title: Nanosheet Formation by an Anionic Surfactant-like Peptide and Modulation of Self-Assembly through Ionic Complexation.
abstract: The surfactant-like peptide (Ala)6-(Asp) (A6D) is shown to self-assemble into ultrathin (3 nm thick) nanosheets in aqueous solution above a critical aggregation concentration. A combination of circular dichroism and FTIR spectroscopy and X-ray diffraction shows that the nanosheets comprise interdigitated bilayers of the peptide with β-sheet conformation. The self-assembly can be modulated by addition of hexamethylenediamine which is expected to interact with the anionic C terminus (and C-terminal D residue) of the peptide. Multiple ordered nanostructures can be accessed depending on the amount of added diamine. Nanosheet and bicontinuous network structures were observed using cryogenic-TEM and small-angle X-ray scattering. Addition of hexamethylenediamine at a sufficiently large molar ratio leads to disruption of the ordered nanostructure and the formation of a solution of A6D-diamine molecular complexes with highly charged end groups. The multiple acid-functionalized nanostructures that are accessible in this system are expected to have many applications in the fabrication of new nanomaterials.
authors.affiliation: Department of Chemistry, University of Reading, Whiteknights , Reading RG6 6AD, U.K.
authors.forename: Ian W
authors.initials: IW
authors.lastname: Hamley
authors.affiliation: Department of Chemistry, University of Reading, Whiteknights , Reading RG6 6AD, U.K.
authors.forename: Jessica
authors.initials: J
authors.lastname: Hutchinson
authors.affiliation: Department of Chemistry, University of Reading, Whiteknights , Reading RG6 6AD, U.K.
authors.forename: Steven
authors.initials: S
authors.lastname: Kirkham
authors.affiliation: Department of Chemistry, University of Reading, Whiteknights , Reading RG6 6AD, U.K.
authors.forename: Valeria
authors.initials: V
authors.lastname: Castelletto
authors.affiliation: Department of Chemistry, University of Reading, Whiteknights , Reading RG6 6AD, U.K.
authors.forename: Amanpreet
authors.initials: A
authors.lastname: Kaur
authors.affiliation: Department of Applied Physics, Aalto University School of Science , P. O. Box 15100, FI-00076 Aalto, Finland.
authors.forename: Mehedi
authors.initials: M
authors.lastname: Reza
authors.affiliation: Department of Applied Physics, Aalto University School of Science , P. O. Box 15100, FI-00076 Aalto, Finland.
authors.forename: Janne
authors.initials: J
authors.lastname: Ruokolainen