酸鹼值下的葡萄糖濃度，結果顯示，葡萄糖濃度與電流值呈正相關；而藥品在中性環境得到的檢測曲線較趨平緩，可以得知在中性環境提供較穩定的檢測環境；此關係曲線期望能在未來晶片的實際應用結果上供交相比對。

In recent years, development of biochips and biosensors technology has gained tremendous attentions for its potential in health checks. By integrating the complete micro-analysis system on a chip, biomedical signals can be recorded quickly and then read out by a transducer for further analysis. In order to detect different drugs and biological molecules, different receptors need to be equipped with different sensing end of each molecule; afterwards, the specific analytes reacted with those receptors will be measured via optical or electrical signal by signal converter. However, to avoid the inconvenience of employing various receptors, and to observe a comprehensive environmental changes, we expect pharmaceutical inspection chips capable of detecting a variety of biological molecules or drugs, and the corresponding surrounding temperature and pH values to obtain the optimal operating condittion. Concerning the matters mentioned above, we plan to develop a chip providing information of environmental pH value and temperature under different targets. But in the study, we mainly observe the changing curve of ambient pH value by electrochemical analysis over the traditional printed electrodes. Glucose is employed as the analyte for different pH values, and we obtain the figure of electric current as the function of environmental pH value and glucose concentration, which will play an important role in the development of our biochips. In this study, we conduct the experiment on the printed electrodes rather than ones embedded in glucose oxidase, and the electrochemical analysis is carried out by cyclic voltammetry to find out the preferable voltage. From the results, we find electrons transporting from solution to electrodes be done best by adding electronic substance. However, our chip is not embedded in glucose oxidase, so we add ferrocyanide in the solution to promote the electrons transportation, enhancing the signal detection. Next, quantitative chronoamperometry assay is applied to establish the relationship between analytes conditions and pH value. In this study, we develop an analyzing method in quantifying the influence of glucose concentration and different pH values on the corresponding electric current values. Results have shown that the measured electric current increases with higher glucose concentration, and the neutral state in pH provides a more stable environment for detection condition, of which the measured current changes little. Our results will support the further development of the chips, and the current measurement can be corrected in the practical test results in the future.