B型抗諧振反射光波導表面電漿子共振生化感測器之研製與其在即時免疫分析上之應用

Abstract

本論文研究一種適用於水中環境的B型抗諧振反射光波導 (ARROW-B) 結構之表面電漿子共振(SPR)感測器。B型抗諧振反射光波導的入射導光區較大，能有效和單模光耦合，且可藉由調整結構來控制導光效率。使用模擬分析光場在元件中的傳播特性，有系統地設計感測元件，使其在水環境下具有最佳化的感測靈敏度。在感測區前後的光場傳播區設計具上下對稱的光波導隔離層，使元件能穩定導光而不受外界環境影響，並於感測區附加液體流道設計，幫助生物分子附著於感測區表面進行反應。此外進行即時免疫分析上的應用，感測器針對G型老鼠免疫球蛋白分子可達約10-10 g/ml 濃度之偵測極限，並於10-10 ~ 10-7 g/ml的濃度與訊號變化具有線性關係。利用原子力顯微鏡可直接觀察到生物分子確於金表面形成鍵結，最後完成抗體-抗原專一反應之檢測。

In this thesis, an ARROW-B SPR sensor used in aqueous environment has been investigated. ARROW-B waveguide with a thick guiding region provides efficient coupling with a single-mode fiber, and the propagation behavior can be modulated by adjusting the structure. Modal characteristics of ARROW-B are analyzed with simulation and designed for obtaining optimum sensitivity in aqueous environment. The waveguides in front and rear of the SPR sensing region have symmetric cladding structure to improve the immunity against environmental changes, and the sensing region is configured with a liquid flow channel which assists bioagents in attaching to the gold surface for reaction. Then we submit the sensors in application to real-time immunoassay, and attain 10-10 g/ml of concentration of mouse IgG in detection limit. The power differences have a approximately linear relation with the concentration of mouse IgG between 10-10 and 10-7 g/ml. Using the Atomic Force Microscopy, the biomolecules binding to the gold surface are visualized. Finally, the specific immunoassay of antibody-antigen conjugate is demonstrated.