Design and Development of Handheld Surface Plasmon Resonance Meter

表面電漿子共振(Surface Plasmon Resonance, SPR)是一種光電耦合的物理現象，當光穿過介電質到達金屬時，使入射光的動量能匹配表面電漿子本身的動量，則能激發表面電漿子共振。表面電漿共振對金屬表面上的光學薄膜的特性變化相當靈敏，當此薄膜之光學特性發生改變，如折射率，便會反應在調制變數上。一般SPR的調制方法有角度調制、波長調制、相位調制、光強調制，本研究採用光強調制，因其具簡單、快速與高靈敏度之特性，相當適合掌上型機構的要求。表面電漿共振術在量測生物分子上具有免標記(non-labeling)、即時(real-time)、微量體積反應等優勢，因此被大量運用在研究生物反應上，我們視生物分子層為一光學薄膜，當生物分子產生鍵結或濃度上的改變時，量測反應前後光學特性之相對變化，繪製曲線，藉以觀察生物反應之特性。 本研究成功將光機架構從桌上型縮小至掌上型，以小尺寸背光模組配合拋物面鏡產生線平行光，進行平行量測，較傳統雷射光源以擴束方式進行平行量測，大量縮小機構體積，整個光機架構在4 x 6 x 1.5 cm3的體積大小，實現手持式表面電漿共振儀。對於光強調制最大的雜訊來源－環境光，採用密閉式機構設計，不透任何外部光源進入機構，除此之外，為了提升訊雜比，亦使用了參考光路的設計，將樣本光路之訊號與參考光路相減，消除光源的波動及環境的干擾。本研究所開發之手持式表面電漿共振儀以處理生物分子靜置反應為主，通過基本的酒精測試後，進行生物分子Human IgG與Anti-IgG的反應，完成了反射光強對時間的定性反應實驗，成功證實本系統之可行性。 由於進行實驗之資料未夠多，未來將與標準試液檢測，完成光強反射率與折射率之校正曲線，並由折射率推算反應濃度，朝定量分析發展。Surface plasmon resonance, SPR, is a charge-density oscillation that exists at the interface of two media with dielectric constants of opposite signs. When the momentum of incident light equals to the momentum of surface plasmon wave, surface plasmon resonance will be excited. The general ways of surface plasmon resonance modulation are angle modulation, wavelength modulation, phase modulation, and intensity modulation. Owing to the advantages of simple, rapid, and high sensitivity, intensity modulatuin meets the requirements of hand-held surface plasmon resonance meter. Surface plasmon resonance is sensitive to the thin film region that is about 150nm above the metal surface. The light inten-sity reflected by the metal responses to the changes of optical parameters of the thin film. In measuring bio-molecule interactions, surface plasmon resonance has the advantages of non-labeling, real-time, and small sample volume, so the sur-face plasmon resonance meter has become the leading technology in bio-sensing application. We view bio-molecules layer as an optical film, the changes of re-flective index produced by binding reactions and density changes are plotted to record the bio-molecules characteristic curve. The opto-mechanism volume has reduced from the table size to the hand-held size in this dissertation. Instead of using laser as light source, a 2 inch back-light module combined with parabolic mirror introduces parallel light to carry out milti-channels experiments. The whole dimemsions of handheld surface plasmon resonance meter are 4 x 6 x 1.5 cm3. To surpress the environmental noise, envi-ronmental light, a sealed mounting set was applied to allow no ambient light en-tering. Moreover, to improve signal to noise ratio, the reference channel was added in the optical path to cancel out the light source and temperature distur-bance. Handheld surface plasmon resonance meter is applied to antibody-antigen assay. After completing alcoholic test, the bio-molecules binding test, human IgG and anti-IgG, were than completed qualitatively. The obtained reflective intensity described the kinetic analysis and proved effectiveness of this newly develope.致謝 i 中文摘要 i Abstract ii 目錄 iii 圖目錄 v 表目錄 viii 第 1 章 緒論 1 1-1 研究背景 1 1-2 表面電漿共振術在生醫檢測上之應用 2 1-3 研究貢獻 3 1-4 各章節簡介 5 第 2 章 量測基本原理 6 2-1 背光模組與偏極片的基本光學性質 6 2-1-1 背光模組基本光學性質 6 2-1-2 偏振片之基本原理 9 2-1-3 薄膜光學 10 2-2 表面電漿子共振術 16 2-2-1 表面電漿波 17 2-2-2 表面電漿子共振之激發 18 2-2-3 表面電漿子共振調制種類 21 第 3 章 手持式表面電漿子共振儀 25 3-1 系統設計理念 25 3-2 光路佈局與設計 26 3-3 光機系統之設計與元件之選擇 30 3-3-1 光源 30 3-3-2 驅動波長 32 3-3-3 背光模組 34 3-3-4 拋物面鏡 34 3-3-5 稜鏡 37 3-3-6 支撐固定機構設計Mounting 39 3-3-7 入射角度之設計 40 3-4 校正系統光路 42 3-4-1 拋物面鏡校準 42 3-4-2 入射稜鏡位置校正 44 3-5 應用電路設計 48 3-5-1 電流源電路設計 48 3-5-2 訊號處理電路 51 第 4 章 實驗結果與討論 53 4-1 實驗模擬 53 4-1-1 鍍膜比較模擬 53 4-1-2 實驗模擬 59 4-2 實驗結果 63 4-2-1 空氣、水、酒精之定性實驗 63 4-2-2 ELISA生物樣本實驗 65 第 5 章 結論與未來展望 69 5-1 結論 69 5-2 未來展望 69 參考文獻 7