title: Optical Actuation of Inorganic/Organic Interfaces: Comparing Peptide-Azobenzene Ligand Reconfiguration on Gold and Silver Nanoparticles.
abstract: Photoresponsive molecules that incorporate peptides capable of material-specific recognition provide a basis for biomolecule-mediated control of the nucleation, growth, organization, and activation of hybrid inorganic/organic nanostructures. These hybrid molecules interact with the inorganic surface through multiple noncovalent interactions which allow reconfiguration in response to optical stimuli. Here, we quantify the binding of azobenzene-peptide conjugates that exhibit optically triggered cis-trans isomerization on Ag surfaces and compare to their behavior on Au. These results demonstrate differences in binding and switching behavior between the Au and Ag surfaces. These molecules can also produce and stabilize Au and Ag nanoparticles in aqueous media where the biointerface can be reproducibly and reversibly switched by optically triggered azobenzene isomerization. Comparisons of switching rates and reversibility on the nanoparticles reveal differences that depend upon whether the azobenzene is attached at the peptide N- or C-terminus, its isomerization state, and the nanoparticle composition. Our integrated experimental and computational investigation shows that the number of ligand anchor sites strongly influences the nanoparticle size. As predicted by our molecular simulations, weaker contact between the hybrid biomolecules and the Ag surface, with fewer anchor residues compared with Au, gives rise to differences in switching kinetics on Ag versus Au. Our findings provide a pathway toward achieving new remotely actuatable nanomaterials for multiple applications from a single system, which remains difficult to achieve using conventional approaches.
authors.affiliation: Institute for Frontier Materials, Deakin University , Geelong, Victoria 3216, Australia.
authors.forename: J Pablo
authors.initials: JP
authors.lastname: Palafox-Hernandez
authors.forename: Chang-Keun
authors.initials: CK
authors.lastname: Lim
authors.affiliation: Department of Chemistry, University of Miami , 1301 Memorial Drive, Coral Gables, Florida 33146, United States.|New Energy Research Institute, School of Environment and Energy, South China University of Technology, Guangzhou Higher Education Mega Centre , Guangzhou, China , 510006.
authors.forename: Zhenghua
authors.initials: Z
authors.lastname: Tang
authors.affiliation: Institute for Frontier Materials, Deakin University , Geelong, Victoria 3216, Australia.
authors.forename: Kurt L M
authors.initials: KL
authors.lastname: Drew
authors.affiliation: Institute for Frontier Materials, Deakin University , Geelong, Victoria 3216, Australia.
authors.forename: Zak E
authors.initials: ZE
authors.lastname: Hughes
authors.affiliation: Department of Chemical and Biological Engineering, University at Buffalo (SUNY) , Buffalo, New York 14260, United States.
authors.forename: Yue
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Chemical and Biological Engineering, University at Buffalo (SUNY) , Buffalo, New York 14260, United States.
authors.forename: Mark T
authors.initials: MT
authors.lastname: Swihart
authors.affiliation: Department of Chemistry, Korea University , Seoul 151-747, Korea.
authors.forename: Paras N
authors.initials: PN
authors.lastname: Prasad
authors.affiliation: Department of Chemistry, University of Miami , 1301 Memorial Drive, Coral Gables, Florida 33146, United States.
authors.forename: Marc R
authors.initials: MR
authors.lastname: Knecht
authors.affiliation: Institute for Frontier Materials, Deakin University , Geelong, Victoria 3216, Australia.
authors.forename: Tiffany R
authors.initials: TR
authors.lastname: Walsh
mesh_terms: D000327:Adsorption; D001391:Azo Compounds / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D007536:Isomerism; D007700:Kinetics; D008024:Ligands; D008027:Light; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D010455:Peptides / Q000737:chemistry*; D058525:Quartz Crystal Microbalance Techniques; D012834:Silver / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet; D013816:Thermodynamics
chemical_list: D001391:Azo Compounds; D008024:Ligands; D010455:Peptides; D012834:Silver; D006046:Gold; C009850:azobenzene
keywords: azobenzene; bionanocombinatorics; conformational switching; nanoparticles; peptides