title: A chemical route to increase hot spots on silver nanowires for surface-enhanced Raman spectroscopy application.
abstract: The effective number of surface-enhanced Raman spectroscopy (SERS) active hot spots on plasmonic nanostructures is the most crucial factor in ensuring high sensitivity in SERS sensing platform. Here we demonstrate a chemical etching method to increase the surface roughness of one-dimensional Ag nanowires, targeted at creating more SERS active hot spots along Ag nanowire's longitudinal axis for increased SERS detection sensitivity. Silver nanowires were first synthesized by the conventional polyol method and then subjected to chemical etching by NH(4)OH and H(2)O(2) mixture. The surfaces of silver nanowires were anisotropically etched off to create miniature "beads on a string" features with increased surface roughness while their crystallinity was preserved. Mapping of single-nanowire SERS measurements showed that the chemical etching method has overcome the limitation of conventional one-dimensional Ag nanowires with limited SERS active area at the tips to produce etched Ag nanowires with an increase in Raman hot spots and polarization-independent SERS signals across tens of micrometers length scale.
authors.affiliation: Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371.
authors.forename: Madeline Shuhua
authors.initials: MS
authors.lastname: Goh
authors.forename: Yih Hong
authors.initials: YH
authors.lastname: Lee
authors.forename: Srikanth
authors.initials: S
authors.lastname: Pedireddy
authors.forename: In Yee
authors.initials: IY
authors.lastname: Phang
authors.forename: Weng Weei
authors.initials: WW
authors.lastname: Tjiu
authors.forename: Joel Min Rui
authors.initials: JM
authors.lastname: Tan
authors.forename: Xing Yi
authors.initials: XY
authors.lastname: Ling
mesh_terms: D053770:Nanowires / Q000737:chemistry*; D012834:Silver / Q000737:chemistry*; D013059:Spectrum Analysis, Raman / Q000379:methods*; D013499:Surface Properties
chemical_list: D012834:Silver