Research On Silanized Fiber Surface Plasmon Resonance Sensor

The traditional fiber surface plasmon resonance(SPR)sensor is mainly composed of three parts,namely the light source,the sensing area and the spectrometer.The sensing area is the core component of the sensor,but all fiber-optic SPR sensing areas face a common problem,that is,the coupling problem between the core and the metal layer that produces the SPR effect.Since the main component of the core is SiO2,the chemical adhesion between the metal layer and the core is not good.Therefore,chromium,titanium and the like are mostly used as adhesives between the metal layer and the core.It will affect the SPR and reduce the sensitivity of the sensor.The so-called silanization is the treatment of a specific sample surface by using an organic silane aqueous solution.The significance of silanization of optical fiber is that some silanization reagents can be used outside the core to modify the chemical group with good binding with the metal layer,which improves the robustness and does not affect the sensor sensitivityIn this paper,silanization technology is introduced into the optical fiber SPR sensor as an adhesion layer,the related preparation process is tested,and the corresponding sensing system is designed and improved.The combination between the metal film and the optical fiber core is improved,and the sensing performance of the sensor is guaranteed.The main research contents of this article include1.Introduced the optical fiber SPR sensing technology and the principle of silanization technology,and expounded the related development process and current research status at home and abroad.It shows the main research content and significance of this paper2.Silanization technology is introduced into the optical fiber SPR sensing,and a four-layer structure of core-silanization layer-metal layer-medium to be measured using a silylation layer as an adhesion layer is proposed.The formula and simulation method for calculating its reflection coefficient are given.This paper introduces three main indicators of SPR sensor performance:full width at half maximum,sensitivity,and quality factor3.Compare the effects of different adhesion layers on the performance of fiber optic SPR sensors.The simulation models of chromium layer,titanium layer and silanized layer were established respectively,and the influence of three adhesion layers on the sensor was analyzed from the perspective of performance indicators.On this basis,the superiority of the silylation layer is highlighted.The effect of silanized layer was verified by experimental means.At the same time,the influence of three system parameters on the selection of the metal layer,the thickness of the metal layer,and the length of the sensing area on the performance of the silylated optical fiber SPR sensor is studied4.The preparation technology of silylated fiber SPR sensor probe is studied.Using multimode optical fiber as the material,using MPTMS reagent,hydrofluoric acid,ion sputtering instrument,etc.,the three steps of optical fiber cladding,core silanization,and core gold plating were completed.An optical fiber SPR sensing probe with a silylation layer was prepared.5.Two silanized fiber SPR sensing systems are designed.The first designed system is an accurate measurement type,which uses an on-line transmission structure,using silylated single-mode fiber as the sensing area,and gives the system specific measurement method Considering the service life and system performance,the sensitivity can reach 6555nm/RIU in the detection range of 1.33-1.42RIU.The second system is a position calibration type,which uses a terminal reflection structure and uses a silylated multimode fiber as the sensing area.The up-conversion luminous particles are modified outside the sensing area,and the function of calibrating the measurement position is added.In the detection range of 1.33-1.42 RIU,the sensitivity can reach 5010nm/RIU.