title: Enhancement of low-energy electron emission in 2D radioactive films.
abstract: High-energy radiation has been used for decades; however, the role of low-energy electrons created during irradiation has only recently begun to be appreciated. Low-energy electrons are the most important component of radiation damage in biological environments because they have subcellular ranges, interact destructively with chemical bonds, and are the most abundant product of ionizing particles in tissue. However, methods for generating them locally without external stimulation do not exist. Here, we synthesize one-atom-thick films of the radioactive isotope (125)I on gold that are stable under ambient conditions. Scanning tunnelling microscopy, supported by electronic structure simulations, allows us to directly observe nuclear transmutation of individual (125)I atoms into (125)Te, and explain the surprising stability of the 2D film as it underwent radioactive decay. The metal interface geometry induces a 600% amplification of low-energy electron emission (<10 eV; ref. ) compared with atomic (125)I. This enhancement of biologically active low-energy electrons might offer a new direction for highly targeted nanoparticle therapies.
authors.affiliation: Department of Chemistry, Tufts University, 62 Talbot Avenue Medford, Massachusetts 02155, USA.
authors.forename: Alex
authors.initials: A
authors.lastname: Pronschinske
authors.affiliation: Thomas Young Centre, London Centre for Nanotechnology and Department of Chemistry, University College London, London WC1E 6BT, UK.
authors.forename: Philipp
authors.initials: P
authors.lastname: Pedevilla
authors.affiliation: Department of Chemistry, Tufts University, 62 Talbot Avenue Medford, Massachusetts 02155, USA.
authors.forename: Colin J
authors.initials: CJ
authors.lastname: Murphy
authors.affiliation: Department of Chemistry, Tufts University, 62 Talbot Avenue Medford, Massachusetts 02155, USA.
authors.forename: Emily A
authors.initials: EA
authors.lastname: Lewis
authors.affiliation: Department of Chemistry, Tufts University, 62 Talbot Avenue Medford, Massachusetts 02155, USA.
authors.forename: Felicia R
authors.initials: FR
authors.lastname: Lucci
authors.affiliation: PerkinElmer, Inc., 331 Treble Cove Road North Billerica, Massachusetts 01862, USA.
authors.forename: Garth
authors.initials: G
authors.lastname: Brown
authors.affiliation: PerkinElmer, Inc., 331 Treble Cove Road North Billerica, Massachusetts 01862, USA.
authors.forename: George
authors.initials: G
authors.lastname: Pappas
authors.affiliation: Thomas Young Centre, London Centre for Nanotechnology and Department of Chemistry, University College London, London WC1E 6BT, UK.
authors.forename: Angelos
authors.initials: A
authors.lastname: Michaelides
authors.affiliation: Department of Chemistry, Tufts University, 62 Talbot Avenue Medford, Massachusetts 02155, USA.
authors.forename: E Charles H
authors.initials: EC
authors.lastname: Sykes
mesh_terms: D001610:Beta Particles; D004583:Electrons; D006046:Gold / Q000737:chemistry*; D007456:Iodine Isotopes / Q000737:chemistry; D008567:Membranes, Artificial
chemical_list: D007456:Iodine Isotopes; D008567:Membranes, Artificial; D006046:Gold