Preparation of gold nanoparticles in formamide and N,N-dimethylformamide in the presence of poly(amidoamine) dendrimers with surface methyl ester groups

Gold nanoparticles were prepared by reduction of HAuCl4 with NaBH4 in the presence of poly(amidoamine)dendrimers with surface methyl ester groups in formamide or N,N-dimethylformamide. Although solutions of HAuCl4 in formamide, in the presence of the dendrimers, were reduced to some extent before reduction, the addition of NaBH4 provided gold nanoparticles whose size decreased with an increase of the dendrimer generation as well as with the concentration of the dendrimers. On the other hand, gold nanoparticles prepared in N,N-dimethylformamide in the presence of the dendrimer were highly monodispersed. In addition, we discussed how the dendrimers acted as templates for the preparation of gold nanoparticles. (C) 2001 Elsevier Science B.V. All rights reserved.