Research On Fiber-optic Microfluidic Biosensing Technology Based On Surface Plasmon Resonance

The microfluidic optical fiber surface plasmon resonance（SPR）sensor has the characteristics and advantages of both the microfluidic and the optical fiber SPR sensing technologies,such as low sample consumption,high sensitivity,good detection stability,and wide application field.In this thesis,the main research content is to explore the microfluidic optical fiber SPR sensing technology and its application in biological detection,and the corresponding research work has been carried out.Based on the multilayer dielectric film model of the optical fiber SPR sensor,the influences of structural parameters such as the core diameter,the length of the sensing zone,the metal and its thickness,and the thickness of the adhesion layer on the performance of the optical fiber SPR sensor were calculated,and the corresponding influence laws were summarized and analyzed.The optical fiber SPR sensors and the polycarbonate chips were prepared by magnetron sputtering and micro-milling method,respectively.In order to improve the packaging strength of the microfluidic chips,the process of low-temperature plasma modification on polycarbonate was explored.The prepared microfluidic chips was packaged and integrated with the optical fiber SPR sensors,and the microfluidic optical fiber SPR sensors were realized.A wavelength modulated microfluidic optical fiber SPR sensing system was constructed.The refractive index sensing experiment on sodium chloride solution with different concentrations was carried out,and the sensitivity of the sensor for refractive index detection was 1949 nm/RIU.Glucose concentration detection and surface functionalization of the sensor were carried out.The detection sensitivity was increased from 0.2668 nm·（mg/m L）^-1before functionalization to 12.5nm·（mg/m L）^-1 after functionalization.Research work in this thesis reveals the effect laws of the various structural parameters of the optical fiber SPR sensor on the sensing performance and explores the development of the microfluidic optical fiber SPR biological sensor,and the way of improving its performance.These provide valuable references to the design and optimization of the microfluidic optical fiber SPR sensor and its biosensing applications.