Surface plasmon resonance simulating technology as a bio-sensors
摘要
Plasmon’s surface polarizations (SPPS) are excited through a prism and are highly dependent on the incident light polarization, the complex refractive index of the metal, the thickness of the metal layer, the optical properties of the dielectric material, and the angle at which the light beam incident. This study measures the plasmonic activity of the change in gold thickness (Au) and tin selenide (SnSe) at different wavelengths, displaying a range of boundaries from UV to near infrared. Plasmon resonance on the surface, or SPR, is an important phenomenon that is especially helpful for creating sensors in the biological domains. Matlab has been used to model the SPR for the SnSe layer with variable thickness (10–80 nm) and the gold (Au) layer with fixed thickness (50 nm) with step 10. Using water as the sensitive medium and a refractive index of 0 and 0.01, the layers were placed on glass prism type BK7_glass.The analysis was performed at a variety of wavelengths, from the ultraviolet (300 nm) to the near infrared (1000 nm), with a step size of 100 nm. Calculating the characteristics of the surface plasmon resonance angle (θSPR) by plotting reflectance against incidence angle has shown improved SPR and system properties such a sharper resonance dip, narrower full width half maximum (FWHM), and enhanced SPR dip length (Ld). With Ld = 0.947° and FWHM = 5.6°, the SPR sensitivity (S) was computed and found to be higher at around 240 at dSnSe 80 nm. Since SPR is visible at all SnSe layer thicknesses (0–80 nm), with the best thicknesses occurring at 50–80 nm, the suggested SPR sensor can detect even the smallest variations in the sensing medium's refractive index.