Investigation Of Wavelength-modulated Optical Surface Plasmon Resonance System And Its Application In Specific Recognition Of Biochemical Analysis

Surface plasmon resonance (SPR) is a new kind of sensing technology with high sensitivity, real-time monitoring and label-free samples. It is widely used in the field of food safety, environmental monitoring and biochemistry in recent years. This thesis is focus on the research of wavelength modulated optical surface plasmon resonance system and its application in biochemical analysis which includes the following major work.Firstly, SPR sensing mechanism and the key parameters that affect the performance of the sensor system such as the selection of the resonance region and the thickness of the metal film based on the classical coupling model-Kretschmann structure are simulated; Theoretical sensitivity for the detection of refractive index is calculated. The theoretical simulation results show that the designed wavelength modulated surface plasmon resonance system is preferable with the incident angle66°～80°, the corresponding resonance wavelength576nm-792nm and the thickness of the metal film45nm～55nm. The sensitivity for the detection of refractive index can reach10-5RIU.Secondly, based on the theoretical simulation results, a wavelength-modulated optical surface plasmon resonance system is developed. The key components such as the light source and the spectrometer is selected; The sample flow cell and the control of the external signals of the sample injection device are designed to achieve the integration of the signal transmission, reception and sample circulation; The real-time spectral analysis and monitoring is realized by Labview data processing and acquisition software; The prototype of the instrument is completed; The results of the detection of different refractive index and dynamic monitoring of the specific combination and dissociation process of different protein molecular show that the wavelength modulated SPR system has good response. In the short wavelength direction, the refractive index and the resonance wavelength has a good linear relationship while in the long wavelength direction has a good cubic polynomial fitting relationship.Finally, in order to fully apply the advantages of silver in SPR detection, improve the sensitivity of the sensing system, a noble film with multi-alternating metal layers of silver and gold is proposed. Theoretical simulation results show that the sensitivity of the six alternating metal layers of silver and gold has been significantly improved compared with two layers and pure gold. Expanding this theory to optical fiber coupling model, we proposed a high sensitivity fiber-optic sensor based on six alternating layers of silver and gold material. This thesis presents our fundamental research to SPR technology. We demonstrated a Wavelength modulated SPR system and a high sensitivity fiber-optic SPR sensor with multilayer film. Using these systems, we successfully detected sample solutions with different refractive indexes, also monitoring specific combination and dissociation of proteins, which provides solid foundation for future improvement and practicability of these SPR sensors.