高敏感度銦鎵鋅氧化物薄膜電晶體於EB病毒蛋白質檢測應用

Abstract

在這篇論文中，我們以氧化銦鎵鋅薄膜電晶體並附有延伸金感測板構成生醫感測器檢測蛋白質。電晶體扮演著感應與訊號輸出的角色，而金感測板具有傳導蛋白質電荷到電晶體通道層以改變通道電流的功能。我們在此研究中測試了兩種蛋白質，一種則是小鼠血清裡的免疫球蛋白G，一種是人類皰疹病毒第四型(EBV)的抗體。在免疫球蛋白G的檢測中，我們利用氧化鋅奈米柱對感應區表面作改質，並藉由其高面積對體積比例而感善了感測器的靈敏度。在人類泡疹病毒第四型的檢測中，我們利用自組裝分子層及蛋白質交聯劑來作改質，為的是改善蛋白質的固定化。進一步地，我們還運用了上閘極電壓變化的分析來增加實驗的可靠性與可重複性。最後，我們將生醫感測器與目前現有的蛋白質檢測方法做比較，省時、高敏感度是我們感測器的顯著優勢。我們可以在10pg/ml離體的小鼠血清溶液中量測到濃度為8.98fM的小鼠免疫球蛋白G。並且專一性地量測到濃度為10pg/ml的EBV抗體溶液。

A biosensor structure consisting of an Indium-Gallium-Zinc-Oxide (IGZO) thin film transistor (TFT) and a gold extended sensing pad was demonstrated. The IGZO-TFT was the device for signal extraction, and the sensing pad could conduct protein charges resulting channel current changed. There were two kinds of target protein in the thesis, mouse IgG in the mouse serum and Epstein-Barr virus antibodies. In the detection for mouse IgG, the biosensor was functionalized by applying ZnO nanorods on the pad to modify the gold surface. ZnO nanorods improved the sensitivity of the biosensors by high surface-to-volume ratio. In the detection for EBV antibodies, the device was functionalized by self-assembled monolayer and crosslinker to solve the problem of protein immobilization. Furthermore, the top gate voltage analysis was employed to improve reliability and repeatability of the experiment. Finally, the TFT-biosensor was compared with the conventional methods for protein detection. Time-saving and high sensitivity were the significant advantages of the TFT biosensor. The bio-TFT is able to selectively detect 10pg/ml mouse IgG in the serum solution and 10pg/ml EBV antibodies in the buffer solution.