Enhanced Sensitivity of Surface Plasmon Resonance Sensor Based on Bilayers of Silver-Barium Titanate

Surface plasmon resonance (SPR) sensors have been widely adopted with various fields such as physics, chemistry, biology and biochemistry. SPR sensor has many advantages like the less number of sensing samples required, freedom of electromagnetic interference and higher sensitivity. This research investigates the phase interrogation technique of a surface plasmon resonance sensor based on silver and thin film dielectric material of Barium titanate layers. Barium titanate (BaTiO3) layer is adopted due to its excellent dielectric properties such as high dielectric constant and low dielectric loss. The numerical results demonstrate that the fusion of the proposed material BaTiO3 layer into surface plasmon resonance sensor yields a higher sensitivity of 280 degree/RIU in comparison with surface plasmon resonance sensor without BaTiO3 layer which shows only a sensitivity of 120 degree/RIU. As the thickness of this layer increases from 5 nm to 10 nm, the sensitivity is enhanced from 160 degree/RIU to 280 degree/RIU for a fixed metal layer of silver with a thickness of (70 nm).