scholarly journals Surface Plasmons and Surface Enhanced Raman Spectra of Aggregated and Alloyed Gold-Silver Nanoparticles

2009 ◽  
Vol 2009 ◽  
pp. 1-5 ◽  
Author(s):  
Y. Fleger ◽  
M. Rosenbluh
Keyword(s):  
Silver Nanoparticles ◽  
Surface Enhanced Raman Spectroscopy ◽  
Laser Wavelength ◽  
Excitation Wavelength ◽  
Gold And Silver Nanoparticles ◽  
Sers Substrates ◽  
Raman Enhancement ◽  
Gold Silver ◽  
Surface Enhanced ◽  
Surface Enhanced Raman

Effects of size, morphology, and composition of gold and silver nanoparticles on surface plasmon resonance (SPR) and surface enhanced Raman spectroscopy (SERS) are studied with the purpose of optimizing SERS substrates. Various gold and silver films made by evaporation and subsequent annealing give different morphologies and compositions of nanoparticles and thus different position of the SPR peak. SERS measurements of 4-mercaptobenzoic acid obtained from these films reveal that the proximity of the SPR peak to the exciting laser wavelength is not the only factor leading to the highest Raman enhancement. Silver nanoparticles evaporated on top of larger gold nanoparticles show higher SERS than gold-silver alloyed nanoparticles, in spite of the fact that the SPR peak of alloyed nanoparticles is narrower and closer to the excitation wavelength. The highest Raman enhancement was obtained for substrates with a two-peak particle size distribution for excitation wavelengths close to the SPR.

Surface-Enhanced Raman Scattering Based on Au-DNA-Ag Plasmonic Nanoparticles

2020 ◽  
Vol 15 (11) ◽  
pp. 1307-1311
Author(s):  
Seyed Enayatollah Taghavi Moghaddam ◽  
Farzin Emami
Keyword(s):  
Silver Nanoparticles ◽  
Raman Scattering ◽  
Surface Enhanced Raman Scattering ◽  
Excitation Wavelength ◽  
Nano Particle ◽  
Gold And Silver Nanoparticles ◽  
Gold Silver ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Enhanced Raman Scattering

The dependence of the Surface-Enhanced Raman Scattering (SERS) by gold and silver nanoparticles on their shape is examined using the organic dye, as a probe molecule. SERS has been explored extensively for applications in sensing and imaging, but the design and optimization of efficient substrates are still challenging. In order to understand and optimize the SERS process in nanoparticles, gold and silver Nanospheres and their composition as gold-DNA-silver nanoparticle were synthesized and characterized according to their average size, zeta potential and UV/visible absorption. In fact, in this research, an asymmetric new plasmonic nano-particle is proposed and designed as gold-DNA-silver and is compared to gold, silver, gold-DNA-gold, and silver-DNA-silver nanoparticles. With the help of this new nanoparticle, we design and recommend a Raman booster so that the effect of Raman is improved noticeably. It will be shown that using the proposed asymmetric nano-particle of gold-DNA-silver, the absorbance, and intensity of Raman booster is improved noticeably. In suspensions of equal nano-particle and dye concentration, the SERS effect increases as gold- DNA-silver, clearly indicating that control over the number of local field hotspots can optimize the SERS efficiency. Notably, it is demonstrated that the SERS intensity per nanoparticle scales with the magnitude of the SPR absorbance at the excitation wavelength (785 nm), providing a clear guide to optimization of the process experimentally.

scholarly journals In-Situ Growth of Two-Dimensional Gold Nanoclusters on Glass Surface for On-Site Surface-Enhanced Raman Spectroscopic Detection

2021 ◽  
Vol 9 ◽  
Author(s):  
Bin Tang ◽  
Fangyuan Han ◽  
Liping Zhu ◽  
Zongchang Luo ◽  
Jialin Wang ◽  
...  
Keyword(s):  
Gold Nanoclusters ◽  
Electric Power Industry ◽  
Surface Enhanced Raman Spectroscopy ◽  
Infrared Range ◽  
Excitation Wavelength ◽  
Insulating Oil ◽  
Sers Substrates ◽  
Surface Enhanced ◽  
Surface Enhanced Raman

