C-60-mediated self-assembly of gold nanoparticles at the liquid/liquid interface in the form of a stable nanocomposite film is repoted. The metallic luster of the interfacial film results from the electronic coupling of Au nanoparticles, suggesting the formation of closely packed nanoparticle thin C films. The interfacial film of nanoparticles could be transferred to mica substrates and carbon-coated transmission electron microscopy (TEM) grids, and then studied by UV-vis, Raman spectroscopy and TEM. (c) 2005 Elsevier B.V. All rights reserved.