Ultrasmall superparamagnetic Fe₃O₄ nanoparticles: honey-based green and facile synthesis and in vitro viability assay

In the present research, we report a quick and green synthesis of magnetite nanoparticles (Fe₃O₄-NPs) in aqueous solution using ferric and ferrous chloride, with different percentages of natural honey (0.5%, 1.0%, 3.0% and 5.0% w/v) as the precursors, stabilizer, reducing and capping agent, respectively. The effect of the stabilizer on the magnetic properties and size of Fe₃O₄-NPs was also studied.

The nanoparticles were characterized by X-ray diffraction (XRD) analysis, field emission scanning electron microscopy, energy dispersive X-ray fluorescence, transmission electron microscopy (TEM), vibrating sample magnetometry (VSM) and Fourier transform infrared spectroscopy.

The XRD analysis indicated the presence of pure Fe₃O₄-NPs while the TEM images indicated that the Fe₃O₄-NPs are spherical with a diameter range between 3.21 and 2.22 nm. The VSM study demonstrated that the magnetic properties were enhanced with the decrease in the percentage of honey. In vitro viability evaluation of Fe₃O₄-NPs performed by using the MTT assay on the WEHI164 cells demonstrated no significant toxicity in higher concentration up to 140.0 ppm, which allows them to be used in some biological applications such as drug delivery.

The presented synthesis method can be used for the controlled synthesis of Fe₃O₄-NPs, which could be found to be important in applications in biotechnology, biosensor and biomedicine, magnetic resonance imaging and catalysis.