High enhancement factor gold films for surface enhanced Raman spectroscopy

2003 ◽  
Vol 374 (3-4) ◽  
pp. 302-306 ◽  
Author(s):  
R. Gupta ◽  
W.A. Weimer
Keyword(s):  
Raman Spectroscopy ◽  
Enhancement Factor ◽  
Surface Enhanced Raman Spectroscopy ◽  
Gold Films ◽  
Surface Enhanced ◽  
Surface Enhanced Raman

scholarly journals Optimal Size of Gold Nanoparticles for Surface-Enhanced Raman Spectroscopy under Different Conditions

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Seongmin Hong ◽  
Xiao Li
Keyword(s):  
Gold Nanoparticles ◽  
Raman Spectroscopy ◽  
Enhancement Factor ◽  
Surface Enhanced Raman Spectroscopy ◽  
Total Surface Area ◽  
Optimal Size ◽  
Effective Surface ◽  
Sers Substrates ◽  
Surface Enhanced ◽  
Surface Enhanced Raman

Gold nanoparticles have been used as effective surface-enhanced Raman spectroscopy (SERS) substrates for decades. However, the origin of the enhancement and the effect of the size of nanoparticles still need clarification. Here, gold nanoparticles with different sizes from 17 to 80 nm were synthesized and characterized, and their SERS enhancement toward both 4-aminothiophenol and 4-nitrothiophenol was examined. For the same number of nanoparticles, the enhancement factor generated from the gold nanoparticles increases as the size of nanoparticles increases. Interestingly, when the concentration of gold or the total surface area of gold nanoparticles was kept the same, the optimal size of gold nanoparticles was found out to be around 50 nm when the enhancement factor reached a maximum. The same size effect was observed for both 4-aminothiophenol and 4-nitrothiophenol, which suggests that the conclusions drawn in this study might also be applicable to other adsorbates during SERS measurements.

scholarly journals Surface-Enhanced Raman Spectroscopy on Hybrid Graphene/Gold Substrates near the Percolation Threshold

Nanomaterials ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 164 ◽  
Author(s):  
Dmitry E. Tatarkin ◽  
Dmitry I. Yakubovsky ◽  
Georgy A. Ermolaev ◽  
Yury V. Stebunov ◽  
Artem A. Voronov ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Percolation Threshold ◽  
Surface Enhanced Raman Spectroscopy ◽  
Effective Dielectric Constant ◽  
Gold Films ◽  
Maximum Enhancement ◽  
Sers Signal ◽  
Gold Substrates ◽  
Surface Enhanced ◽  
Surface Enhanced Raman

Graphene is a promising platform for surface-enhanced Raman spectroscopy (SERS)-active substrates, primarily due to the possibility of quenching photoluminescence and fluorescence. Here we study ultrathin gold films near the percolation threshold fabricated by electron-beam deposition on monolayer CVD graphene. The advantages of such hybrid graphene/gold substrates for surface-enhanced Raman spectroscopy are discussed in comparison with conventional substrates without the graphene layer. The percolation threshold is determined by independent measurements of the sheet resistance and effective dielectric constant by spectroscopic ellipsometry. The surface morphology of the ultrathin gold films is analyzed by the use of scanning electron microscopy (SEM) and atomic force microscopy (AFM), and the thicknesses of the films in addition to the quartz-crystal mass-thickness sensor are also measured by AFM. We experimentally demonstrate that the maximum SERS signal is observed near and slightly below the percolation threshold. In this case, the region of maximum enhancement of the SERS signal can be determined using the figure of merit (FOM), which is the ratio of the real and imaginary parts of the effective dielectric permittivity of the films. SERS measurements on hybrid graphene/gold substrates with the dye Crystal Violet show an enhancement factor of ~105 and also demonstrate the ability of graphene to quench photoluminescence by an average of ~60%.

