The Effect of Surface Plasmon Resonances on Spherical Magneto-Plasmonic Fe3O4@Ag Core-Shell Nanoparticles

Abstract

In this work, the scattering, absorption, and extinction cross-sections of 𝐹𝑒3𝑂4@Ag core/shell spherical nanostructures embedded in a dielectric host matrix are investigated theoretically. Electrostatic approximation and Maxwell-Garnet effective medium theory are employed to obtain the effective electric permittivity and magnetic permeability, as well as the corresponding absorption, scattering, and extinction cross-sections. Likewise, for a fixed size of QDs (of radius 𝑎𝑠 = 10 nm) numerical analysis is performed to see the effect of varying the metal fraction (𝛽) and the permittivity (𝜀ℎ) of the host matrix on the magneto-plasmonic nanostructures. The results show that graphs of absorption, scattering, and extinction cross-sections as a function of wavelength have two sets of resonance peaks in the UV and visible regions. These sets of peaks arise due to the strong coupling of the surface plasmon oscillations of silver with the excitonic state of the semiconductor/dielectric at the inner (𝐹𝑒3𝑂4@Ag) and outer (Ag/host) interfaces. The absorption and scattering crosssections are blue-shifted in the first peak and red-shifted for the second set of peaks as 𝛽 increases. Similarly, the extinction cross-section possesses two sets of resonance peaks which are enhanced for an increase in 𝜀ℎ or decrease of 𝛽; keeping one of these two parameters constant at a time. The results obtained may be utilized in applications that incorporates both the plasmonic and magnetic effects in core/shell nanostructures.

Fe3O4 Core–Shell Nanostructures with Anticancer and Antibacterial Properties: A Mini-Review

“…Core-shell nanostructures are defined as heterogeneous nanoparticles composed of two or more nanomaterials that can be identified and are separated by distinct boundaries. Both core and shell components can be inorganic (metals, metal oxides) or organic (polymers, biomolecules) [48][49][50]. Core/shell composite nanostructures (NSs) have attracted much attention in recent years due to their diverse and unique material properties not shown by the core or shell materials alone, such as good mechanical, thermal, and optical properties [48,51].…”

“…Both core and shell components can be inorganic (metals, metal oxides) or organic (polymers, biomolecules) [48][49][50]. Core/shell composite nanostructures (NSs) have attracted much attention in recent years due to their diverse and unique material properties not shown by the core or shell materials alone, such as good mechanical, thermal, and optical properties [48,51]. These properties are significantly enhanced compared to pure compounds [51].…”

“…Silver-coated Fe 3 O 4 nanohybrids have been used in a broad range of applications, including chemical and biological sensors [48,57], drug delivery-as successful drug carriers with focused antimicrobial, anticancer properties [48,58], diagnosis, and cancer therapy [48,59,60].…”

“…It has been discovered that Fe 3 O 4 -Ag nanocomposites present a self-sterilizing property that avoids the formation of biofilms, which are the most dangerous source capable of spreading toxic bacteria into the environment [61], improving the contrast of magnetic resonance imaging (MRI) in cancer detection [48].…”

Synthesis of Silver-Decorated Magnetite Nanoparticles Using Self-Assembly Methods

“…Moreover, the integration of SPIONs with noble metals, such as Pt, Au, and Ag, introduces enhanced functionalities [1,8,9]. AgNPs, known for their antibacterial efficacy and electrical conductivity, are promising candidates for application in wound healing and as conductive materials [10,11].…”