title: Plasmonic circular dichroism of Peptide-functionalized gold nanoparticles.
abstract: Nature is remarkable at tailoring the chirality of different biomolecules to suit specific functions. Chiral molecules can impart optical activity to achiral materials in the form of the particle's electronic transition frequency. Herein, we used peptides of differing secondary structures (random coil and α-helix) to artificially create optically active chiral gold nanoparticles through peptide-nanoparticle interactions as observed by circular dichroism (CD) spectroscopy. This interaction produces a CD signal at the plasmon resonance frequency (∼520 nm) of the chiral peptide-nanoparticle complex. Aggregation of the peptide-coated nanoparticles using metal ions results in a red-shifted plasmonic CD response. Our results suggest that chiroptical properties of nanomaterials can be engineered using peptides.
authors.affiliation: Air Force Research Laboratory, Materials & Manufacturing Directorate, Wright-Patterson Air Force Base, Ohio 45433, USA.
authors.forename: Joseph M
authors.initials: JM
authors.lastname: Slocik
authors.forename: Alexander O
authors.initials: AO
authors.lastname: Govorov
authors.forename: Rajesh R
authors.initials: RR
authors.lastname: Naik
mesh_terms: D002942:Circular Dichroism / Q000379:methods; D003460:Crystallization / Q000379:methods*; D006046:Gold / Q000737:chemistry*; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008968:Molecular Conformation; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure*; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D036103:Nanotechnology / Q000379:methods; D010316:Particle Size; D010455:Peptides / Q000737:chemistry*; D020349:Surface Plasmon Resonance / Q000379:methods; D013499:Surface Properties
chemical_list: D046911:Macromolecular Substances; D010455:Peptides; D006046:Gold