One-Step Co-Precipitation Synthesis of Water-Stable Poly(Ethylene Glycol)-Coated Magnetite Nanoparticles

Abstract

Magnetite is one of the important materials used in drug delivery systems, magnetic resonance imaging, and cancer therapy due to its low toxicity, durability, high biocompatibility, and low cost. Among the different methods of synthesizing magnetite, co-precipitation presents a facile route for synthesizing nanoparticles. Since rapid crystallization occurs in this method, a coating agent is essential to prevent the aggregation of the nanoparticles and increase its water-stability. In this study, PEG-coated and uncoated magnetite nanoparticles were synthesized by one-step co-precipitation. FeSO4·7H2O, FeCl3·6H2O, and PEG were used as the precursors for the magnetite nanoparticles. Addition of NH4OH while maintaining the reaction in an N2 environment at 80 ° C completed the synthesis of the nanoparticles. XRD analysis confirmed the structure of the synthesized nanoparticles is magnetite. The addition of PEG coating results in generally weaker diffraction peaks as well as the absence of some peaks, indicating a decrease in the crystallinity of the sample. AFM and SEM measurements reveal a spherical morphology for both PEG-coated and uncoated magnetite nanoparticles. DLS measurements showed that the PEG-coated magnetite nanoparticles had a lower average particle diameter (73.95 ± 0.786 nm) compared to that of the uncoated magnetite nanoparticles (143.72 ± 1.60) nm. The observed values are lower compared to the results of a previous study. DLS also showed that both the uncoated and PEG-coated magnetite nanoparticles are monodisperse. Zeta potential analysis reveals that the PEG-coated magnetite nanoparticles are more stable in water than the uncoated magnetite nanoparticles. Addition of the polymer coating reduces the particle size and enhances the water-stability of the magnetite nanoparticles, making it useful for biomedical applications.