Polymer-capped gold nanoparticles by ligand-exchange reactions

The thiol-for-DMAP (4-(N,N-dimethylamino) pyridine) exchange-reaction is demonstrated to be very effective in preparing polymer-capped gold nanoparticles. A number of PEO- and PS-capped gold nanoparticles are thus prepared using mild reaction conditions with a minimal amount of excess thiol ligand. Excellent thermal stability, retention of gold core size and morphology as well as very high surface grafting of the polymeric ligand on the gold core are features of this procedure.