電熱效應式石英晶體微天平應用於即時免疫球蛋白檢測

Abstract

當今生醫檢技術已蓬勃發展，石英晶體微天平因具有體積小、專一性、高靈敏度等優異特性被廣泛運用於檢測上。關於石英晶體微天平應用於生醫檢測相關實驗中，受限於微流體物理性質影響，使待測物無法充分與反應面辨識分子層結合，導致檢測時間過長且耗費成本。因此，本研究整合微機電製程技術與生物感測器成一優化檢測裝置做即時量測，利用電熱效應在反應槽中產生渦漩擾動微流體，提升待測物與感測器上辨識分子層結合機會，進一步促使鍵結量的增加。 實驗中利用石英晶體微天平來進行人類免疫球蛋白(Anti-Human IgG1)與相對應的抗原(Human IgG1)鍵結產生之質量負載做即時檢測與分析，並施加電壓10 Vpp與頻率10 MHz在微電極上，使電熱效應產生的電熱渦流提升免疫球蛋白原本只靠純自然擴散作用下的鍵結效率。 實驗結果呈現自然擴散環境下，分別在不同濃度抗原施加電熱力擾動反應槽內微流體，結果皆能提升鍵結量。此外我們亦利用螢光標定做定性的驗證，明顯佐證了電熱效應的效果。本文的研究，確實證明電熱效應確實能幫助生物分子提高鍵結機會，代表將電熱效應應用於生醫檢測上能為其效率提供助益。

Quartz Crystal Microbalance (QCM) biosensor has several advantages in analyzing the binding interaction among biomolecules, such as tiny size, specific binding and high sensitivity. Therefore it has been widely used as the equipment for biomolecule detection in the past few decades. Conventionally, most of existing studies utilizing QCM as bio-detection sensors have shortcoming with inefficiency, because of the limitation of the physical properties of microfluidics, analytes have difficulty to fully react with the immobilized ligand layer on the QCM sensor chip. An enhanced QCM is introduced in this study. It integrates with microelectromechanical technique and biosensor technique to produce electrothermal vortices flow in the QCM detecting chamber to increase the opportunity and efficiency of the binding of the immobilized ligand and the analytes carried in the fluid flow. In this study, a specific binding reaction of Human IgG1 - Anti-Human IgG1 protein pair is processed. The QCM chip is modified to integrate with the designed multi-microelectrode pairs, then operated the electrothermal effect, ETE, by 10 Vpp and 10 MHz to produce electrothermal vortices flow in reaction chamber. Ultimately, results of frequency reduction which enhanced by ETE effect were estimated. In the cases of different concentrations, the results show that there are notable improvenments in the reduction of resonant frequencies by comparing with those based on pure diffusion only, especially for the the case of low concentration. Simultaneously, the ETE effect gets further proved through immunofluorescence marker. Consequently, ETE is functional to enhance the mass-binding and improve the efficiency of detection.