Improvement in surface-enhanced Raman spectroscopy from cubic SiC semiconductor nanowhiskers by adjustment of energy levels

2016 ◽  
Vol 18 (39) ◽  
pp. 27572-27576 ◽  
Author(s):  
Wenna Liu ◽  
Tao Yang ◽  
Junhong Chen ◽  
Yingzhi Chen ◽  
Xinmei Hou ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Energy Levels ◽  
Surface Enhanced Raman Spectroscopy ◽  
Raman Signal ◽  
Sers Enhancement ◽  
Surface Enhanced ◽  
Surface Enhanced Raman

A highly enhanced, reproducible Raman signal of the 4-MBA molecule was observed on the surface of SiCNWs. Improved SERS enhancement was also achieved in these nanowhiskers by adjusting the energy levels.

scholarly journals Rapid uropathogen identification using surface enhanced Raman spectroscopy active filters

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Simon D. Dryden ◽  
Salzitsa Anastasova ◽  
Giovanni Satta ◽  
Alex J. Thompson ◽  
Daniel R. Leff ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Bacterial Infections ◽  
Surface Enhanced Raman Spectroscopy ◽  
Active Filters ◽  
Raman Signal ◽  
Rapid Diagnostics ◽  
Bacterial Classification ◽  
Surface Enhanced ◽  
Surface Enhanced Raman

AbstractUrinary tract infection is one of the most common bacterial infections leading to increased morbidity, mortality and societal costs. Current diagnostics exacerbate this problem due to an inability to provide timely pathogen identification. Surface enhanced Raman spectroscopy (SERS) has the potential to overcome these issues by providing immediate bacterial classification. To date, achieving accurate classification has required technically complicated processes to capture pathogens, which has precluded the integration of SERS into rapid diagnostics. This work demonstrates that gold-coated membrane filters capture and aggregate bacteria, separating them from urine, while also providing Raman signal enhancement. An optimal gold coating thickness of 50 nm was demonstrated, and the diagnostic performance of the SERS-active filters was assessed using phantom urine infection samples at clinically relevant concentrations (105 CFU/ml). Infected and uninfected (control) samples were identified with an accuracy of 91.1%. Amongst infected samples only, classification of three bacteria (Escherichia coli, Enterococcus faecalis, Klebsiella pneumoniae) was achieved at a rate of 91.6%.

scholarly journals Fabrication-friendly polarization-sensitive plasmonic grating for optimal surface-enhanced Raman spectroscopy

2020 ◽  
Vol 16 (1) ◽  
Author(s):  
Arpan Dutta ◽  
Tarmo Nuutinen ◽  
Khairul Alam ◽  
Antti Matikainen ◽  
Peng Li ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Fill Factor ◽  
Surface Enhanced Raman Spectroscopy ◽  
Transverse Magnetic ◽  
Raman Signal ◽  
Optical Resonance ◽  
Excitation Light ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Plasmonic Gratings

Abstract Plasmonic nanostructures are widely utilized in surface-enhanced Raman spectroscopy (SERS) from ultraviolet to near-infrared applications. Periodic nanoplasmonic systems such as plasmonic gratings are of great interest as SERS-active substrates due to their strong polarization dependence and ease of fabrication. In this work, we modelled a silver grating that manifests a subradiant plasmonic resonance as a dip in its reflectivity with significant near-field enhancement only for transverse-magnetic (TM) polarization of light. We investigated the role of its fill factor, commonly defined as a ratio between the width of the grating groove and the grating period, on the SERS enhancement. We designed multiple gratings having different fill factors using finite-difference time-domain (FDTD) simulations to incorporate different degrees of spectral detunings in their reflection dips from our Raman excitation (488 nm). Our numerical studies suggested that by tuning the spectral position of the optical resonance of the grating, via modifying their fill factor, we could optimize the achievable SERS enhancement. Moreover, by changing the polarization of the excitation light from transverse-magnetic to transverse-electric, we can disable the optical resonance of the gratings resulting in negligible SERS performance. To verify this, we fabricated and optically characterized the modelled gratings and ensured the presence of the desired detunings in their optical responses. Our Raman analysis on riboflavin confirmed that the higher overlap between the grating resonance and the intended Raman excitation yields stronger Raman enhancement only for TM polarized light. Our findings provide insight on the development of fabrication-friendly plasmonic gratings for optimal intensification of the Raman signal with an extra degree of control through the polarization of the excitation light. This feature enables studying Raman signal of exactly the same molecules with and without electromagnetic SERS enhancements, just by changing the polarization of the excitation, and thereby permits detailed studies on the selection rules and the chemical enhancements possibly involved in SERS.

scholarly journals New Trends in Raman Spectroscopy: From High-Resolution Geochemistry to Planetary Exploration

