Surface plasmon resonance sensor sensitivity enhancement using gold-dielectric material

Abstract

There has been increasing interest in the field of surface plasmon resonance sensing technology according to its advantages such as the small amount of sensing samples required, freedom of electromagnetic interference and greater sensitivity. This research investigates the using of a thin layer of dielectric material such as Barium Titanate (BaTio₃) over the Gold (Au) layer for enhancing the sensitivity of the surface plasmon resonance sensor based phase interrogation technique. BaTio₃ is adopted due to its excellent dielectric properties such as high dielectric constant and low dielectric loss. Numerical results have demonstrated that the surface plasmon resonance sensor with utilizing a thin layer of the BaTio3 layer (5nm) over a fixed Au layer thickness of (50nm) exhibited a high sensitivity of (250 degree/RIU) among other thickness values of BaTio₃. Contrarily, the comparison of the surface plasmon resonance sensor without utilizing BaTio₃ layer provides (160 degree/RIU) for fixed Au layer thickness (50nm). Hence, using of 5mm thin layer of BaTio₃ over 50nm of Au layer within surface Plasmon layer yield higher sensitivity of 250 (degree/RIU).