Sensitivity enhancement of WS2-coated SPR-based optical fiber biosensor for detecting glucose concentration*

Abstract

In this paper, we propose a theoretical model of the surface plasmon resonance-based optical fiber biosensor for detecting glucose concentration. The Au/ZnO/WS2 multilayer film is coated around optical fiber. Compared with the conventional surface plasmon resonance sensor, WS2 material can increase the sensitivity of the biosensor. The absorption capacity of WS2 is used to load glucose oxidase by forming a sensitive area to recognize glucose. Refractive index of the solution is calculated and then the concentration of the glucose can be obtained by the correspondence between refractive index and glucose concentration. The highest sensitivity of the SPR biosensor with a structure of 40-nm Au/5-nm ZnO/14 layers of WS2 is 4310 nm/RIU. The proposed WS2-based SPR fiber biosensor has a unique effect on the detection of glucose concentration. It is expected to have potential applications in future medical blood glucose concentration detection.