Ultrafine graphene oxide–CoFe2O4 nanoparticle composite as T1 and T2 contrast agent for magnetic resonance imaging

Abstract

Graphene oxide–CoFe₂O₄ nanoparticle composites were synthesized using a two step synthesis method in which graphene oxide was initially synthesized followed by precipitation of CoFe₂O₄ nanoparticles in a reaction mixture containing graphene oxide. Samples were extracted from the reaction mixture at different times at 80 °C. All the extracted samples contained CoFe₂O₄ nanoparticles formed over the graphene oxide. It was observed that the increase in the reflux time significantly increased the saturation magnetization value for the superparamagnetic nanoparticles in the composite. It was also noticed that the size of the nanoparticles increased with increase in the reflux time. Transverse relaxivity of the water protons increased monotonically with increase in the reflux time. Whereas, the longitudinal relaxivity value initially increased and then decreased with the reflux time. Graphene oxide–CoFe₂O₄ nanoparticle composites also exhibit biocompatibility towards the MCF-7 cell line.