A Highly Ordered Self-Assembled Monolayer Film of an Azobenzenealkanethiol on Au(111): Electrochemical Properties and Structural Characterization by Synchrotron in-Plane X-ray Diffraction, Atomic Force Microscopy, and Surface-Enhanced Raman Spectroscopy

1995 ◽  
Vol 117 (22) ◽  
pp. 6071-6082 ◽  
Author(s):  
W. Brett Caldwell ◽  
Dean J. Campbell ◽  
Kaimin Chen ◽  
Brian R. Herr ◽  
Chad A. Mirkin ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Surface Enhanced Raman Spectroscopy ◽  
X Ray Diffraction ◽  
Monolayer Film ◽  
Self Assembled Monolayer ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Surface Enhanced ◽  
Surface Enhanced Raman

scholarly journals Formation of Size and Density Controlled Nanostructures by Galvanic Displacement

Nanomaterials ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 644
Author(s):  
Minh Tran ◽  
Sougata Roy ◽  
Steven Kmiec ◽  
Alison Whale ◽  
Steve Martin ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Uniform Density ◽  
X Ray Diffraction ◽  
Galvanic Displacement ◽  
X Ray ◽  
Raman Spectroscopic ◽  
Force Microscopy ◽  
Atomic Force ◽  
Surface Enhanced ◽  
Surface Enhanced Raman

Gold (Au) and copper (Cu)-based nanostructures are of great interest due to their applicability in various areas including catalysis, sensing and optoelectronics. Nanostructures synthesized by the galvanic displacement method often lead to non-uniform density and poor size distribution. Here, density and size-controlled synthesis of Au and Cu-based nanostructures was made possible by galvanic displacement with limited exposure to hydrofluoric (HF) acid and the use of surfactants like L-cysteine (L-Cys) and cetyltrimethylammonium bromide (CTAB). An approach involving cyclic exposure to HF acid regulated the nanostructure density. Further, the use of surfactants generated monodisperse nanoparticles in the initial stages of the deposition with increased density. The characterization of Au and Cu-based nanostructures was performed by scanning electron microscopy, atomic force microscopy, UV-Visible spectroscopy, X-ray photoelectron spectroscopy, Raman spectroscopy and X-ray diffraction. The surface enhanced Raman spectroscopic measurements demonstrated an increase in the Raman intensity by two to three orders of magnitude for analyte molecules like Rhodamine 6G dye and paraoxon.

scholarly journals Plasma Fabrication and SERS Functionality of Gold Crowned Silicon Submicrometer Pillars

Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1244 ◽  
Author(s):  
Paola Pellacani ◽  
Carlo Morasso ◽  
Silvia Picciolini ◽  
Dario Gallach ◽  
Lucia Fornasari ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Surface Enhanced Raman Spectroscopy ◽  
Post Processing ◽  
Advanced Material ◽  
X Ray ◽  
Colloidal Monolayer ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Lift Off ◽  
X Ray Absorption

Sequential plasma processes combined with specific lithographic methods allow for the fabrication of advanced material structures. In the present work, we used self-assembled colloidal monolayers as lithographic structures for the conformation of ordered Si submicrometer pillars by reactive ion etching. We explored different discharge conditions to optimize the Si pillar geometry. Selected structures were further decorated with gold by conventional sputtering, prior to colloidal monolayer lift-off. The resulting structures consist of a gold crown, that is, a cylindrical coating on the edge of the Si pillar and a cavity on top. We analysed the Au structures in terms of electronic properties by using X-ray absorption spectroscopy (XAS) prior to and after post-processing with thermal annealing at 300 °C and/or interaction with a gold etchant solution (KI). The angular dependent analysis of the plasmonic properties was studied with Fourier transformed UV-vis measurements. Certain conditions were selected to perform a surface enhanced Raman spectroscopy (SERS) evaluation of these platforms with two model dyes, prior to confirming the potential interest for a well-resolved analysis of filtered blood plasma.

scholarly journals Fabrication of Bioprobe Self-Assembled on Au–Te Nanoworm Structure for SERS Biosensor

Materials ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3234
Author(s):  
Soo Min Kim ◽  
Taek Lee ◽  
Yeong-Gyu Gil ◽  
Ga Hyeon Kim ◽  
Chulhwan Park ◽  
...  
Keyword(s):  
Surface Enhanced Raman Spectroscopy ◽  
Galvanic Replacement ◽  
Ambient Conditions ◽  
Force Microscopy ◽  
Atomic Force ◽  
Surface Enhanced ◽  
Immunodeficiency Virus ◽  
Surface Enhanced Raman ◽  
Immobilized Substrate ◽  
Interconnected Structure

In the present study, we propose a novel biosensor platform using a gold-tellurium (Au–Te) nanoworm structure through surface-enhanced Raman spectroscopy (SERS). Au–Tenanoworm was synthesized by spontaneous galvanic replacement of sacrificial Te nanorods templated with Au (III) cations under ambient conditions. The fabricated Au–Te nanoworm exhibited an interconnected structure of small spherical nanoparticles and was found to be effective at enhancing Raman scattering. The Au–Te nanoworm-immobilized substrate exhibited the ability to detect thyroxine using an aptamer-tagged DNA three-way junction (3WJ) and glycoprotein 120 (GP120) human immunodeficiency virus (HIV) using an antibody. The modified substrates were investigated by scanning electron microscopy and atomic force microscopy (AFM). The optimal Au–Te nanoworm concentration and immobilization time for the thyroxine biosensor platform were further determined by SERS experimentation. Thus, the present study showed that the Au–Te nanoworm structure could be applied to various biosensor platforms.

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