One-Pot Template-Free Fabrication of Hollow Magnetite Nanospheres and Their Application as Potential Drug Carriers

Monodispersed Fe 3 O 4 nanospheres with hollow interior structures exhibiting high saturation magnetization of 83.0 emu g −1 were fabricated by a facile one-pot route. The fabrication process is very simple with only FeCl 3 ·6H 2 O and anhydrous NaAc as the reactants in an ethylene glycol solution with no templates or surfactants involved. Field-emission scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, and a superconducting quantum interference device magnetometer were used to characterize the morphologies, structures, and properties of the hollow magnetic nanospheres. A plausible mechanism based on oriented attachment and subsequent local Ostwald ripening is proposed. In addition, the experiments of the hollow nanospheres decorated with polyacrylic acids as drug carriers and Rhodamine 6G as a model drug, revealed pH- or salt-responsive release profiles, thus demonstrating the potential of these nanostructures in biomedical applications.