以氧化銦鎵鋅薄膜電晶體生物感測器探討蛋白質與配體反應之動能

Abstract

在這篇論文中介紹以氧化銦鎵鋅薄膜電晶體與感測金屬電極組成之生醫感測器偵測微小的生物分子，並深入探討其混合反應及動能變化，此研究分兩部分： 在第一部分，分析生物素與鏈親和素的混合情況，我們採用Y型微流道。此外，使用聚二甲基矽氧烷來密封微流道系統以避免待測物溶液的蒸發。接著先分別量測生物素與鏈親和素的電流訊號，以定義待測物的擴散時間。然後進行一系列同時與時間差的混合實驗。藉由觀察即時的電流變化，來分析待測物在流道中的混合狀況。最後我們使用牛血清白蛋白做為對照組，以驗證薄膜電晶體生醫感測器之非特異性結合的情況。 在第二部分，為了進一步分析蛋白質與配體反應之動能變化，我們將含有溶菌酶以及三乙醯殼三糖的生物溶液注入聚二甲基矽氧烷來密封微流道系統去感測其電流訊號。我們預先將溶菌酶以及三乙酰殼三糖混合在微小型的塑膠離心管，並且控制兩者的反應時間;可以發現到溶菌酶與三乙酰殼三糖之生物化學反應隨時間不斷地在逐漸進行，最後會趨於平衡狀態，另外我們混合不同濃度比的溶液去觀察反應後的結果。最後我們利用基本化學公式將速率常數得出。

In this thesis, a biosensor consists of an Indium-Gallium-Zinc-Oxide (IGZO) thin film transistor (TFT) biosensor and a gold sensing electrode is demonstrated for detection of biomolecules. We further investigated the mixing reaction and kinetics of biomolecules. There are two parts in this thesis. In the first part, to analyze the mixture condition of streptavidin and biotin, a Y-type external microfluidic channel is demonstrated. In addition, the channels are sealed by polydimethylsiloxane to avoid evaporation of the target analyte solutions. Next, the current signals of streptavidin and biotin are measured to define the diffusion time. Then, a series of mixture and time delay experiments are conducted. By observing the real-time current change of the TFT biosensor, the mixture condition of the reaction can be analyzed. Finally, bovine serum albumin (BSA) is used for a control experiment to verify the specificity and reliability. In the second part, to further analyze the reaction kinetics of protein and ligand, we injected the mixing solution of lysozyme and tri-N-Acetylglucosamine (tri-NAG) into the PDMS microfluidic channels. We controlled the reaction time by incubation the mixing solution of lysozyme and tri-NAG in the microcentrifuge tubes. The biochemical reaction proceeded by time and gradually reached the equilibrium state. Also we mixed the different concentration ratios of solution to observe the reaction results. Finally, the rate constant and is derived by basic chemical equations.