Practical preparation of anionic mercapto ligand-stabilized gold nanoparticles and their immobilization

Gold nanoparticles stabilized by a water-soluble mercapto ligand (sodium 3-mercaptopropionate) were produced by a modified citrate reduction of HAuCl4. No rigorous cleanliness is needed and the reductant is decomposed to CO2. Stable aqueous dispersions of gold nanoparticles without any precipitation for several months could be obtained. The particle size can be controlled by the stabilizer/gold ratios. These gold nanoparticles were incorporated successfully into the interlayers of cast films of cationic bilayers by immersion of the film in gold nanoparticle dispersions. (C) 1999 Elsevier Science B.V. All rights reserved.