This work presents the theoretical design and optimization of a surface plasmon resonance (SPR) biosensor incorporating graphene, silicon nitride, and a thiol-tethered ssDNA layer for malaria detection and stage differentiation. Two configurations (Sys and Sys) were simulated using the transfer matrix method to determine optimal material thicknesses. The final designs were evaluated against three malaria stages-ring, trophozoite, and schizont-based on their refractive index variations. Sys achieved sensitivities of 353.14, 291.14, and 263.26°/RIU, while Sys reached 315.71, 294.81, and 268.65°/RIU, respectively. These values exceed those reported in comparable SPR platforms. Sys showed enhanced optical performance with a higher quality factor and lower detection limit, whereas Sys offered improved biomolecular recognition. Although limited to simulation, the proposed configurations demonstrate potential for label-free, stage-specific malaria diagnostics, supporting future development toward point-of-care applications.