Research On SPR Biosensing Based On Side-polishing Multimode Fiber

With the progress of social economy,biomedical technology has also become one of the important indicators of social science and technology development.Biological detection problems have also caused widespread concern among researchers.The optical fiber surface plasmon resonance(SPR)sensor have many advantages,such as small size,immunity to electromagnetic interference,suitable for remote sensing and so on.When it is combined with biological monitoring,it also has the characteristics of mark-free and high sensitivity.Therefore,the combination of optical fiber sensing and SPR technology has great potential for bio-detection.Based on the research status of fiber-optic SPR sensors at home and abroad,an SPR biosensor based on side-polishing multimode fiber is proposed.The bio-functionalization of the sensor and biological protein test is performed.The main contents are summarized as follows.Firstly,the working principle of multimode fiber SPR is studied.The three-layer film structure model of side-polishing multimode fiber SPR is analyzed.The influence of coating thickness and polishing depth on the transmission spectrum of the sensor is investigated in detail.Secondly,the preparation process of side-polishing multimode fiber SPR sensor is studied.The relationship between polishing time and depth is analyzed.The refractive index sensing characteristic of multi-mode fiber with different polishing depth is measured experimentally.Different coating metal and thickness parameters are analyzed.The effects of gold film thickness and polishing depth on the refractive index sensing characteristic of the sensor are discussed.Thirdly,the refractive index sensing characteristics of near-water bionic solution based on side-polishing multimode fiber SPR sensor is studied.The experimental results of different gold film thickness sensors are analyzed and compared with the simulation results.Finally,the biofunctionalization of the side-polishing multimode fiber SPR sensor is studied.The method of protein surface fixation is analyzed for sensor.The bioprotein detection results are explored for different gold film thickness and polishing depth in sensor.