title: Fabrication of nano-indented cavities on Au for the detection of chemically-adsorbed DTNB molecular probes through SERS effect.
abstract: Micro/nano-lithographic techniques are usually employed as a straightforward process for roughening a thin-film Au surface for surface-enhanced Raman scattering (SERS). However, a topographical pattern with deepened edges is difficult to control in a rapid and environmental-friendly way. In this study, a simple physical procedure is proposed for tailoring a thin-film Au surface with triangular nanostructures using nano-indentation technique. The as-fabricated nano-indented cavities on Au (nAu) were structured as a characterization substrate for SERS. By calculating the geometries of nAu and the increase of surface area as a function of the concentration of chemically adsorbed 2-nitro-5-thiobenzoic acid (NTB), a combined chemical and electromagnetic effect was estimated. Particularly-made nAu was adjusted for examining chemically adsorbed NTB molecules with differently intensified Raman-active groups by tuning the indentation depth and the tip-to-tip displacement. SERS enhancement factor on a specific NTB/nAu could be increased to 2.1×10(6).
authors.affiliation: Department of Materials Science and Engineering, National Cheng Kung University, No. 1, University Road, Tainan 70101, Taiwan.
authors.forename: Chia-Wei
authors.initials: CW
authors.lastname: Chang
authors.forename: Jiunn-Der
authors.initials: JD
authors.lastname: Liao
authors.forename: Hsien-Chang
authors.initials: HC
authors.lastname: Chang
authors.forename: Li-Kai
authors.initials: LK
authors.lastname: Lin
authors.forename: Yin-Yi
authors.initials: YY
authors.lastname: Lin
authors.forename: Chih-Chiang
authors.initials: CC
authors.lastname: Weng
mesh_terms: D000327:Adsorption; D004228:Dithionitrobenzoic Acid / Q000737:chemistry*; D006046:Gold; D015336:Molecular Probe Techniques; D015335:Molecular Probes / Q000737:chemistry*; D049329:Nanostructures; D013059:Spectrum Analysis, Raman / Q000379:methods*; D013439:Sulfhydryl Reagents; D013499:Surface Properties
chemical_list: D015335:Molecular Probes; D013439:Sulfhydryl Reagents; D006046:Gold; D004228:Dithionitrobenzoic Acid