Synthesis of CuFe2O4/Au and CuO/Au Hybrid Gold-Containing Nanoparticles via Anion Exchange Resin-Assisted Precipitation

Hybrid nanoparticles based on nonferrous metal oxides and gold are of interest for application in catalysis and biomedicine, in particular, for magnetic hyperthermia and targeted drug delivery. In this paper, we describe methods for the preparation of oxide (CuO and CuFe₂O₄) cores and hybrid (CuO/Au and CuFe₂O₄/Au) nanoparticles having gold nanoclusters ~2 nm in size on their surface. The hybrid nanoparticles were synthesized using L-methionine, an amino acid that acts as a reducing agent and an “anchor” between the oxide core and gold clusters. The proposed method for the preparation of CuO and CuFe₂O₄ oxide cores—anion exchange resin-assisted precipitation—is simple, fast, and easy to reproduce under ordinary laboratory conditions. It has been shown that anion exchange resin-assisted Cu²⁺ precipitation with no polysaccharide leads to the formation of elongated copper(II) oxide nanoparticles 85 ± 3 nm in length and 15.1 ± 0.3 nm in thickness, whereas anion exchange resin-assisted precipitation of Cu²⁺ and Fe³⁺ in the presence of a polysaccharide (dextran-40) and subsequent heat treatment (850°C) of a stoichiometric precursor yields copper ferrite nanoparticles 18.3 ± 0.4 nm in size. Evaluation of the biocompatibility of all the synthesized materials (CuO, CuFe₂O₄, CuO/Au, and CuFe₂O₄/Au) with the use of Escherichia coli and Bacillus subtilis as test microorganisms has shown that the presence of gold improves their biocompatibility and makes them suitable for biomedical applications.