Chemoselective Immobilization of Gold Nanoparticles onto Self-Assembled Monolayers

This Letter describes a general method for the immobilization of gold nanoparticles onto solid supports. Ketone-decorated gold colloids are covalently attached to self-assembled monolayers (SAMs) presenting aminooxy groups on a gold surface. The oxime formed by the chemoselective ligation is stable on the film as shown by the cyclic voltammetry of ferrocenecarboxaldehyde immobilized onto aminooxy SAMs. The colloids are characterized by infrared spectroscopy, transmission electron microscopy, and 1H NMR. Tapping mode atomic force microscopy shows that the gold nanoparticles are uniformly distributed on the surface with an average particle diameter of 5.5 nm.