Juharni, Ilyas Maulana Yahya, Edi Suharyadi, Takeshi Kato, Satoshi Iwata
Journal : International Journal of Nanoelectronics and Materials
Vol. 14, January 2021, 209
Abstract
The purpose of this study is to enhance the sensitivity of Surface Plasmon Resonance (SPR) sensor using coreshell Fe3O4@Ag nanoparticles (NPs). Fe3O4@Ag NPs were synthesized by co-precipitation method with various concentration of Ag as a shell. The crsytal structure of Fe3O4 corresponds to the cubic inverse spinel structure. The particle size of Fe3O4@Ag NPs with Ag concentration of 40mM is 13.8 nm. The saturation magnetization (Ms), and coercivity field (Hc) of Fe3O4@Ag NPs with Ag concentration of 20mM is 52.9 emu/g and 157.2 Oe, respectively, and then decreased with the increase of Ag concentration. An intensity of absorption peak increased with the increase of Ag concentration. A spherical nanoparticle consisting of a spherical Fe3O4 core covered by an Ag shell, was used as an active material to increase the signal detection of SPR, with a wavelength of 632.8 nm in the Kretschmann configuration. The system consists of a three-layer materials, i.e., prism/Au/Fe3O4@Ag NPs. The results show that the SPR angle shifted to the larger angle of incident light by using Fe3O4@Ag NPs and the addition of a core-shell in the conventional SPR-based biosensor leads to the enhancement of the SPR biosensor sensitivity.