Simulation design: The gold-bismuth bi-layer surface plasmon resonance for a biosensor.

The Surface Plasmon Resonance (SPR) mechanism used to design a biosensor and sensitive optical sensor for different applications. This work used Matlab software to simulate and analyze SPR with gold layer thickness (40 nm) and Bismuth (Bi) layer at different eight thicknesses (from 10 to 80 nm). These layers were deposited on N_LASF9 glass prism, while the final sensing medium is the air. The analysis achieved for different wavelengths in the visible band (500-700 nm) and different refractive index (0, 0.04, 0.08 and 0.12). The properties of SPR angle (θ_SPR) are extracted from the incident angle θ_incid plot diagram. The sensitivity (S) of the suggested system is calculated within this study. The results show that the maximum sensitivity is (95.5) for thickness (20 and 30 nm) of Bi, and Δn= 0.04 at wavelength 700nm. The best sensitivity is 90 at wavelength 600 nm for thickness 40 nm for the studied refractive index. [ABSTRACT FROM AUTHOR]