Preparation of fullerene-shell dendrimer-core nanoconjugates

Generation 4 amine-terminated polyamidoamine dendrimer (PAMAM G4) was allowed to react with an excess of buckminsterfullerene (C60) to form a nanoconjugate containing a PAMAM core and C60 shell. The PAMAM-C60 conjugate was characterized by MALDI-TOF, TGA, UV-vis, and IR spectroscopy. Approximately thirty shell fullerenes surround each dendrimer core. The conjugates catalyze photooxidation of thioanisole by generation of singlet oxygen (1O2). The oxidation reactions occur in both organic and aqueous solvents, but the reactivity is enhanced in aqueous solution, possibly due to a nanoreactor effect resulting from diffusion of hydrophobic reactant molecules into dendrimer cavities.