以石英晶體微天平為平台整合表面電漿共振與電化學阻抗分析之生醫量測系統開發與研究

Abstract

生物分子彼此之間的親和力研究一直是生醫領域內的重要課題，由於分子間彼此作用的反應過程相當複雜，因此量測參數的增加有助於得到更完整的資訊。本研究嘗試以石英晶體微天平為平台，結合表面電漿共振的光強變化與電化學組抗分析的阻抗圖譜分析，架設可同時量測此三系統參數之整合平台。 本研究透過將石英晶體微天平之下電極改成ITO電極的方式，以稜鏡耦合在石英上方之金電極激發表面電漿共振；在電化學阻抗分析方面採用與石英晶體微天平共用電極的方式以切換電路進行整合。希望能在不對原始架構進行太多改變的情況下，使三種生物感測器皆能保持其原有的量測特性。 本研究經由實驗證明以稜鏡耦合的方式加以整合會使石英晶體微天平之量測值偏離其原有理論模型，因此無法以此種方法整合這三個系統。但在石英晶體微天平與電化學阻抗分析、表面電漿共振與電化學阻抗分析的整合上皆取得成功。

Bio-affinity measurement is always an important issue in bio-technology research field. Since the interaction process between bio-molecules is complex, more parameters are needed for facilitating the analysis. In this study, Quartz Crystal Microbalance (QCM) was provided as a base platform. Surface Plasmon Resonance (SPR) and Electrochemical Impedance Spectroscopy (EIS) functions were added on QCM to form a novel integrated system. That is, the change in resonance frequency and dissipation factor from QCM, the optical power change from SPR and the Impedance change from EIS could be simultaneously measured. In this system, the bottom electrode of QCM was replaced with ITO and the prism coupling was used to excite SPR. The upper electrode of QCM was used as the working electrode for EIS function and a switching circuit was used for measurement of this two system by turns. The infrastructure of this integrated system not only provide multi-parameter measurement but also keep their own features. According to our experimental results, we found that the use of coupling oil changed the features of QCM. That means there exists some problem when integrating these three system with prism coupling excitation. But the integration of QCM and EIS, SPR and EIS is successful.