Molybdenum Disulfide-based Lossy Mode Resonance Sensors: Uncovering Wider Dynamic Range and High Sensitivity Through Computational Approaches

Until now, Surface Plasmon Resonance (SPR) biosensors still rely on gold as their transducer element, and this makes cheap analytical devices difficult to achieve. On the other hand, lossy mode resonance (LMR) sensors offer transducers with more alternative materials due to their flexibility, which can be excited in p- and s-polarized light. In this research it is carried out a numerical investigation using the transfer matrix method on LMR sensor composed of molybdenum disulfide (MoS₂) as lossy layer and Cytop as matching layer. The reflectance curves for different thicknesses of MoS₂ and Cytop are numerically investigated. The results obtained show that the chip consisting of 250 nm Cytop and 4 layers of MoS₂ has a penetration depth 3 times higher than conventional SPR chips. If sensors with two types of polarization are compared, sensors with s-polarized light have shown higher sensitivity reaching 72.13°/RIU with a wider dynamic range starting from a refractive index of 1.331 to 1.401. In this refractive index range, this sensor has displayed good signal stability where the reduction in resonance dip depth is only ≈6%. These computational results make the proposed structure very promising to be applied in the quantification of biological materials.