Analytical science has always been calling for simple, fast and ultra-sensitive methods to sense molecules of interest. Surface-Enhanced Raman Spectroscopy (SERS) has drawn much attention as a convenient tool for molecular fingerprint characterization. In addition to sample preparation, the key point of sensitive SERS detection is the preparation of highly reproducible and sensitive SERS substrates. In this paper, 2D gold nanoclusters are grown on surfaces of glass slips using an in-situ cyclic growth method in aqueous solutions to prepare high-quality SERS substrates, whose surface morphology can be effectively modulated by adjusting a few parameters during preparation. Substrates prepared with optimized parameters exhibit high SERS activity, uniform response, and good batch-to-batch reproducibility. Due to their strong absorption in the near-infrared range, the substrates can be combined with a portable Raman spectrometer with 785 nm excitation wavelength to detect traces of dibenzyl disulfide (DBDS), a major source of corrosive sulfur in mineral insulating oil. A detection limit lower than 1 mg/L can be achieved with the aid of a simple sample pretreatment method, representing a promising on-site insulating oil analysis method for electric power industry.

HIGH-ORDERED AND ULTRA-SENSITIVE PARTICLE-IN-BOWL METALLIC ARRAYS FOR SURFACE ENHANCED RAMAN SPECTROSCOPY

NANO ◽  
2014 ◽  
Vol 09 (04) ◽  
pp. 1450050 ◽  
Author(s):  
DI DI ◽  
PEITAO DONG ◽  
CHAOGUANG WANG ◽  
JIAN CHEN ◽  
JUNFENG WANG ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Fdtd Method ◽  
Disease Diagnosis ◽  
Surface Enhanced Raman Spectroscopy ◽  
Excitation Wavelength ◽  
Raman Enhancement ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Em Field ◽  
Lift Off

High-ordered particle-in-bowl (PIB) arrays are developed in this paper for surface enhanced Raman spectroscopy (SERS). A heterogeneous shadow mask, composing of the chrome (Cr) layer and colloid residues, is used to fabricate the silicon ( Si ) template from where the PIB arrays finally lift-off. The finite difference time domain (FDTD) method is employed to investigate the Raman enhancement mechanism of this PIB architecture. The electromagnetic (EM) field tends to concentrate in the gap between the bowl and the particle forming the "hot spots". The enhancement factor (EF) of the EM field is about 70 with an excitation wavelength of 785 nm. The Raman measurements validate the EM calculation of the PIB arrays. The EF is about 1.12 × 107 using Rodamine 6G (R6G) as probe molecule. The proposed PIB array is high-ordered in morphology and ultra-sensitive in Raman measurement, providing an ideal substrate for SERS-based bio-chemical sensing, disease diagnosis and analytical chemistry.

scholarly journals Electromagnetic Modelling of Raman Enhancement from Nanoscale Structures as a Means to Predict the Efficacy of SERS Substrates

2007 ◽  
Vol 2007 ◽  
pp. 1-10 ◽  
Author(s):  
Richard J. C. Brown ◽  
Jian Wang ◽  
Martin J. T. Milton
Keyword(s):  
Surface Enhanced Raman Spectroscopy ◽  
Sers Substrate ◽  
Structured Surfaces ◽  
Nanoscale Structures ◽  
Sers Substrates ◽  
Raman Enhancement ◽  
Electromagnetic Modelling ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
First Time

The requirement to optimise the balance between signal enhancement and reproducibility in surface enhanced Raman spectroscopy (SERS) is stimulating the development of novel substrates for enhancing Raman signals. This paper describes the application of finite element electromagnetic modelling to predict the Raman enhancement produced from a variety of SERS substrates with differently sized, spaced and shaped morphologies with nanometre dimensions. For the first time, a theoretical comparison between four major generic types of SERS substrate (including metal nanoparticles, structured surfaces, and sharp tips) has been performed and the results are presented and discussed. The results of the modelling are consistent with published experimental data from similar substrates.

