Raman Signal Enhancement by Quasi-Fractal Geometries of Gold Nanoparticles

2018 ◽  
Author(s):  
Richard Darienzo ◽  
Tatsiana Mironava ◽  
Rina Tannenbaum
Keyword(s):  
Gold Nanoparticles ◽  
Surface Plasmon ◽  
Surface Enhanced Raman Spectroscopy ◽  
Synthesis Temperature ◽  
Localized Surface Plasmon ◽  
Raman Signal ◽  
Temperature Modulation ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Nanoparticle Morphology

<div><p>The synthesis of star-like gold nanoparticles (SGNs) in a temperature-controlled environment allows for temperature modulation and facilitates the growth of highly branched nanoparticles. By increasing the synthesis temperature, the level of branching increases as well. These highly branched features represent a distinctly novel, quasi-fractal nanoparticle morphology, referred to herein as gold nano caltrops (GNC). The increased surface roughness, local curvature and degree of inhomogeneity of GNC lend themselves to generating improved enhancement of the scattering signals in surface-enhanced Raman spectroscopy (SERS) via a mechanism in which the localized surface plasmon sites, or “hot spots,” provide the engine for the signal amplification, rather than the more conventional surface plasmon. Here, the synthesis procedure and the surface-enhancing capabilities of GNC are described and discussed in comparison with SGN.</p></div><div><br></div>

Raman Signal Enhancement by Quasi-Fractal Geometries of Gold Nanoparticles

2018 ◽  
Author(s):  
Richard Darienzo ◽  
Tatsiana Mironava ◽  
Rina Tannenbaum
Keyword(s):  
Gold Nanoparticles ◽  
Surface Plasmon ◽  
Surface Enhanced Raman Spectroscopy ◽  
Synthesis Temperature ◽  
Localized Surface Plasmon ◽  
Raman Signal ◽  
Temperature Modulation ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Nanoparticle Morphology

<div><p>The synthesis of star-like gold nanoparticles (SGNs) in a temperature-controlled environment allows for temperature modulation and facilitates the growth of highly branched nanoparticles. By increasing the synthesis temperature, the level of branching increases as well. These highly branched features represent a distinctly novel, quasi-fractal nanoparticle morphology, referred to herein as gold nano caltrops (GNC). The increased surface roughness, local curvature and degree of inhomogeneity of GNC lend themselves to generating improved enhancement of the scattering signals in surface-enhanced Raman spectroscopy (SERS) via a mechanism in which the localized surface plasmon sites, or “hot spots,” provide the engine for the signal amplification, rather than the more conventional surface plasmon. Here, the synthesis procedure and the surface-enhancing capabilities of GNC are described and discussed in comparison with SGN.</p></div><div><br></div>

scholarly journals Composite Structure Based on Gold-Nanoparticle Layer and HMM for Surface-Enhanced Raman Spectroscopy Analysis

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 587
Author(s):  
Zirui Wang ◽  
Yanyan Huo ◽  
Tingyin Ning ◽  
Runcheng Liu ◽  
Zhipeng Zha ◽  
...  
Keyword(s):  
Gold Nanoparticle ◽  
Surface Plasmon ◽  
Composite Structure ◽  
Surface Enhanced Raman Spectroscopy ◽  
Localized Surface Plasmon ◽  
Sers Substrate ◽  
Nanoparticle Layer ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Plasmon Polaritons

