title: Chemically and thermally stable silica nanowires with a β-sheet peptide core for bionanotechnology.
abstract: BACKGROUND
  A series of amyloidogenic peptides based on the sequence KFFEAAAKKFFE template the silica precursor, tetraethyl orthosilicate to form silica-nanowires containing a cross-β peptide core.
  
  
  RESULTS
  Investigation of the stability of these fibres reveals that the silica layers protect the silica-nanowires allowing them to maintain their shape and physical and chemical properties after incubation with organic solvents such as 2-propanol, ethanol, and acetonitrile, as well as in a strong acidic solution at pH 1.5. Furthermore, these nanowires were thermally stable in an aqueous solution when heated up to 70 °C, and upon autoclaving. They also preserved their conformation following incubation up to 4 weeks under these harsh conditions, and showed exceptionally high physical stability up to 1000 °C after ageing for 12 months. We show that they maintain their β-sheet peptide core even after harsh treatment by confirming the β-sheet content using Fourier transform infrared spectra. The silica nanowires show significantly higher chemical and thermal stability compared to the unsiliconised fibrils.
  
  
  CONCLUSIONS
  The notable chemical and thermal stability of these silica nanowires points to their potential for use in microelectromechanics processes or fabrication for nanotechnological devices.
authors.affiliation: School of Life Sciences, University of Sussex, East Sussex, Falmer, BN1 9QG, UK.|Chemistry Department, College of Sciences, Al-Mustansyria University, Baghdad, Iraq.
authors.forename: Zahraa S
authors.initials: ZS
authors.lastname: Al-Garawi
authors.affiliation: School of Life Sciences, University of Sussex, East Sussex, Falmer, BN1 9QG, UK.
authors.forename: George E
authors.initials: GE
authors.lastname: Kostakis
authors.affiliation: School of Life Sciences, University of Sussex, East Sussex, Falmer, BN1 9QG, UK. L.C.Serpell@sussex.ac.uk.
authors.forename: Louise C
authors.identifier: http://orcid.org/0000-0001-9335-7751
authors.initials: LC
authors.lastname: Serpell
mesh_terms: D000595:Amino Acid Sequence; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D046529:Microscopy, Electron, Transmission; D053770:Nanowires / Q000737:chemistry* / Q000648:ultrastructure; D010455:Peptides / Q000138:chemical synthesis / Q000737:chemistry*; D000072757:Protein Conformation, beta-Strand; D012822:Silicon Dioxide / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013818:Thermogravimetry
chemical_list: D010455:Peptides; D012822:Silicon Dioxide
keywords: Amyloid fibril; Chemical stability; FTIR; Nanostructures; TGA analysis; Thermal stability; Ultra microtome