Synthesis of fullerenic nanocapsules from bio-molecule carbonisation

There has been great interest in the incorporation of foreign materials int o fullerene structures (C-60, nanotubes, nanoparticles, onions). This inter est has been driven by the potential applications of the filled fullerenes, which lie in areas as diverse as optical, electronic, magnetic recording m aterials and nuclear medicine. In particular, the onion structures of extre me strength may offer excellent protection to their encapsulated nanomateri als for applications. Here, we describe controlled carbonisation of an iron -containing biomolecule, ferritin, at elevated temperatures. This simple te chnique produces macroscopic quantities of quasi-spherical fullerenic shell s (onions) that encapsulate iron nanoparticles of a very narrow range of pa rticle diameters. (C) 2000 Elsevier Science B.V. All rights reserved.