- 學位論文
稜鏡耦合表面電漿共振感測器之研究
Investigation of Surface Plasmon Resonance Sensors based on Prism Couplers
摘要
表面電漿共振表面(SPR)是金屬和介電材料之間的界面中發生的一個物理現象。利用SPR的生物感測器能提供各種各樣的優秀特性例如高靈敏性、即時檢測、無需標定的前處理和即時檢測。因此，SPR生物感測器經常被生物檢測和免疫化學利用。 在這篇論文裡，首先我們模擬兩種黏附層-鈦和鉻的SPR 結果和測量他們的實驗SPR。 從比較的結果得知使用鈦為黏附層的SPR基板可以獲得較小的半高寬和較低的反射率。之後，我們討論金膜厚度對SPR的影響。透過Matlab模擬不同金膜厚度的SPR 結果，並且與其的試驗數據相比較。不論實驗或模擬的結果，皆說明47奈米金膜展現最好耦合效率和最小的反射率。同時，我們也發現共振角改變量和不同的分析物呈現高度敏感性，但共振角改變量和厚度沒有直接影響性。 更進一步，我們利用SPR生物感測器的革新特性，來研究生物素和streptavidin之間的反應。我們看到注入不同濃度的streptavidin 時SPR展現出它的高靈敏性；即使10-8 M streptavidin可以被量測出。另外， 我們改變streptavidin的通入流速，但是對共振角改變和偵測時間上並沒有明顯地改變。由此得知生物素和streptavidin之間是整個鍵結的反應決定步驟。 目前我們正努力發展和改進下一代SPR生物感測器的性能，例如成本降低、微小化可攜式SPR和增強其靈敏度。
並列摘要
Surface plasmon resonance (SPR) is a physical phenomenon which occurs in an interface between metal and dielectric materials. A biosensor based on SPR can provide various excellent characteristics such as high sensitivity, rapid examination, label-free pretreatment, and real-time monitor. Thus, an SPR biosensor is often utilized for biodetection and immunochemistry. In this thesis, first we simulated SPR results of two kinds of adhesion layers, titanium and chromium, and measure their experimental SPR results. Both simulations and observations confirm that the SPR curves with titanium display narrower FWHM and lower reflectivity than those with chromium because of smaller internal damping within titanium. Next, we discuss the influence of thicknesses of gold film on SPR. The simulated SPR results of various thicknesses of gold film by Matlab are compared with their experimental data. Our experimental results indicate that a gold layer of 47 nm thick presents the best coupling efficiency to exhibit the deepest reflectance minimum, which is in a good agreement with our numerical simulation. Furthermore, we also observe that the angle shift of the reflectance minimum is highly sensitive to different analytes attached on the surface of the gold film but independent with its thickness. Furthermore, we utilize the aforementioned innovative properties of the SPR biosensor to investigate the binding condition of biomolucules. A couple of high affinity biomolecules, biotin and streptavidin, are adopted to examine the functions of the home-made SPR biosensor. First, the pretreatment of self-assembly is used to immobilize the biotin on the gold film of SPR substrate, and the characteristic absorption peaks of FT-IR of the biotin indicate that indeed the biotin anchors on the gold film. Afterwards, the measurements of various concentrations of streptavidin by home-made SPR system display its high sensitivity; even the 10-8 M of streptavidin can be detected. In addition, we increase the injection rate of streptavidin solution but there is not a significant change because the determining step of kinetic theory is the binding between the biotin and the streptavidin. Currently we are further developing and improving the performance of our SPR biosensors including reduction of cost, miniaturization for portable SPR sensors, and enhancement of the sensitivity for the next generation of SPR systems.