title: Guided-Mode Resonance Grating with Self-Assembled Silver Nanoparticles for Surface-Enhanced Raman Scattering Spectroscopy.
abstract: We designed and fabricated guided-mode resonance (GMR) gratings on indium-tin-oxide (ITO) thin film to generate a significantly enhanced local electric field for surface-enhanced Raman scattering (SERS) spectroscopy. Ag nanoparticles (NPs) were self-assembled onto the surface of the grating, which can provide a large amount of "hot-spots" for SERS sensing. The ITO gratings also exhibit excellent tolerance to fabrication deviations due to the large refractive index contrast of the ITO grating. Quantitative experimental results of 5,5'-dithiobis(2-nitrobenzoic acid) (DTNB) demonstrate the best enhancement factor of ~14× on ITO gratings when compared with Ag NPs on a flat ITO film, and the limit of detection (LOD) of DTNB is as low as 10 pM.
authors.affiliation: School of Electrical Engineering and Computer Science, Oregon State University, Corvallis, OR 97331, USA.
authors.forename: Jing
authors.initials: J
authors.lastname: Yang
authors.affiliation: School of Electrical Engineering and Computer Science, Oregon State University, Corvallis, OR 97331, USA.
authors.forename: Fanghui
authors.initials: F
authors.lastname: Ren
authors.affiliation: School of Electrical Engineering and Computer Science, Oregon State University, Corvallis, OR 97331, USA.
authors.forename: Xinyuan
authors.initials: X
authors.lastname: Chong
authors.affiliation: Department of Mechanical Engineering, The University of Texas at Austin, Austin, TX 78712, USA; dfan@austin.utexas.edu.
authors.forename: Donglei
authors.initials: D
authors.lastname: Fan
authors.affiliation: Omega Optics, Inc., Austin, Texas 78757, USA; swapnajit.chakravarty@omegaoptics.com.
authors.forename: Swapnajit
authors.initials: S
authors.lastname: Chakravarty
authors.affiliation: Department of Electrical and Computer Engineering, University of Texas at Austin, Austin, TX 78758, USA.
authors.forename: Zheng
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Department of Electrical and Computer Engineering, University of Texas at Austin, Austin, TX 78758, USA.
authors.forename: Ray T
authors.initials: RT
authors.lastname: Chen
authors.affiliation: School of Electrical Engineering and Computer Science, Oregon State University, Corvallis, OR 97331, USA.
authors.forename: Alan X
authors.initials: AX
authors.lastname: Wang
keywords: grating; guided-mode resonance; self-assembling; silver nanoparticles; surface-enhanced Raman scattering