Graphene nanoribbons inducing cube-shaped Ag nanoparticle assemblies

Here we report the synthesis of cube-like Ag-nanoparticle (Ag-NP) agglomerates using functionalized graphene nanoribbons (GNR) as templates. The morphology and size of the resulting Ag assemblies are carefully controlled by changing the surface activity of the GNR through chemical functionalization. We propose a mechanism explaining the cube-like organization of the Ag-NP. In particular, the functionalized ribbons first organize in a cubic/rectangular shape, and subsequently thiol moieties preferentially anchor on the edges of the ribbons favoring their surface passivation with Ag-NPs. Furthermore, we found these Ag agglomerates serve as efficient substrate for the Raman detection of 4-aminothiophenol (4-ATP) molecules, through a surface enhancement Raman phenomenon. We believe these novel Ag-NP nanocomposites could also find applications as bactericides, catalysts and electrically conducting fillers.