Location-specific biological functionalization on nanotubes: Attachment of proteins at the ends of nanotubes using Au nanocrystal masks

We developed a novel method to immobilize proteins at a specific location on nanotubes. In this report, avidin was immobilized only at the ends of peptide nanotubes using Au nanocrystals as protective masks on the sidewalls of nanotubes. While the Au nanocrystal-masked nanotubes adsorbed avidin on their entire surfaces, the chemical etching of the Au nanocrystal masks removed avidin molecules from the sidewalls, but avidin at the nanotube ends remained bound. The chemical etching process did not denature avidin and the nanotube ends could recognize and immobilize onto the complimentary biotin SAMs.