Molecular Recognition-Mediated Fabrication of Protein Nanostructures by Dip-Pen Lithography

We describe the molecular recognition-mediated, stepwise fabrication of patterned protein nanostructures with feature sizes on the order of 200 nm. First, a self-assembled monolayer (SAM) of 16-mercaptohexadecanoic acid (MHA) is patterned onto gold by dip-pen nanolithography (DPN), and the unpatterned regions are passivated with a protein-resistant oligoethylene glycol-terminated alkanethiol SAM. Next, an amine-terminated biotin derivative is covalently conjugated with the chemically activated MHA SAM nanopattern. The surface is then incubated with streptavidin to form streptavidin nanostructures, mediated by molecular recognition between biotin and streptavidin. Finally, protein nanopatterns are fabricated by molecular recognition-mediated immobilization of biotinylated protein from solution. Our fabrication methodology is generically applicable because of the ubiquity of biotin-tagged molecules.