Simple preparation of positively charged silver nanoparticles for detection of anions by surface-enhanced Raman spectroscopy

The Analyst ◽  
2015 ◽  
Vol 140 (9) ◽  
pp. 2988-2994 ◽  
Author(s):  
A. Stewart ◽  
S. Murray ◽  
S. E. J. Bell
Keyword(s):  
Raman Spectroscopy ◽  
Silver Nanoparticles ◽  
Zeta Potential ◽  
Surface Enhanced Raman Spectroscopy ◽  
Sers Substrates ◽  
Simple Preparation ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Positively Charged

Modification of Ag colloids with thiocholine bromide switches the zeta potential from ca. −50 mV to ca. +50 mV, giving SERS substrates which promote adsorption of anions.

scholarly journals Surface-enhanced Raman spectroscopy for the characterization of Vaccinium myrtillus L. bilberries of the Baltic–Nordic regions

2021 ◽  
Author(s):  
Lina Traksele ◽  
Valentinas Snitka
Keyword(s):  
Raman Spectroscopy ◽  
Silver Nanoparticles ◽  
Principal Component ◽  
Surface Enhanced Raman Spectroscopy ◽  
Vaccinium Myrtillus ◽  
Spectral Variation ◽  
Data Set ◽  
Sers Substrates ◽  
Surface Enhanced ◽  
Surface Enhanced Raman

AbstractIn this study, an investigation of the wild bilberries (Vaccinium myrtillus L.) of the different Baltic–Nordic regions using surface-enhanced Raman spectroscopy (SERS) combined with principal component analysis (PCA) is presented. The bilberries were collected in Lithuania, Latvia, Finland and Norway. The set of the SERS spectra of the berry extracts (pH ~ 4) were recorded on the silver nanoparticles based SERS substrates. The SERS spectra of the extracts were acquired using 532 nm laser as an excitation source. The morphology of the SERS substrates was evaluated by scanning electron microscopy (SEM) and the presence of the silver nanoparticles was confirmed by the energy-dispersive X-ray spectroscopy (EDX). The enhancement factor (EF) of the silver SERS substrates was found to be 105. It has been shown that a strong fluorescence background, associated with the phenolic compounds found in bilberries, can be subtracted due to the fluorescence-quenching properties of the silver nanoparticles. Therefore, an application of the SERS technique allowed to observe the characteristic peaks of the bilberries and the PCA tool enabled to evaluate the spectral variation across the entire SERS data set. The results presented in this paper show that the SERS technique coupled with PCA chemometric analysis might serve as a complementary method that allows to identify the country of origin of the bilberries based on the spectral differences.

The development of “fab-chips” as low-cost, sensitive surface-enhanced Raman spectroscopy (SERS) substrates for analytical applications

The Analyst ◽  
2015 ◽  
Vol 140 (3) ◽  
pp. 779-785 ◽  
Author(s):  
Ashley M. Robinson ◽  
Lili Zhao ◽  
Marwa Y. Shah Alam ◽  
Paridhi Bhandari ◽  
Scott G. Harroun ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Silver Nanoparticles ◽  
Chemical Sensing ◽  
Low Cost ◽  
Surface Enhanced Raman Spectroscopy ◽  
Sers Substrates ◽  
Sensing Applications ◽  
Wide Range ◽  
Surface Enhanced ◽  
Surface Enhanced Raman

Modification of metal-coated zari fabric chips with silver nanoparticles results in sensitive, affordable SERS substrates which are useful for a wide range of chemical sensing applications.

scholarly journals Cyclodextrin-assisted surface-enhanced Raman spectroscopy: a critical review

2021 ◽  
Author(s):  
Natalia E. Markina ◽  
Dana Cialla-May ◽  
Alexey V. Markin
Keyword(s):  
Raman Spectroscopy ◽  
Molecularly Imprinted Polymers ◽  
Surface Enhanced Raman Spectroscopy ◽  
Experimental Investigations ◽  
Real Potential ◽  
Sers Substrates ◽  
Raman Enhancement ◽  
Surface Enhanced ◽  
Physicochemical Studies ◽  
Surface Enhanced Raman

