| Summary: | 碩士 === 國立臺灣海洋大學 === 系統工程暨造船學系 === 98 === 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.
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