Simulation of surface plasmon resonance (SPR) layers of gold with silicon nitride as a Bi-layer biosensor

Abstract

Surface Plasmon Resonance (SPR) has gotten a lot of attention in biomedical sensing. Many applications in medical diagnostics and single molecule detection have sparked interest in bio-sensing techniques. Surface Plasmon resonance (SPR) is an important phenomenon used for building sensors especially in the Biological fields. Simulation analysis (in Mat lab) has been made for SPR for gold (Au) layer with thickness (40 nm) and layer of silicon nitride (Si3N4) with different thickness (10- 70 nm) step 10, deposited on glass prism type N-LASF9_ glass with the sensitive layer was water at refractive index (Δn = 0, 0.01, 0.05 and 0.1). The analysis was taken for different wavelengths from Ultra-Violet wavelength 100 nm to Near Infra- Red wavelength 1000 nm. The properties of the surface Plasmon resonance angle (θSPR) have been calculated from plotted reflectance against incident angle θincid shows sharper resonance dip, narrower full width half maximum (FWHM), SPR dip length (Ld) increased so that improve in properties SPR and system. The SPR sensitivity (S) was calculated and recorded higher sensitivity about 134.