Controlled assembly of Fe3O4 magnetic nanoparticles on graphene oxide

We describe a facile approach to controllable assembly of mono-disperse Fe3O4 nanoparticles (NPs) on chemically reduced graphene oxide (rGO). First, reduction and functionalization of GO by poly-etheylenimine (PEI) were achieved simultaneously by simply heating the PEI and GO mixture at 60 degrees C for 12 h. The process is environmentally friendly and convenient compared with previously reported methods. Meso-2,3-dimercaptosuccinnic acid (DMSA)-modified Fe3O4 NPs were then conjugated to the PEI moiety which is located on the periphery of the GO sheets via formation of amide bonds between COOH groups of DMSA molecules bound on the surface of the Fe3O4 NPs and amine groups of PEI. The magnetic GO composites were characterized by means of TEM, AFM, UV-vis, FTIR, Raman, TGA, and VSM measurements. Finally, preliminary results of using the Fe3O4-rGO composites for efficient removal of tetracycline, an antibiotic that is often found as a contaminant in the environment, are reported.