The effect of Zn2+ ion substitution on nanoparticles of ZnxMn(1-X) Fe2O4 (X = 0.2, 0.4, 0.6, 0.8) towards signal surface plasmon resonance (SPR)

Abstract

ABSTRACT This study examined the effect of Zn2+ ion substitution on ZnxMn(1-x) Fe2O4 nanoparticles (x = 0.2, 0.4, 0.6, 0.8) towards signal Surface Plasmon Resonance (SPR). The co-precipitation method synthesised the nanoparticles at a temperature of 90°C. The X-Ray Diffraction (XRD) results showed a polycrystalline structure with a crystallite size varied from 19.05 nm to 19.77 nm. In addition, as the Zn element increased in the ZnxMn(1-x)Fe2O4 nanoparticles, the degree of crystallinity increased by 21.72%, respectively. The optical properties of the nanoparticles ZnxMn(1-x) Fe2O4 indicate absorbance at wavelengths of 330.36–331.74 nm. The absorbance level increased as the Zn element decreased, resulting a direct optical gap of 3.47 eV and an indirect optical gap of 3.23 eV. The Attenuated Total Reflection (ATR) curve in the SPR biosensor indicated a shift in the reflective angle of the Prism/Au/Air configuration, which is 47.78° on Prisma/Au/nanoparticle of Zn0.8Mn0.2Fe2O4/air by 50.75°, and the prism/Au/nanoparticle of Zn0.2Mn0.8Fe2 O4/air by 51.04°. The substitution of Zn ions in the compound Zn x Mn(1-x)Fe2O4 affects the resulting ATR curve. The shift in the SPR angle is caused by changes in the refractive index in each layer which is influenced by the concentration of each material which has an impact on the absorbance ability and photon reflectance. This research has the potential to continue with the testing of dielectric and magnetic properties, as well as special testing for biological analytes compatible with ZnxMn(1-x)Fe2O4 nanoparticles.