title: Photoinduced Electron Transfer within Supramolecular Donor-Acceptor Peptide Nanostructures under Aqueous Conditions.
abstract: We report the synthesis, self-assembly, and electron transfer capabilities of peptide-based electron donor-acceptor molecules and supramolecular nanostructures. These modified peptides contain π-conjugated oligothiophene electron donor cores that are peripherally substituted with naphthalene diimide electron acceptors installed via imidation of site-specific lysine residues. These molecules self-assemble into one-dimensional nanostructures in aqueous media, as shown through steady-state absorption, photoluminescence, and circular dichroism spectra, as well as transmission electron microscopy. Excitation of the oligothiophene donor moieties results in electron transfer to the acceptor units, ultimately creating polar, charge-separated states that persist for over a nanosecond as observed with transient absorption spectroscopy. This study demonstrates how transient electric fields can be engineered into aqueous nanomaterials of biomedical relevance through external, temporally controlled photonic inputs.
authors.affiliation: Department of Chemistry, Krieger School of Arts and Sciences, Johns Hopkins University , 3400 North Charles Street, Baltimore, Maryland 21218, United States.
authors.forename: Allix M
authors.initials: AM
authors.lastname: Sanders
authors.affiliation: Department of Chemistry, Krieger School of Arts and Sciences, Johns Hopkins University , 3400 North Charles Street, Baltimore, Maryland 21218, United States.
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Magnanelli
authors.affiliation: Department of Chemistry, Krieger School of Arts and Sciences, Johns Hopkins University , 3400 North Charles Street, Baltimore, Maryland 21218, United States.
authors.forename: Arthur E
authors.initials: AE
authors.lastname: Bragg
authors.affiliation: Department of Chemistry, Krieger School of Arts and Sciences, Johns Hopkins University , 3400 North Charles Street, Baltimore, Maryland 21218, United States.|Department of Materials Science and Engineering, Whiting School of Engineering, Johns Hopkins University , 3400 North Charles Street, Baltimore, Maryland 21218, United States.|Institute of NanoBioTechnology, Johns Hopkins University , 3400 North Charles Street, Baltimore, Maryland 21218, United States.
authors.forename: John D
authors.initials: JD
authors.lastname: Tovar
mesh_terms: D002942:Circular Dichroism; D004583:Electrons; D006863:Hydrogen-Ion Concentration; D007094:Imides / Q000737:chemistry; D008163:Luminescent Measurements; D046529:Microscopy, Electron, Transmission; D008958:Models, Molecular; D049329:Nanostructures / Q000737:chemistry*; D009281:Naphthalenes / Q000737:chemistry; D010455:Peptides / Q000737:chemistry*; D055668:Photochemical Processes; D013056:Spectrophotometry, Ultraviolet; D013876:Thiophenes / Q000737:chemistry; D014867:Water / Q000737:chemistry
chemical_list: D007094:Imides; D009281:Naphthalenes; D010455:Peptides; D013876:Thiophenes; D014867:Water; C542131:naphthalenediimide