Nanoscale chemical patterns on gold microplates

To generate nanoscale biochemical patterns for fundamental biophysical studies as well as practical biosensors, there remains a need for a high quality and versatile substrate. We show that chemically synthesized gold microplates on indium tin oxide are an ideal substrate that combines several desirable characteristics, including low cost, single crystallinity, optical transparency, electrical conductivity, and ease in chemical functionalization. We have developed a convenient one-pot method that allows us to synthesize plates of desired dimensions and surface coverage directly on indium tin oxide. We have used electrochemical desorption to strip the capping agents, allowing reliable functionalization with alkanethiol self-assembled monolayers. These plates can serve as nanoscale "lab benches" that allow high-resolution scanning probe lithography, high-resolution imaging, and electrical manipulation. Two applications are demonstrated here: nanoshaved self-assembled monolayers (SAMs) on the single crystalline microplates serve as a high-resolution etching resist; AFM nanografting on the plates generates SAM patterns with tailored terminal chemical functionalities.