title: Nano- and micro-patterning biotemplated magnetic CoPt arrays.
abstract: Patterned thin-films of magnetic nanoparticles (MNPs) can be used to make: surfaces for manipulating and sorting cells, sensors, 2D spin-ices and high-density data storage devices. Conventional manufacture of patterned magnetic thin-films is not environmentally friendly because it uses high temperatures (hundreds of degrees Celsius) and high vacuum, which requires expensive specialised equipment. To tackle these issues, we have taken inspiration from nature to create environmentally friendly patterns of ferromagnetic CoPt using a biotemplating peptide under mild conditions and simple apparatus. Nano-patterning via interference lithography (IL) and micro-patterning using micro-contact printing (μCP) were used to create a peptide resistant mask onto a gold surface under ambient conditions. We redesigned a biotemplating peptide (CGSGKTHEIHSPLLHK) to self-assemble onto gold surfaces, and mineralised the patterns with CoPt at 18 °C in water. Ferromagnetic CoPt is biotemplated by the immobilised peptides, and the patterned MNPs maintain stable magnetic domains. This bioinspired study offers an ecological route towards developing biotemplated magnetic thin-films for use in applications such as sensing, cell manipulation and data storage.
authors.affiliation: School of Physics and Astronomy, University of Leeds, Woodhouse Lane, Leeds, LS2 9JT, UK and School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, UK. johanna.galloway@bristol.ac.uk.
authors.forename: J M
authors.initials: JM
authors.lastname: Galloway
authors.affiliation: Department of Chemistry, University of Sheffield, Dainton Building, Brook Hill, S3 7HF, UK.
authors.forename: S M
authors.initials: SM
authors.lastname: Bird
authors.affiliation: School of Computer Science, University of Manchester, Kilburn Building, Oxford Road, Manchester, M13 9PL, UK.
authors.forename: J E
authors.initials: JE
authors.lastname: Talbot
authors.affiliation: School of Physics and Astronomy, University of Leeds, Woodhouse Lane, Leeds, LS2 9JT, UK.
authors.forename: P M
authors.initials: PM
authors.lastname: Shepley
authors.affiliation: Department of Materials Science and Engineering, University of Sheffield, Sir Robert Hadfield Building, Maplin Street, Sheffield, S1 3JD, UK.
authors.forename: R C
authors.initials: RC
authors.lastname: Bradley
authors.affiliation: Department of Chemistry, University of Sheffield, Dainton Building, Brook Hill, S3 7HF, UK and School of Chemistry, University of Newcastle, Chemical Nanoscience Laboratories, Bedson Building, Newcastle Upon Tyne, NE1 7RU, UK.
authors.forename: O
authors.initials: O
authors.lastname: El-Zubir
authors.affiliation: Department of Materials Science and Engineering, University of Sheffield, Sir Robert Hadfield Building, Maplin Street, Sheffield, S1 3JD, UK.
authors.forename: D A
authors.initials: DA
authors.lastname: Allwood
authors.affiliation: Department of Chemistry, University of Sheffield, Dainton Building, Brook Hill, S3 7HF, UK.
authors.forename: G J
authors.initials: GJ
authors.lastname: Leggett
authors.affiliation: School of Computer Science, University of Manchester, Kilburn Building, Oxford Road, Manchester, M13 9PL, UK.
authors.forename: J J
authors.initials: JJ
authors.lastname: Miles
authors.affiliation: Department of Chemistry, University of Sheffield, Dainton Building, Brook Hill, S3 7HF, UK.
authors.forename: S S
authors.initials: SS
authors.lastname: Staniland
authors.affiliation: School of Physics and Astronomy, University of Leeds, Woodhouse Lane, Leeds, LS2 9JT, UK.
authors.forename: K
authors.initials: K
authors.lastname: Critchley
mesh_terms: D006046:Gold; D055767:Immobilized Proteins / Q000737:chemistry; D008280:Magnetics; D053758:Nanoparticles / Q000737:chemistry*; D010455:Peptides / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D055767:Immobilized Proteins; D010455:Peptides; D006046:Gold