On-Line Spectroscopic Characterization of Sodium Cyanide with Nanostructured Gold Surface-Enhanced Raman Spectroscopy Substrates

2002 ◽  
Vol 56 (12) ◽  
pp. 1524-1530 ◽  
Author(s):  
Peter M. Tessier ◽  
Steven D. Christesen ◽  
Kate K. Ong ◽  
Eva M. Clemente ◽  
Abraham M. Lenhoff ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Surface Enhanced Raman Spectroscopy ◽  
Sodium Cyanide ◽  
Raman Signal ◽  
Gold Films ◽  
Porous Gold ◽  
Wide Range ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
On Line

To implement surface-enhanced Raman spectroscopy as a practical detection method, highly enhancing, stable, and reproducible substrates need to be fabricated in an efficient manner, and their performance in different solution environments should be well characterized. In this work structured porous gold films have been fabricated using colloidal crystals to template gold nanoparticles. These films were integrated into an on-line flow chamber and used to study the effects of pH and other additives on the detection of sodium cyanide. The gold films proved to be highly enhancing and were used to detect cyanide over a wide range of pH values in the concentration range of ∼2 to 200 ppb. The Raman signal intensity could be increased by lowering the pH after the adsorption of cyanide, which was likely due to both a change in the ionization state and a conformational change of the bound molecules. The peak intensity could also be enhanced multifold by treating the substrate with silver nitrate. Cyanide could be removed from the substrates using hydrochloric acid, although this also passivated the structures, and the activity could only be restored partially with tannic acid. These results provide a rational method to optimize the online detection of cyanide in water.

scholarly journals High optical enhancement in Au/Ag alloys and porous Au using Surface-Enhanced Raman spectroscopy technique

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
C. Awada ◽  
C. Dab ◽  
M. G. Grimaldi ◽  
A. Alshoaibi ◽  
F. Ruffino
Keyword(s):  
Raman Spectroscopy ◽  
Enhancement Factor ◽  
Specific Area ◽  
Surface Enhanced Raman Spectroscopy ◽  
Gold Nanostructures ◽  
Localized Surface Plasmon ◽  
Porous Gold ◽  
Alloy Particles ◽  
Surface Enhanced ◽  
Surface Enhanced Raman

AbstractWe report high optical enhancement in Ag/Au alloys and porous gold nanostructures using Surface Enhanced Raman Spectroscopy (SERS) technique. Scanning electron microscopy investigation shows the formation of Ag/Au alloys particles during irradiation of Ag–Au bilayer deposited on FTO (SnO2:F) substrate by laser fluency equal to 0.5 J/cm2 or 1.0 J/cm2 with 12 ns laser pulse duration. The dealloying process of these Au–Ag alloy particles leads to the formation of Au nanoporous particles. The obtained nanostructures were studied with SERS and revealed a promising enhancement factor in porous Au nanostructure and tunability of localized surface plasmon resonance. The highly dense strong hot spots and large specific area in porous structure of gold nanostructures is the origin of the highly enhancement factor observed experimentally and theoretically. A very good agreement between simulation and experimental results was found confirming the potential of Au/Ag alloys and particularly porous gold nanostructure in SERS application.

Plasmonic nanocone arrays for rapid and detailed cell lysate surface enhanced Raman spectroscopy analysis

The Analyst ◽  
2017 ◽  
Vol 142 (23) ◽  
pp. 4422-4430 ◽  
Author(s):  
L. P. Hackett ◽  
L. L. Goddard ◽  
G. L. Liu
Keyword(s):  
Raman Spectroscopy ◽  
Enhancement Factor ◽  
Surface Enhanced Raman Spectroscopy ◽  
Sers Substrate ◽  
Spectroscopy Analysis ◽  
Cell Lysate ◽  
Surface Enhanced ◽  
Surface Enhanced Raman

A plasmonic nanocone SERS substrate with a uniform enhancement factor is developed and applied for cell lysate studies.

scholarly journals Towards a traceable enhancement factor in surface-enhanced Raman spectroscopy

