Research On Phase-sensitive Surface Plasmon Resonance Sensor With High Sensitivity

Surface plasmon resonance(SPR)sensor is a precise optical sensing device that is capable of performing real-time,label-free,and high-sensitivity monitoring of molecular interactions.SPR sensors can be divided according to their operating principles into intensity,angular,wavelength and phase interrogation,among which phase interrogation sensor has the highest sensitivity and it normally used for detection of small biomolecules and ultra-low concentrations.While,scientific research is endless,people have been pursuing higher detection sensitivity and resolution.Improving sensitivity of phase interrogation SPR sensor is always a research hotspot.This thesis,based on the phase interrogation SPR sensor,improves detection sensitivity of a sensor by means of a novel sensing structure as well as a new measuring method.To be specific,this thesis consists of following parts:1.Principle and review of SPR sensor.In the first chapter,we introduce principle,feature and history of SPR sensors with respect to the four types.In the next chapter,we prove the existence of SPW theoretically and we get the requirement of SPR.2.Design of a novel high sensitive phase interrogation SPR sensor.We propose a novel design based on graphene and bimetallic structure.In the third chapter,we build up theoretical models for the structure and optimize each parameter regarding to detection sensitivity.3.Techniques for fabricating SPR microfluidic chips and transferring graphene layers.As an essential part in SPR sensor,we describe the process of fabricating several microfluidic chips in the forth chapter.What's more,the method of transferring graphene layers is also explored in preparation of graphene based sensors.4.Goos-Hanchen shift measurement system.The principle of SPR enhanced GH shift is studied theoretically.We utilize the GH shift to replace phase change as the sensing signal.The GH shift is measured with a lab-built system which is much simpler than a phase interrogation system.Sensitivity as high as 8.02×10-7 RIU is achieved in a NaCl solution experiment.