Dengue has remained a substantial health concern, particularly in regions where it has impacted blood components, including hemoglobin (Hgb), plasma (PLS), and platelets (PLT). Subsequently, extremely sensitive detection instruments have become indispensable. This study has demonstrated a surface plasmon resonance (SPR) biosensor that has been optimized for the detection of dengue through simulations utilizing the finite element method (FEM) and transfer matrix method (TMM). The angular sensitivity and efficacy of the sensor have been improved by the strategic introduction of TiO \( _2 \) and BP layers in the BK7/Ag/TiO \( _2 \) /BP structure. In order to enhance plasmonic performance, an Ag layer is incorporated between the BK7 prism and the plasmonic TiO \( _2 \) layer, in addition to black phosphorus (BP). This layer is designed to enhance sensitivity. This procedure is optimized using MATLAB and COMSOL Multiphysics simulation tools. The outstanding performance metrics that were attained included a sensitivity of 309.742 deg./RIU, a full width at half maximum (FWHM) of 3.5380 deg., a figure of merit (FOM) of 114.176 RIU \( ^{-1} \) , and a quality factor (QF) of 114.3302 RIU \( ^{-1} \) , with a contrast sensitivity factor (CSF) of 16.81 and a differential figure of merit (DFoM) of 6306.210. To enhance sensitivity, additional optimization was implemented, including the modification of dielectric materials, prism types, BP configurations, and layer thicknesses. The biosensor can identify refractive index variations within the biological range of 1.29 to 1.42, suggesting extensive use for disease detection. Its robustness for real-time diagnostics was validated by its strong linear regression, which exhibited an \( R^2 \) of 0.957314. This sophisticated sensor offers a scalable platform for the early detection of dengue and broader biomedical applications.
