| Abstract: | 表面電漿子共振(surface Plasmon resonance，SPR)是一種有名的光學量測技術且從20世紀初就開始運用至今。從1968年到1971年分別由Otto(Andreas Otto，1968)和Kretschmann(Erwin Krestchmann，1971)兩個人發表了稜鏡耦合的SPR光學架設之後才被漸漸認識。此後，因為SPR擁有高靈敏度的反應，常被用於量測薄膜層上極小的變化(Hass, et. al. 1970)。現在，經過多年的改良之後SPR應用於量測微生物間的反應，已有商業化的產品運用SPR技術，例如，GE Healthcare 公司製造了一系列的產品：Biacore T100, Biacore 2000, Biacore 30002…等等。 表面電漿子共振原理是當光從介電質介面進入金屬或半導體介面，在達到某個特定的角度也就是共振角時，會產生一個表面電漿波的漸逝波沿著介面上，而此共振角度與介面和介電常數有直接的關連性。運用此原理設計表面電漿共振儀器的光學偵測方式有四種：角度調制法、光強調制法、波長調制法、以及相位調制法，本研究採用相位調制法來設計一套表面電漿子共振量測系統。 五一相移法過去均運用在電子斑點干涉術(ESPI)中，用來求斑點干涉條紋相位資訊。由於表面電漿子共振系統運用於相位調制方法不多，本研究即結合五一相移法技術之相位調制技術設計出一套相位調制式表面電漿子共振的光醫量測儀器，並以此系統進行不同濃度乙醇的相位變化反應量測。從實驗結果驗證了結合五一相移法理論之表面電漿子共振相位調制法確實是可行的，且此一技術可減少干涉條紋圖片的拍攝量，降低雜訊的分析，成功提高整體系統效率。
Surface Plasmon Resonance (SPR) is a well-known optical detection technology and has been demonstrated in the beginning of the 20th century. It hasn’t been realized until Otto (Andreas Otto, 1968) and Kretschmann (Erwin Kretschamann, 1971) published their prism-coupling SPR optical setup in 1968 and 1971. Then, SPR had been used for measuring the tiny changes of the thin film layers (Hass, et. al. 1970) because it’s high sensitivity. Now, SPR has been applied to measure the bio-molecular interactions after the progressing of this technique for so many years. There are some commercial instruments for bio detection which adopts SPR technique. For instance, the Biacore of GE Healthcare companies brought out a series of products: Biacore T100, Biacore 2000, Biacore 3000, etc. The principle of Surface Plasmon Resonance (SPR) is that when a light beam is incident to the interface between the dielectric medium and the metal medium or semiconductor medium with a critical angle, a surface plasmon wave is excited. The critical angle directly correlates with the permittivity of the two media. There are four modulation methods to excite the SPR phenomena and they are also the basic principle to design the SPR system: angular modulation, wavelength modulation, intensity modulation, and phase modulation. In this research, the phase modulation was applied to design the system. The (5,1) phase shifting algorithm is used in electronic speckle pattern interferometry (ESPI) to retrieve the wrapped phase since it was demonstrated. In this research work, an opto-bio detection instrument based on the phase modulation SPR and the (5,1) phase shifting technology has been designed since there are not many SPR systems based on phase modulation. Moreover, the experimental results of different alcohol(C2H5OH) concentrations measured by self-designed system showed that (5,1) phase shifting technique works well with SPR modulation technology for the molecular interaction measurement. This system needs fewer interference fringe pictures, is successful to reduce the error and improves whole the system efficiency. |
