Synthesis and manipulation of high aspect ratio gold nanorods grown directly on surfaces

Here we describe the synthesis of Au nanorods directly on glass surfaces using seed-mediated deposition of Au from AuC1(4)(-) onto surface-attached 3-5 nm diameter Au nanoparticles (AuNPs) in the presence of cetyltrimethylammonium bromide (CTAB). The average length (200 nm to 1.2 mum) and aspect ratio (6-22) of the nanorods increases with increasing AuC1(4)(-) concentration. Short, low aspect ratio Au nanorods are manipulated with an atomic force microscopy (AFM) tip, while longer, high aspect ratio nanorods are bent and broken with the AFM tip.