AbstractNumerous approaches have been proposed to overcome the intrinsically low selectivity of surface-enhanced Raman spectroscopy (SERS), and the modification of SERS substrates with diverse recognition molecules is one of such approaches. In contrast to the use of antibodies, aptamers, and molecularly imprinted polymers, application of cyclodextrins (CDs) is still developing with less than 100 papers since 1993. Therefore, the main goal of this review is the critical analysis of all available papers on the use of CDs in SERS analysis, including physicochemical studies of CD complexation and the effect of CD presence on the Raman enhancement. The results of the review reveal that there is controversial information about CD efficiency and further experimental investigations have to be done in order to estimate the real potential of CDs in SERS-based analysis. Graphical abstract

scholarly journals Economically reproducible surface-enhanced Raman spectroscopy of different compounds in thin film

2021 ◽  
Vol 45 (1) ◽  
pp. 1-11
Author(s):  
Ahatashamul Islam ◽  
Fariha Tasneem ◽  
Zulfiqar Hasan Khan ◽  
Asif Rakib ◽  
Syed Farid Uddin Farhad ◽  
...  
Keyword(s):  
Au Nanoparticles ◽  
Laser Excitation ◽  
Surface Enhanced Raman Spectroscopy ◽  
Raman Signal ◽  
Visible Absorption ◽  
Sers Substrates ◽  
Raman Enhancement ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Uv Visible

We report herein an economically cheap and functionally stable surfaceenhanced Raman scattering (SERS) protocol of two photoactive pigments Rhodamine 6G (R6G) and Kiton Red (KR), implemented in thin films of silver (Ag) and gold (Au) nanoparticles (AgNPs and AuNPs). Both commercially available and chemically synthesized nanoparticles were used. The suitability of the nanoparticles toward SERS activity was tested through UV-visible absorption spectroscopy and scanning electron microscopy (SEM). The AgNPs and AuNPs based SERS substrates in the form of films were fabricated onto square-sized aluminum(Al) plates by simple drop deposition of colloidal nanoparticles solution onto their polished surfaces. The prepared nanoparticle films were sufficiently dried and coated further with the probe (R6G and KR) molecules by employing the identical deposition technique. The enhanced Raman signals of R6G and KR in such composite film structures were then recorded through a custom-built dispersive Raman spectrometer with He-Ne laser excitation at 632.8 nm. Our AgNPsfilm-based SERS protocol could yield the magnitude of the Raman signal enhancement up to 104 times for both R6G and KR. Moreover, AuNPs-based film was found to be less efficient toward the Raman enhancement of both compounds. Our SERS substrates can be easily fabricated, and SERS spectra are reproducible and stable, allowing one to consistently get a reproducible result even after 6 months. J. Bangladesh Acad. Sci. 45(1); 1-11: June 2021

Surface enhanced Raman spectroscopy substrates with advanced spectral sensitivity prepared from five years old silver nanoplatelets

2016 ◽  
Vol 09 (06) ◽  
pp. 1642003 ◽  
Author(s):  
Anna A. Semenova ◽  
Eugene A. Goodilin
Keyword(s):  
Raman Spectroscopy ◽  
Silver Nanoparticles ◽  
Spectral Sensitivity ◽  
Surface Enhanced Raman Spectroscopy ◽  
Sers Substrates ◽  
Wide Range ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Flexible Applications ◽  
First Time

A new simple approach is suggested to prepare surface enhanced Raman spectroscopy (SERS) substrates with high effectiveness for various laser excitation wavelengths and analytes with different light absorption features by impregnation of porous cellulose materials by a mixture of silver nanoplatelets with a wide range of sizes and anisotropy. The suggested route provides a much better spectral sensitivity and flexible applications since SERS as a phenomenon is essential on the nanometer scale only. The mixing provides always a proper fraction of silver nanoparticles deposited onto the substrate thus guaranteeing the enhancement of Raman signals under given excitation conditions for a wider set of given analytes. The substrates were successfully prepared for the first time from silver nanoplatelets aged for five years. This confirms high chemical and morphological stability of stabilized silver nanoparticles and the ability to use them as precursors for application - ready materials.

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