Research On Characteristics Of SPR Sensor Based On Two-dimensional Material Sensitization

Surface plasmon resonance can detect small changes in the refractive index of the medium surface environment.Its principle is the phase matching between the evanescent wave and the surface plasmon wave.However,the traditional SPR sensor only has low sensitivity,so it is necessary to design a high-sensitivity SPR biosensor.With the emergence of two-dimensional materials such as graphene,surface plasmon resonance technology has entered a new era,and the sensitivity of sensors has been greatly improved compared to before.Therefore,three SPR biosensors are designed based on two-dimensional materials.Using black phosphorus as the sensitizing layer of surface plasmon resonance,a black phosphorus-based ultra-short side-polished D-shaped photonic crystal fiber surface plasmon resonance(PCF-SPR)biosensor was proposed.The sensor performs short-side polishing on one side of the core cladding while moving the photonic crystal fiber core to the vicinity of the side polishing plane to enhance the interaction between the metal and the medium to be measured.According to the dielectric-metal-dielectric(IMI)structure,the phosphor film is coated on the upper and lower surfaces of the gold film.By comparing the loss spectrum changes with or without black phosphorus,the influence of black phosphorus on the sensitivity of the SPR sensor is analyzed.Due to the weak oxidation resistance of black phosphorus,a graphene-based bimetal PCF-SPR sensor was designed.By replacing the two-dimensional material,graphene is used as the sensitizing material of the sensor,and the sensor uses a bimetallic layer to enhance the sensitivity of the sensor,and the Zn O material solves the oxidation problem of the sensor metal layer.The finite element analysis method is used to analyze the dispersion characteristics of the sensor and the influence of the structural parameters of graphene and Zn O on the sensor.It can be seen from the results that this sensor has the advantages of larger detection range and higher sensitivity compared with the previous sensor.A dual D-type PCF-SPR biosensor based on hexagonal boron nitride is proposed.The base of the sensor is two symmetrical D-type PCF structures.This biosensor mainly uses two methods to enhance sensitivity.One is to enhance the sensitivity of the sensor by designing two double D-type fiber core structures;the other is to form a highly symmetrical zinc oxide-gold-hexagonal boron nitride-test medium-hexagonal boron nitride by coating a two-dimensional material on the metal surface-Gold-Zinc Oxide enhances the sensitivity of the sensor.The results show that the detection range of the sensor is 1.32-1.36,and the average sensitivity of the sensor can reach 6520nm/RIU.In summary,this paper provided a certain reference value for the optimal design of the PCF-SPR biosensor.