title: Multilayer enhanced gold film over nanostructure surface-enhanced Raman substrates.
abstract: We have developed a novel class of gold multilayer, surface-enhanced Raman scattering (SERS) substrates that are capable of enhancing SERS signals by 15.3-fold over conventional gold film over nanostructure (GFON) SERS substrates, making them comparable in sensitivity to optimized silver film over nanostructure (SFON) substrates, while providing the long-term stability obtained from gold. They are fabricated by depositing 10 A thick silver oxide islands on conventional GFON substrates, followed by deposition of a second continuous gold layer. The silver oxide layer acts as a dielectric spacer between the two continuous gold films and produces significantly enhanced SERS signals, as compared to optimized single layer substrates of the same geometry or comparable substrates prepared by deposition of silver islands that are not oxidized. In addition to the enhanced sensitivity of these multilayer substrates, they also exhibit long SERS active shelf-lives (i.e., months), with no measurable degradation in SERS enhancement, and relative standard deviations in SERS enhancement of less than 5.2% across the substrate's surface.
authors.affiliation: Department of Chemistry and Biochemistry, University of Maryland Baltimore County, 1000 Hilltop Circle, Baltimore, Maryland 21250, USA.
authors.forename: Honggang
authors.initials: H
authors.lastname: Li
authors.forename: Caitlin E
authors.initials: CE
authors.lastname: Baum
authors.forename: Jian
authors.initials: J
authors.lastname: Sun
authors.forename: Brian M
authors.initials: BM
authors.lastname: Cullum
mesh_terms: D020099:Coated Materials, Biocompatible / Q000032:analysis / Q000737:chemistry; D006046:Gold / Q000737:chemistry*; D008422:Materials Testing; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D012822:Silicon Dioxide / Q000737:chemistry*; D013059:Spectrum Analysis, Raman / Q000379:methods*; D013499:Surface Properties
chemical_list: D020099:Coated Materials, Biocompatible; D006046:Gold; D012822:Silicon Dioxide