Luminescent Silver Clusters with Covalent Functionalization of Graphene

Brightly luminescent, atomically precise sub-nanometer clusters of silver protected by glutathione were covalently functionalized by solution phase thiolated graphene using ligand exchange. A hybrid molecule was formed, which was obtained in a nearly pure form by phase transfer from the aqueous to the organic phase. The resulting hybrid exhibited properties of both of these nanoscale materials. UV-vis, luminescence, XPS, EDAX, TEM, and Raman spectroscopy were used to characterize the hybrid structure, which showed the spectroscopic characteristics of both the constituents. The luminescence of the cluster was retained in the hybrid, along with features characteristic of graphene. Atomically precise clusters with covalently linked graphene will be useful for new applications in the areas of drug delivery, sensors, and catalysis.