Functionalization of carbon encapsulated iron nanoparticles

Carbon-encapsulated magnetic nanoparticles are a new class of materials where the core magnetic nanoparticle is protected from reactions with its environment by graphite shells. Having a structure similar to carbon nanotubes, these nanoparticles could be potentially functionalized using methods which are already applied to those structures. We present the effects of acidic treatments based on HCl, HNO₃, and H₂SO₄ on these nanoparticles highlighting the impact on their magnetic and surface properties. We show that acidic treatments based on HNO₃ can be successfully applied for the generation of carboxylic groups on the surface of the nanoparticles. Using methylamine as a model, we demonstrate that these functional groups can be used for further functionalization with amino-containing biomolecules via diimide-activated amidation.