Hybrid Nanoparticles Based on Cobalt Ferrite and Gold: Preparation and Characterization

Abstract

During the past few decades, hybrid nanoparticles (HNPs) based on a magnetic material and gold have attracted interest for applications in catalysis, diagnostics and nanomedicine. In this paper, magnetic CoFe2O4/Au HNPs with an average particle size of 20 nm, decorated with 2 nm gold clusters, were prepared using methionine as a reducer and an anchor between CoFe2O4 and gold. The methionine was used to grow the Au clusters to a solid gold shell (up to 10 gold deposition cycles). The obtained nanoparticles (NPs) were studied by X-Ray diffraction (XRD), transmission electron microscopy (TEM), Fourier-transform infrared (FT-IR) spectroscopy, X-Ray photoelectron spectroscopy (XPS) and UV-vis spectroscopy techniques. The TEM images of the obtained HNPs showed that the surface of cobalt ferrite was covered with gold nanoclusters, the size of which slightly increased with an increase in the number of gold deposition cycles (from 2.12 ± 0.15 nm after 1 cycle to 2.46 ± 0.13 nm after 10 cycles). The density of the Au clusters on the cobalt ferrite surface insignificantly decreased during repeated stages of gold deposition: 21.4 ± 2.7 Au NPs/CoFe2O4 NP after 1 cycle, 19.0 ± 1.2 after 6 cycles and 18.0 ± 1.4 after 10 cycles. The magnetic measurements showed that the obtained HNPs possessed typical ferrimagnetic behavior, which corresponds to that of CoFe2O4 nanoparticles. The toxicity evaluation of the synthesized HNPs on Chlorella vulgaris indicated that they can be applied to biomedical applications such as magnetic hyperthermia, photothermal therapy, drug delivery, bioimaging and biosensing.

Copper Ferrite Nanoparticles Synthesized Using Anion Exchange Resin: Influence of Synthesis Parameters on the Cubic Phase Stability

“…So in this case the most stable colloidal system is formed and particles with a minimum size are produced [23,35]. These results were similar to our previous study, where CoFe2O4 nanoparticles with a size of 15 nm were obtained in the presence of dextran-40 [36].…”

Au-Loaded Superparamagnetic Mesoporous Bimetallic CoFeB Nanovehicles for Sensitive Autoantibody Detection

“…Fe and Co have a higher magnetic moment than Ni, affording them superior superparamagnetic properties; therefore, extensive efforts have been devoted to synthesizing CoFe-based compounds. − Additionally, introducing Fe into Co-based nanomaterials can alter the chemical properties of Co via electronic interactions between Co and Fe (alloying effect). , Although magnetic CoFe-based MN compounds have been reported, − these materials still possess limitations. For example, most reported CoFe-based compounds are metal oxides, such as CoFe 2 O 4 − or CoFeO x , which usually exhibit a lower saturation magnetization ( M S ) than their metallic state, and these inert oxides are unsuitable for further functionalization.…”

Innovative Gold/Cobalt Ferrite Nanocomposite: Physicochemical and Cytotoxicity Properties

“…The combination of magnetic and high photothermal conversion properties [12,13] can be achieved by combining gold and CFO nanoparticles in a form of core/shell [14,15] or cluster structures [16,17]. In literature, there are only two main approaches for Au and CFO nanoparticles' composite fabrication.…”

“…The first is the deposition of gold species onto the CFO nanoparticles by one-pot gold reduction from chloroauric acid (HAuCl 4 ) solution, forming a core/shell structure [18]. The second is the adsorption of gold seeds/nanoparticles on the surface of CFO, forming clusters of gold nanoparticles on a surface of magnetic nanoparticles [17,19]. However, both synthesis methods are complicated and require precise control of nanoparticles' growth.…”

“…However, both synthesis methods are complicated and require precise control of nanoparticles' growth. One of the solutions may lay in a separate synthesis of gold and CFO nanoparticles followed with their further combination in a single composite by the means of gold and CFO nanoparticles organic coating [17,20,21].…”