Designing high sensitivity and high figure of merit SPR biosensor using copper and 2D material on CaF2 prism

Abstract

This theoretical work proposed an ultra-high sensitive hybrid structure for modified Kretschmann configuration comprised of copper-2D material layer on CaF2 prism for biosensing applications through angular interrogation method. Here, it is reported that such a configuration in association with the low refractive index CaF2 prism provides major contribution for improving the sensitivity. Using 2D materials in the proposed configuration not only acts as a medium for trapping biomolecules but also protect copper from becoming oxidized. On the basis of transfer matrix method, the thickness of copper layer suitability and the number of 2D layers are optimized to achieve high sensitivity, small FWHM, and minimum reflectance. Numerical results shows that a well optimized structure can achieves outstanding results exhibiting sensitivity as high as 514°/RIU with high FOM as 208.09RIU−1. Hence, copper and well optimized 2D material coated on CaF2 prism can be an excellent approach in sensor design for detecting biomolecules.

Keywords

• Surface plasmon resonance
• Biosensor
• Sensitivity
• CaF2 prism
• Copper
• Black phosphorus