Magnetic core‐shell Fe(3)O(4)@TiO(2) nanocomposites for broad spectrum antibacterial applications

The authors have synthesised a core‐shell Fe(3)O(4)@TiO(2) nanocomposite consisting of Fe(3)O(4) as a magnetic core, and TiO(2) as its external shell. The TiO(2) shell is primarily intended for use as a biocompatible and antimicrobial carrier for drug delivery and possible other applications such as wastewater remediation purposes because of its known antibacterial and photocatalytic properties. The magnetic core enables quick and easy concentration and separation of nanoparticles. The magnetite nanoparticles were synthesized by a hydrothermal route using ferric chloride as a single‐source precursor. The magnetite nanoparticles were then coated with titanium dioxide using titanium butoxide as a precursor. The core‐shell Fe(3)O(4)@TiO(2) nanostructure particles were characterized by XRD, UV spectroscopy, and FT‐IR, TEM, and VSM techniques. The saturation magnetization of Fe(3)O(4) nanoparticles was significantly reduced from 74.2 to 13.7 emu/g after the TiO(2) coating. The antibacterial studies of magnetic nanoparticles and the titania‐coated magnetic nanocomposite were carried out against gram+ve, and gram–ve bacteria (Staphylococcus aureus, Pseudomonas aeruginosa, Shigella flexneri , Escherichia coli, and Salmonella typhi) using well diffusion technique. The inhibition zone for E. coli (17 mm after 24 h) was higher than the other bacterial strains; nevertheless, both the uncoated and TiO(2)‐coated magnetite nanocomposites showed admirable antibacterial activity against each of the above bacterial strains.