Research On Phase-sensitive Surface Plasmon Resonance Imaging Based Sensor

Surface Plasmon Resonance(SPR)sensing is a high-sensitive optical sensing technique by detecting refractive index changes on the sensing surfaces.It has been widely used in biomedicine,environmental testing and food safety,etc.SPR sensors can be based on intensity-interrogation,angle-interrogation,wavelength-interrogation,phase-interrogation.The sensing resolution of phase-interrogation SPR sensor canreach to 10-7?10-8 RIU,and the it can be easily combined with the SPR imaging technology to achieve multi-array high-throughput SPR phase imaging(SPR-PI)sensing system.This thesis designs and constructsa SPR imaging sensor with high resolution and high throughput based on the microfluidics technology and phase detection.The resolution of the system has been experimentally studied.This thesis consists of the following parts:1.Analysis of SPR principles and summarization of SPR sensor research.This part is presented in chapter 1 and 2.The general status of SPR imaging based sensor is presented in chapter 1,followed with the specific exposition of domestic and foreign researches on phase-sensitive SPR sensor and SPR imaging sensor.Chapter 2 starts from the basic principles of SPR,the propagation equation of the surface plasmon wave is derived based on Maxwell equations and the resonance condition for SPR is also discussed.2.Simulation on optimization analysis of SPR sensor chip structure.Chapter 3 gives the simulation on the optimization of the SPR sensing structure through the Fresnel formula and the transfer matrix method.We have optimized the structure with different thickness of Ag and layer of graphene.To enhance the sensitivity,the structure of Ag-graphene has been chosen.The sensitivity of the optical structure consisting of 45nm Ag thin film and monolayer graphene is 1 or 2 orders of magnitude higher than conventional bare Au-structure.In addition,a Goose-hanchen shift-interrogation is also designed.Its sensitivity can be compared with that of phase-interrogation.However,the detection optical system is simpler and easier to maintain,and data processing is more convenient.3.Traditional technology of micro fluidic chip and industrial chip technology improvement.Chapter 4 mainly introduces the technological fabrication process of microfluidic chip,including the preparation of gold film,PDMS flow-through layer and the chip packaging technology.In addition,we novely design a chip suitable for industrialization,improve the technological process of the traditional chip,and experimentally verify the feasibility of the chip.4.Setup and application of SPR-PI sensing.Chapter 5 mainly introduces the setup and application of SPR-PI system.Combined with the three-prism phase modulation and microfluidic chip,a SPR-PI sensing system is designed.Experimental result shows the detection resolution for sodium chloride solution can get to 10-7 RIU.In addition,angiogenin-antiangiogenin interaction is also demonstrated in the SPR-PI sensing system.