Hyperbolic metamaterials (HMMs), supporting surface plasmon polaritons (SPPs), and highly confined bulk plasmon polaritons (BPPs) possess promising potential for application as surface-enhanced Raman scattering (SERS) substrates. In the present study, a composite SERS substrate based on a multilayer HMM and gold-nanoparticle (Au-NP) layer was fabricated. A strong electromagnetic field was generated at the nanogaps of the Au NPs under the coupling between localized surface plasmon resonance (LSPR) and a BPP. Additionally, a simulation of the composite structure was assessed using COMSOL; the results complied with those achieved through experiments: the SERS performance was enhanced, while the enhancing rate was downregulated, with the extension of the HMM periods. Furthermore, this structure exhibited high detection performance. During the experiments, rhodamine 6G (R6G) and malachite green (MG) acted as the probe molecules, and the limits of detection of the SERS substrate reached 10−10 and 10−8 M for R6G and MG, respectively. Moreover, the composite structure demonstrated prominent reproducibility and stability. The mentioned promising results reveal that the composite structure could have extensive applications, such as in biosensors and food safety inspection.

scholarly journals In Situ Surface-Enhanced Raman Spectroscopy of Cellular Components: Theory and Experimental Results

Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1564 ◽  
Author(s):  
Mario D’Acunto
Keyword(s):  
Raman Spectroscopy ◽  
Protein Denaturation ◽  
Surface Enhanced Raman Spectroscopy ◽  
Small Sample ◽  
Experimental Results ◽  
Localized Surface Plasmon ◽  
Raman Signal ◽  
Label Free ◽  
Surface Enhanced ◽  
Surface Enhanced Raman

In the last decade, surface-enhanced Raman spectroscopy (SERS) met increasing interest in the detection of chemical and biological agents due to its rapid performance and ultra-sensitive features. Being SERS a combination of Raman spectroscopy and nanotechnology, it includes the advantages of Raman spectroscopy, providing rapid spectra collection, small sample sizes, characteristic spectral fingerprints for specific analytes. In addition, SERS overcomes low sensitivity or fluorescence interference that represents two major drawbacks of traditional Raman spectroscopy. Nanoscale roughened metal surfaces tremendously enhance the weak Raman signal due to electromagnetic field enhancement generated by localized surface plasmon resonances. In this paper, we detected label-free SERS signals for arbitrarily configurations of dimers, trimers, etc., composed of gold nanoshells (AuNSs) and applied to the mapping of osteosarcoma intracellular components. The experimental results combined to a theoretical model computation of SERS signal of specific AuNSs configurations, based on open cavity plasmonics, give the possibility to quantify SERS enhancement for overcoming spectral fluctuations. The results show that the Raman signal is locally enhanced inside the cell by AuNSs uptake and correspondent geometrical configuration generating dimers are able to enhance locally electromagnetic fields. The SERS signals inside such regions permit the unequivocal identification of cancer-specific biochemical components such as hydroxyapatite, phenylalanine, and protein denaturation due to disulfide bonds breaking between cysteine links or proline.

Si nanowire-gold nanoparticles heterostructures for surface enhanced Raman spectroscopy

2013 ◽  
Vol 1551 ◽  
pp. 67-72 ◽  
Author(s):  
Yuan Li ◽  
John C. Dykes ◽  
Nitin Chopra
Keyword(s):  
Gold Nanoparticles ◽  
Chemical Vapor ◽  
Surface Enhanced Raman Spectroscopy ◽  
Raman Signal ◽  
Si Nanowires ◽  
Particle Spacing ◽  
Si Nanowire ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Pressure Chemical

ABSTRACTHere, we present a method for the fabrication of silicon (Si) nanowires and Si nanowire-gold nanoparticles (AuNPs) heterostructures for surface-enhanced Raman scattering (SERS) effect. Branched Si nanowires were grown in atmospheric pressure chemical vapor deposition (CVD) process. Further decoration of these nanowires was achieved by a galvanic deposition of gold followed by annealing procedure. This resulted in Si nanowires-AuNPs heterostructures with controlled size and inter-particle spacing. Furthermore, the fabricated heterostructures were studied for Raman signal enhancement of the low concentration (∼10-6 M) dye (Rhodamine 6G, R6G). It was observed that heterostructuring of SiNWs with AuNPs led to improvement of R6G signals as compared to AuNPs dispersed on flat Si substrate.

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