Au "ink" for AFM "dip-pen" nanolithography

Scanning probe lithography is a rapidly growing research field, in which atomic force microscope based "dip-pen" nanolithography (DPN)is a simple new technique for creating chemically distinct nanostructures on surfaces in a "direct-write" fashion. Previous works demonstrate the transport of alkanethiols to a gold substrate, resulting in the formation of patterned self-assembled monolayers. Here, we show that surface-induced reduction of metal ions combined with DPN can be used to create metallic nanostructures on Si surfaces. Au nanostructures with sub-100-nm resolution can be created routinely, showing that the DPN technique is a general method for nanofabrication.