Size-controlled porous superparamagnetic Zn1/3Fe8/3O4 nanospheres: synthesis, properties and application for drug delivery

Abstract

Magnetic nanospheres have recently attracted much attention in the biomedical areas due to their good biocompatibility and unique magnetic features. Herein we report the synthesis and characterization of different sized porous superparamagnetic iron oxide nanospheres (SPIONs) (Zn_1/3Fe_8/3O₄) which are based on a new rational method of elevated-temperature hydrolysis of chelate iron alkoxide complexes in solutions of the corresponding alcohol, diethyleneglycol (DEG) and diethanolamine (DEA). The size of the SPIONs is controlled by changing the ratio of the reaction media. It is noted that the highly water dispersible porous SPIONs with narrow size distribution can be tuned from 6.5 to 200 nm, each of which is composed of many single magnetite crystallites of approximately 5.5 nm in size. The SPIONs show superparamagnetic properties at room temperature. The superparamagnetic behavior, high magnetization, and high water dispersibility make these nanospheres ideal candidates for various important applications for drug delivery.