Photoreductive synthesis of water-soluble fluorescent metal nanoclusters.

Water-soluble fluorescent copper, silver and gold nanoclusters with quantum yields of 2.2, 6.8 and 5.3%, respectively, are prepared by a robust photoreduction of their inorganic precursors in the presence of poly (methacrylic acid) functionalized with pentaerythritol tetrakis 3-mercaptopropionate.