| Abstrak/Abstract |
The objective of this research is to advance the affectability of Surface Plasmon Resonance
(SPR) biosensor utilizing core-shell Fe3O4@Ag nanoparticles (Fe3O4@Ag NPs) with a variation of
Ag concentration (20, 40, 60, 80, 100) mM. Fe3O4@Ag NPs were synthesized by the aqueous solution
method. The characterization by utilizing X-ray Diffractometer (XRD) depicts that the crystal
structure of Fe3O4 compares to the cubic inverse spinel structure and based on Transmission Electron
Microscopy (TEM) estimation, the particle size average of Fe3O4@Ag NPs is 14.45 nm. The
magnetic properties of Fe3O4@Ag NPs were evaluated by Vibrating Sample Magnetometer (VSM),
the result appears that the more concentration of Ag increases, the more remanent magnetization (Mr),
saturation magnetization (Ms), and coercitivity field (Hc) diminishes. In this research, a Fe3O4@Ag
NPs, a spherical nanoparticle consisting of a spherical Fe3O4 core covered by an Ag shell, was used
as an active material to enhance the signal detection of SPR, with a wavelength of 632.8 nm in the
Kretschmann configuration. The system consists of a four-layer material, i.e., prism/Au film/
Fe3O4@Ag NPs. The results show that the SPR angle shifted to the larger angle of incident light by
using Fe3O4@Ag NPs. However, the effect of Ag concentration appears that the more concentration
of Ag extends, the lower angle of SPR shifts. The addition of a core-shell in the conventional SPRbased biosensor leads to the enhancement of the SPR biosensor sensitivity if the fractional volume of
the core-shell is large.
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