The postfunctionalization of polyelectrolyte (PE) poly(vinyl formamide-co-vinylamine) (PVFA-co-PVAm) layers adsorbed on silica or titanium dioxide particles with fullerene (C-60) has been investigated. The functionalization process requires two steps, the adsorption of the (PVFA-co-PVAm) from an aqueous solution onto the inorganic particles (silica or titanium dioxide) and the reaction of the PE-modified particles with C-60 in toluene. By means of this procedure the PVFA-co-PVAm layer on the particle surface is irreversibly fixed by the reaction between the accessible primary amino groups of the PE and fullerene (C-60). The degree of conversion of PVFA-co-PVAm/silica with C-60 has been investigated by UV-vis spectroscopy and quantitative electron paramagnetic resonance spectroscopy, The fixing of only a small amount of fullerene on the PVFA-co-PVAin layer strongly influences the Bronsted acid-base behavior and the surface charge density of the whole particles as shown by electrokinetic measurements. Atomic force microscopic investigations on smooth PVFA-co-PVAm/silicon substrates before and after C-60 functionalization show that C-60 molecules form aggregates within the PE layer. Furthermore, the E-T(30) polarity parameters of the C-60-functionalized PVFA-co-PVAm layers on silica are investigated by various substituted Reichardts dyes.