title: Nanowires enabling signal-enhanced nanoscale Raman spectroscopy.
abstract: Silicon nanowires grown by the vapor-liquid-solid (VLS) mechanism catalyzed by gold show gold caps (droplets) approximately 20-500 nm in diameter with a half spherical towards almost spherical shape. These gold droplets are well suited to exploit the surface-enhanced Raman scattering (SERS) effect and could be used for tip-enhanced Raman spectroscopy (TERS). The gold droplet of a nanowire attached to an atomic force microscopy (AFM) tip could locally enhance the Raman signal and increase the spatial resolution. Used as a SERS template, an ensemble of self-organizing nanowires grown bottom up on a silicon substrate could allow highly sensitive signal-enhanced Raman spectroscopy of materials that show a characteristic Raman signature. A combination of a nanowire-based TERS probe and a nanowire-based SERS substrate promises optimized signal enhancement so that the detection of highly dilute species, even single molecules or single bacteria or DNA strands, and other soft matter is within reach. Potential applications of this novel nanowire-based SERS and TERS solution lie in the fields of biomedical and life sciences, as well as security and solid-state research such as silicon technology.
authors.affiliation: Martin-Luther-University Halle-Wittenberg Hoher Weg 8, 06109 Halle, Germany. mbecker@mpi-halle.mpg.de
authors.forename: Michael
authors.initials: M
authors.lastname: Becker
authors.forename: Vladimir
authors.initials: V
authors.lastname: Sivakov
authors.forename: Ulrich
authors.initials: U
authors.lastname: Gösele
authors.forename: Thomas
authors.initials: T
authors.lastname: Stelzner
authors.forename: Gudrun
authors.initials: G
authors.lastname: Andrä
authors.forename: Hans J
authors.initials: HJ
authors.lastname: Reich
authors.forename: Samuel
authors.initials: S
authors.lastname: Hoffmann
authors.forename: Johannes
authors.initials: J
authors.lastname: Michler
authors.forename: Silke H
authors.initials: SH
authors.lastname: Christiansen
mesh_terms: D003460:Crystallization / Q000379:methods*; D006046:Gold / Q000737:chemistry*; D008422:Materials Testing; D008968:Molecular Conformation; D015336:Molecular Probe Techniques; D036103:Nanotechnology / Q000379:methods*; D043942:Nanotubes / Q000737:chemistry* / Q000648:ultrastructure*; D010316:Particle Size; D013059:Spectrum Analysis, Raman / Q000379:methods*; D013499:Surface Properties
chemical_list: D006046:Gold