Design and simulation of a graphene-integrated SPR biosensor for malaria detection

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 (Sys₃ and Sys₄) 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. Sys₃ achieved sensitivities of 353.14, 291.14, and 263.26°/RIU, while Sys₄ reached 315.71, 294.81, and 268.65°/RIU, respectively. These values exceed those reported in comparable SPR platforms. Sys₃ showed enhanced optical performance with a higher quality factor and lower detection limit, whereas Sys₄ 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.