Tuning sensitivity of surface plasmon resonance sensor based on ZnO layer and CaF₂ prism for the recognition of SARS-CoV-2

In this work, a Zinc Oxide (ZnO) and Silver (A+) layer with 2D material of graphene layer on a CaF₂ prism is introduced as part of an ultra-high sensitive SPR sensor intended for a modified Kretschmann configuration for the detection of coronavirus SARS-CoV-2 that use angular interrogation. The configuration is highlighted for its substantial contribution to sensitivity enhancement, especially when combined with the low refractive index CaF₂ prism. ZnO is a metal oxide that is particularly interesting because of its unique optical and physical properties. The study optimizes the number (no.) of graphene layers and the thickness of the Ag layer using the transfer matrix method (TMM) to achieve a reflectance curve, a reasonable full width at half maximum (FWHM), and increased sensitivity. A well-optimized structure can produce remarkable results, as noted by numerical results showing a sensitivity of up to 364.17◦/RIU with remarkable figure of merit (FoM). Based on its outstanding performance in future scope, the proposed sensor is suitable for sensing applications in the industrial and biomedical fields.