Sensitivity enhancement of a bimetallic surface plasmon resonance biosensor

In this study, a plasmonic biosensor with a kreschmann configuration is evaluated by changing the sensing medium's refractive index from 1.330 to 1.335, which includes BK7, gold/silver, silicon, nickel, hexagonal boron nitride, black phosphorus/transition-metal dichalcogenides and sensing medium layers. The sensitivity, figure of merit, quality factor and detection accuracy are the biosensor performance characteristics and are checked at the 633 nm wavelength. The effects of gold and silver layers on the transition-metal dichalcogenides and black phosphorus layers are investigated separately and their performance parameters have been calculated numerically. Since the highest sensitivity is related to the Ag metal with the BP layer, the minimum reflectance and sensitivity as a function of the thickness and number of layers for this structure are examined. The sensitivity of the proposed biosensor (504 deg.RIU -1 ) is approximately 1.5 times higher than the highest sensitivity reported in comparable studies.