Preparation of helical peptide monolayer-coated gold nanoparticles

We describe herein the preparation of polypeptide (poly(γ-benzyl-l-glutamate)) monolayer-covered gold nanoparticles (PBLG(n)SS-Au). Two types of PBLG(n)SS having PBLG segment length n=20 and 50 were synthesized and successfully attached to the gold nanoparticle surface using the Brust-Schiffern method. The mean sizes of PBLG(n)SS-Au particles and their gold cluster cores in CHCl3, which were evaluated by means of dynamic light scattering and TEM, respectively, demonstrated that the gold cluster surfaces were covered with PBLG monolayers, and their conformation was found to be mainly in α-helix on the basis of FT-IR spectroscopy.