Elements ◽  
2020 ◽  
Vol 16 (2) ◽  
pp. 117-122 ◽  
Author(s):  
Olivier Beyssac
Keyword(s):  
Raman Spectroscopy ◽  
Surface Enhanced Raman Spectroscopy ◽  
Raman Signal ◽  
Time Resolved ◽  
The Earth ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Anti Stokes ◽  
Near Future ◽  
Very High

This article reviews nonconventional Raman spectroscopy techniques and discusses present and future applications of these techniques in the Earth and planetary sciences. Time-resolved spectroscopy opens new ways to limit or exploit luminescence effects, whereas techniques based on coherent anti-Stokes Raman scattering (CARS) or surface-enhanced Raman spectroscopy (SERS) allow the Raman signal to be considerably enhanced even down to very high spatial resolutions. In addition, compact portable Raman spectrometers are now routinely used out of the laboratory and are even integrated to two rovers going to Mars in the near future.

scholarly journals Designing dendronic-Raman markers for sensitive detection using surface-enhanced Raman spectroscopy

RSC Advances ◽  
2019 ◽  
Vol 9 (48) ◽  
pp. 28222-28227
Author(s):  
Priyanka Jain ◽  
Robi Sankar Patra ◽  
Sridhar Rajaram ◽  
Chandrabhas Narayana
Keyword(s):  
Raman Spectroscopy ◽  
Surface Enhanced Raman Spectroscopy ◽  
Sensitive Detection ◽  
Trace Detection ◽  
New Approach ◽  
Sers Enhancement ◽  
Surface Enhanced ◽  
Surface Enhanced Raman

A new approach of tuning SERS enhancement with the aid of coupling chemistry for trace detection. A greater number of Raman-active molecules are constrained in a dendronic framework as an improved SERS analyte.

Surface-Enhanced Raman Spectroscopy at a Silver Electrode as a Real-Time Detector in Flowing Streams

1992 ◽  
Vol 46 (1) ◽  
pp. 147-151 ◽  
Author(s):  
Neil J. Pothier ◽  
R. Ken Forcé
Keyword(s):  
Raman Spectroscopy ◽  
Real Time ◽  
Surface Enhanced Raman Spectroscopy ◽  
Silver Electrode ◽  
Raman Signal ◽  
Applied Potential ◽  
Charge Coupled Device ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Adsorption Desorption

An analytical application for Surface-Enhanced Raman Spectroscopy at a silver electrode is described. Real-time SER spectra of adenine and cytosine have been recorded in a 10-µL spectroelectrochemical flow cell under flowing conditions. Charge-coupled-device detection allowed high-quality spectra spanning a ∼1200 cm−1 region to be recorded with integration times of 4 seconds. A low-power He Ne laser was used as a source. SERS at the silver electrode offers rapid time response to adsorption/desorption by appropriate potential modulation. The technique is extremely reproducible and insensitive to temperature and flow rate. The effects of incident photon energy and applied potential on the intensity of the Raman signal are discussed.

Bacillus Spore Classification via Surface-Enhanced Raman Spectroscopy and Principal Component Analysis

2008 ◽  
Vol 62 (3) ◽  
pp. 267-272 ◽  
Author(s):  
J. Guicheteau ◽  
L. Argue ◽  
D. Emge ◽  
A. Hyre ◽  
M. Jacobson ◽  
...  
Keyword(s):  
Principal Component Analysis ◽  
Raman Spectroscopy ◽  
Bacterial Species ◽  
Principal Component ◽  
Component Analysis ◽  
Surface Enhanced Raman Spectroscopy ◽  
Raman Signal ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Bacillus Spores

Surface-enhanced Raman spectroscopy (SERS) can provide rapid fingerprinting of biomaterial in a nondestructive manner. The adsorption of colloidal silver to biological material suppresses native biofluorescence while providing electromagnetic surface enhancement of the normal Raman signal. This work validates the applicability of qualitative SER spectroscopy for analysis of bacterial species by utilizing principal component analysis (PCA) to show discrimination of biological threat simulants, based upon multivariate statistical confidence limits bounding known data clusters. Gram-positive Bacillus spores ( Bacillus atrophaeus, Bacillus anthracis, and Bacillus thuringiensis) are investigated along with the Gram-negative bacterium Pantoea agglomerans.

scholarly journals Highly Sensitive Surface Enhanced Raman Spectroscopy from Ag Nanoparticles Decorated Graphene Sheet

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Hui Song ◽  
Xin Li ◽  
Sweejiang Yoo ◽  
Yuan Wu ◽  
Weihua Liu ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Size Distribution ◽  
Ag Nanoparticles ◽  
Surface Enhanced Raman Spectroscopy ◽  
Sers Substrate ◽  
Ag Nps ◽  
Sers Enhancement ◽  
Surface Enhanced ◽  
Enhancement Factors ◽  
Surface Enhanced Raman

