Cooperative Self-Assembly of Gold Nanoparticles on the Hydrophobic Surface of Vesicles in Water

Adsorption of gold nanoparticles (NPs) on a hydrophobic fullerene bilayer vesicle ca. 30 nm in diameter occurs through cooperation of vesicle/NP and NP/NP interactions to produce a NP-vesicle hybrid whose surface is uniformly covered with the NPs separated from each other by a few nm. The vesicle coverage by NPs makes the NP-vesicle hybrid unusually stable to withstand high temperature, chromatographic purification, and high salt concentration—conditions too harsh for ordinary self-assembled vesicles, such as lipid vesicles, to survive. The hybrid serves as a platform of chemical reactions; for example, gold-catalyzed reduction of an aromatic nitro group and deposition of gold atoms for in situ growth of the NPs from 3.5 to 7.2 nm in diameter. The robust vesicle structure can be destroyed by the heat produced in interparticle plasmon coupling absorption of a 532 nm laser irradiation.