Facile synthesis of PEG‐coated magnetite (Fe3O4) and embedment of gold nanoparticle as a nontoxic antimicrobial agent

In the present study, we carried out a chemical synthesis and characterization of Fe₃O₄@PEG‐Au as a core/shell nanocomposite in an aqueous solution by the chemical co‐precipitation of Fe³⁺ and Fe²⁺ ions and encapsulated it by polyethylene glycol (PEG) in order to enhance hydrophilicity and biocompatibility of gold ions and immobilize them in the presence of NaBH₄ as a reducing agent. The nanostructures were characterized with FT‐IR, FESEM, EDS, WDX, VSM, ICP‐MS, and TEM. The antimicrobial activities of the nanostructures were tested against pathogenic microorganisms, including Staphylococcus aureus , Escherichia coli , and Candida albicans by broth microdilution method according to the methods of the Clinical Laboratory Standard Institute (CLSI). The toxicity of the nanostructures was tested against animal cell line based on MTT assay. The synthesized core/shell nanostructures had a good activity against the representative microorganisms of public health concern and revealed an insignificant toxicity against animal cell line.