MoSe2@Zr2CO2 Multilayer heterostructures: boosting SPR for refractive index measurement

In recent years, two-dimensional materials with outstanding chemical stability and bioaffinity have gained significant traction in the field of biosensing. Here, we present a surface plasmon resonance (SPR) sensor based on a two-dimensional MoSe₂@Zr₂CO₂ heterostructure, utilizing the Kretschmann configuration. Through comprehensive simulations, we optimized the structural parameters to enhance sensor performance. Initially, we explored the effect of varying MoSe₂@Zr₂CO₂ layer numbers on SPR wave propagation and identified 16 layers as the optimal configuration for maximizing plasmonic performance. Subsequently, we analyzed the influence of dielectric thickness and refractive index on sensor sensitivity, yielding optimal structural parameters. Finally, we examined the impact of different prism refractive indices on sensor performance, finding that lower refractive index prisms effectively boost sensitivity. Thanks to enhanced light absorption and surface plasmon resonance effects, this sensor exhibits substantial improvements in detecting biomolecules. Compared to conventional SPR sensors employing a 50 nm gold film, the MoSe₂@Zr₂CO₂-based sensor demonstrates an 8-fold increase in the figure of merit (FOM), along with higher sensitivity (92.48°/RIU) and an enhanced FOM (319.63 RIU⁻¹) in the visible spectrum.