Synthesis and characterization of peptide nanostructures chemisorbed on gold

Abstract

We report the synthesis and the use of a peptide nanostructure for the preparation of modified gold nanoparticles and gold surfaces. A helical peptide bearing six crown ether side chains, known to form an artificial ion channel, was modified at its termini with biotin and a disulfide group. Using this peptide nanostructure, we were able to prepare gold nanoparticles and self-assembled monolayers on gold surfaces. FTIR and IRRAS experiments demonstrated that the peptide nanostructures retained their helical conformation when chemisorbed on a gold surface and that they are oriented with tilt angles around 55° from the surface normal. AFM studies confirmed that the peptide nanostructures formed well defined and regular surfaces with clusters having average heights of 5–6 nm, in close agreement with the size of the nanostructure.