2020 ◽  
Vol 8 (46) ◽  
pp. 16513-16519
Author(s):  
Eleonora Cara ◽  
Luisa Mandrile ◽  
Alessio Sacco ◽  
Andrea M. Giovannozzi ◽  
Andrea M. Rossi ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Surface Density ◽  
Enhancement Factor ◽  
Surface Enhanced Raman Spectroscopy ◽  
Molecular Surface ◽  
X Ray ◽  
Sers Enhancement ◽  
Surface Enhanced ◽  
Surface Enhanced Raman

Determination of the SERS enhancement factor through the challenging measurement of the molecular surface density by reference-free X-ray fluorescence.

Application of Mn–Cu Helical Star-Shaped (Pine-Tree-Like) Sculpted Thin Films with Different Symmetries Using Surface-Enhanced Raman Spectroscopy (SERS)

2019 ◽  
Vol 73 (8) ◽  
pp. 879-892 ◽  
Author(s):  
Hadi Savaloni ◽  
Shokoofe Goli-Haghighi ◽  
Reza Babaei
Keyword(s):  
Thin Films ◽  
Raman Spectroscopy ◽  
Enhancement Factor ◽  
Surface Engineering ◽  
Surface Enhanced Raman Spectroscopy ◽  
Oblique Angle Deposition ◽  
Nano Structure ◽  
Pine Tree ◽  
Surface Enhanced ◽  
Surface Enhanced Raman

In this work, the surface engineering method is used to produce Mn helical star-shaped (pine-tree-like) nanosculptured thin films with three-, four-, and fivefold symmetries on Cu substrates using an oblique angle deposition technique together with rotation of the sample holder at certain angles. Nano structure and morphologies of the produced samples were obtained by means of atomic force microscope and field emission scanning electron microscope. Raman spectroscopy of the Mn/Cu samples impregnated by 4,4′-bipyridine (C10H8N2) solution with different concentrations, zidovudine (C10H13N5O4), and L-histidine (C6H9N3O2) was performed using 532 nm laser wavelength. A high degree of enhancement is achieved on Raman spectroscopy of all of these specimens. Comparison of the surface-enhanced Raman spectroscopy (SERS) results for 4,4′ bipyridine (bipy) obtained in this work with the published literature using Ag and Au substrates in different shapes showed a significant enhancement improvement by using Mn sculptured structures. Reduction of the bipy concentration changed the enhancement factor. Enhancement factors of 107 and 105 were obtained for threefold symmetry sample using 2.885 × 10–2 and 10–3 mol L–1 bipy concentrations, respectively. Surface-enhanced Raman spectroscopy results of this work show that Mn nanostructures designed and engineered in this work can not only replace Ag and Au materials, but also provide a much higher enhancement factor.

scholarly journals Nanoparticle Properties and Synthesis Effects on Surface-Enhanced Raman Scattering Enhancement Factor: An Introduction

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Nathan D. Israelsen ◽  
Cynthia Hanson ◽  
Elizabeth Vargis
Keyword(s):  
Raman Spectroscopy ◽  
Enhancement Factor ◽  
Protective Coatings ◽  
Surface Enhanced Raman Spectroscopy ◽  
Raman Intensity ◽  
Specific Chemical ◽  
Sers Enhancement ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Enhanced Raman Scattering

Raman spectroscopy has enabled researchers to map the specific chemical makeup of surfaces, solutions, and even cells. However, the inherent insensitivity of the technique makes it difficult to use and statistically complicated. When Raman active molecules are near gold or silver nanoparticles, the Raman intensity is significantly amplified. This phenomenon is referred to as surface-enhanced Raman spectroscopy (SERS). The extent of SERS enhancement is due to a variety of factors such as nanoparticle size, shape, material, and configuration. The choice of Raman reporters and protective coatings will also influence SERS enhancement. This review provides an introduction to how these factors influence signal enhancement and how to optimize them during synthesis of SERS nanoparticles.

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