Reversible Nanopatterning on Self-Assembled Monolayers on Gold

The reversible fabrication of positive and negative nanopatterns on 1-hexadecanethiol (HDT) self-assembled monolayers (SAMs) on Au(111) was realized by bias-assisted atomic force microscopy (AFM) nanolithography using an ethanol-ink tip. The formation of positive and negative nanopatterns via the bias-assisted nanolithography depends solely on the polarity of the applied bias, and their writing speeds can reach 800,um/s and go beyond 1000 mu m/s, respectively. The composition of the positive nanopatterns is gold oxide and the nanometer-scale gold oxide can be reduced by ethanol to gold, as proved by X-ray photoelectron spectroscopy (XPS) analysis, forming the negative nanopatterns which can be refilled with HDT to recover the SAMs.