以數位微型反射鏡定址硫醇-烯化學改質之適體探針陣列電漿子晶片

Abstract

傳統上，表面電漿子共振生物感測器（Surface Plasmon Resonance biosensor, SPR biosensor）之表面修飾法（Surface functionalization）以硫金單層自組裝膜（Thiol- gold based Self-Assembled Monolayer, Thiol-gold based SAM）以及其衍生之相關技術為主流。在整個領域的大方向上，除了葡聚醣（Dextran）相關研究與應用外，以高分子層作為修飾方法之基材的研究並不多。由於以高分子層作為修飾層具有許多偵測應用上的優勢，本論文希望提出一套以聚對二甲苯（Parylene）作為基底之修飾方法學。本方法以針對硫醇基之探針分子，以紫外光觸發點擊反應來進行表面固定化。結合數位光源處理技術（Digital Light Process, DLP）系統來控制紫外光之曝光樣式，本修飾方法可以在晶片表面進行指定位置之「定址修飾」。 晶片製作部分，我們透過特殊化學氣相沉積系統來進行聚對二甲苯之鍍膜，並透過表面電漿共振角之偏移以及橢圓儀量測來計算膜厚。根據模擬結果，25 nm之膜厚為最佳化之參數。為進行紫外光曝光，我們以DLP4500 0.45 WXGA DMD為核心建構了一套紫外光曝光系統。此系統的曝光面積大小為10×15 mm2，單位面積之紫外光功率為1×10-4 W/ mm2，每個畫面最小切換週期為235 μs，並結合實驗室之表面電漿共振量測裝置進行即時監測。 為驗證修飾之效能，我們選擇了25-mer 核糖核酸探針分子作為修飾之模型。實驗結果顯示，我們可以在反應濃度1 μM 的probe DNA與5 mM的光啟始劑甲醇溶液，體積比例1：1之條件下，在1000秒內，修飾0.00902 RIU之核糖核酸探針分子。相對於，條件最佳化之硫-金修飾反應，反應速度約快8.9倍。我們透過開啟一半的DMD進行曝光修飾，驗證了定址修飾之效果。實驗結果顯示，UV光照射之區域，產生了1°的角度偏移。 論文最後一章，我們也針對未來技術之潛在議題與未來之發展方向，如在同濃度probe DNA條件下較傳統晶片具有更高的修飾量，進行探討。

Surface functionalization of Surface Plasmon Resonance Biosensor (SPR biosensor) is characterized by thiol-gold based self-assembled monolayer. In addition, there is not so many research and application of polymer layer, dextran for example, as a modified method of the substrate. In this study, we propose a method of surface functionalization using parylene as a linker layer, due to its advantages in the detection of applications. We use a probe molecule with thiol group to immobilize the sensing surface by a UV-triggered click reaction and import a digital light processing (DLP) system to control the exposure pattern of ultraviolet light. The modification method can be ‘‘Spatially Selective’’ on the sensing surface. In the fabrication section, we use a special chemical vapor deposition system to coat parylene and calculate the film thickness through the angle shift of SPR. According to the simulation results, the optimized thickness of the film is 25 nm. For UV exposure, we built a UV exposure system with DLP4500 0.45 WXGA DMD. The exposure area is 10×15 mm2, the UV power per unit area is 1×10-4 W/ mm2, and the minimum frame period is 235 μs. For real-time measurement, we use a SPR device of our laboratory. To verify, we selected a 25-mer probe DNA as a modified model. The results show that we can modify the probe DNA, and create 0.00902 RIU shift in 1000 seconds. The volume ratio of 1 μM probe DNA and 5 mM DMPA methanol solution is 1:1. Our reaction rate is about 8.9 times faster than sulfur-gold reaction and produces 1° angular offset in UV-exposure. In the last chapter of the thesis, we discuss the potential issues of future technology and development, such as in the same concentration of probe DNA conditions, our chips have high performance than the traditional chips.