A Numerical Analysis for the Detection of Water Salinity Concentration Using Long-Range Surface Plasmon Resonance Biosensor With TMDCs-Teflon/Cytop

A novel approach is suggested to enhance imaging sensitivity and refine the figure of merit (FoM) through the utilization of a long-range surface plasmon resonance (LRSPR) biosensor for the detection of water salinity concentration. This design integrates Teflon, copper (Cu), and a transition metal dichalcogenides (TMDCs) layer. By incorporating this composite coating, the biosensor aims to inhibit oxidation, boost biomolecule adsorption, and elevate imaging sensitivity, detection accuracy (DA), and FoM. Using MoS2, MoSe2, WS2, and WSe2 with the Teflon layer, the maximum achieved imaging sensitivities are 27651/RIU, 26501/RIU, 28059/RIU, 27209/RIU at 0% and 33245/RIU, 31458/RIU, 32424/RIU, 30472/RIU at 30%, water salinity concentration, respectively. Further, with the TMDCs layer, the maximum attained DA and FoM values with MoS2 are 33.33/° and 519.13/RIU, with MoSe2 are 50/° and 758.2/RIU, with WS2 are 50/° and 713.12/RIU, and with WSe2 are 50/° and 725.41/RIU, respectively. Additionally, the penetration depth (PD) of 566.12, 566.24, 493.77, and 508.3 nm at 0% and 700.14, 624.35, 570.28, and 569.94 nm at 30% salinity concentration is achieved. The numerical findings are compared to Teflon/Cytop layer-based LRSPR and conventional SPR (cSPR) sensors. We believe that this approach will have valuable applications in biological detection, medical diagnostics, and chemical analysis. While this work is solely based on simulations, we plan to conduct experimental studies in subsequent phases to further validate and refine the obtained numerical results.