Surface enhanced Raman spectroscopy (SERS) is a powerful analytical technique and has been most intensively studied. In this work, electroless deposition is proposed for Ag nanoparticles (NPs) decorated on chemical vapor deposition (CVD) growth graphene sheets (GS) to create hybrid SERS substrate. From three aspects of size distribution, morphology, and coverage, Ag NPs controllable decoration on GS and SERS enhancement factors of the hybrid SERS substrate is investigated. 200–300 times enhanced SERS intensities are detected from the Ag NPs on GS hybrid as compared to pure GS. Controllable decoration is crucial for improving SERS enhancement factorsβEF, becauseβEFfrom quasi cubic Ag NPs on GS is 6.53 times stronger than that from spheric one; 1.6 timesβEFis detected while the Ag NPs size distribution is reduced to half, and when the coverage is doubled,βEFis nearly doubled. This controllable Ag NPs/GS hybrid is capable of serving as a high performance SERS substrate for efficient chemical and biological sensing applications.

scholarly journals A simple and reliable approach for the fabrication of nanoporous silver patterns for surface-enhanced Raman spectroscopy applications

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Angela Capaccio ◽  
Antonio Sasso ◽  
Giulia Rusciano
Keyword(s):  
Raman Spectroscopy ◽  
Inductively Coupled Plasma ◽  
Low Cost ◽  
Cost Effective ◽  
Surface Enhanced Raman Spectroscopy ◽  
Raman Signal ◽  
Plasmonic Nanostructures ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Good Signal

AbstractThe fabrication of plasmonic nanostructures with a reliable, low cost and easy approach has become a crucial and urgent challenge in many fields, including surface-enhanced Raman spectroscopy (SERS) based applications. In this frame, nanoporous metal films are quite attractive, due to their intrinsic large surface area and high density of metal nanogaps, acting as hot-spots for Raman signal enhancement. In this paper, we report a detailed study on the fabrication of nanoporous silver-based SERS substrates, obtained by the application of two successive treatments with an Inductively Coupled Plasma (ICP) system, using synthetic air and Ar as feeding gases. The obtained substrates exhibit a quite broad plasmonic response, covering the Vis–NIR range, and an enhancement factor reaching 6.5 $$\times\, 10^7$$ × 10 7 , estimated by using 4-mercaptobenzoic acid (4-MBA) as probe molecule at 532 nm. Moreover, the substrates exhibit a quite good spatial reproducibility on a centimeter scale, which assures a good signal stability for analytical measurements. Globally, the developed protocol is easy and cost effective, potentially usable also for mass production thanks to the remarkable inter-batches reproducibility. As such, it holds promise for its use in SERS-based sensing platforms for sensitive detection of targets molecules.

scholarly journals Role of multipolar plasmon resonances during surface-enhanced Raman spectroscopy on Au micro-patches

RSC Advances ◽  
2016 ◽  
Vol 6 (116) ◽  
pp. 115284-115289 ◽  
Author(s):  
Annette Dowd ◽  
Mathias Geisler ◽  
Shaoli Zhu ◽  
Michelle L. Wood ◽  
Michael B. Cortie
Keyword(s):  
Raman Spectroscopy ◽  
Surface Enhanced Raman Spectroscopy ◽  
Signal Enhancement ◽  
Raman Signal ◽  
Surface Enhanced ◽  
Plasmon Resonances ◽  
Surface Enhanced Raman

Large more reproducibly fabricated microstructures can also provide significant Raman signal enhancementviausually neglected multipolar plasmon resonances.

scholarly journals Liquid Surface-Enhanced Raman Spectroscopy (SERS) Sensor-Based Au-Ag Colloidal Nanoparticles for Easy and Rapid Detection of Deltamethrin Pesticide in Brewed Tea

Crystals ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 24
Author(s):  
Affi Nur Hidayah ◽  
Djoko Triyono ◽  
Yuliati Herbani ◽  
Rosari Saleh
Keyword(s):  
Raman Spectroscopy ◽  
Liquid Surface ◽  
Limit Of Detection ◽  
Surface Enhanced Raman Spectroscopy ◽  
Ease Of Use ◽  
Raman Signal ◽  
Colloidal Nanoparticles ◽  
Sers Substrate ◽  
Surface Enhanced ◽  
Surface Enhanced Raman

Deltamethrin pesticides can cause inflammation, nephrotoxicity and hepatotoxicity as well as affect the activity of antioxidant enzymes in tissues. As a result of this concern, there is a rising focus on the development of fast and reliable pesticide residue testing to minimise potential risks to humans. The goal of this study is to use Au-Ag colloid nanoparticles as liquid surface-enhanced Raman spectroscopy (SERS) to improve the Raman signal in the detection of deltamethrin pesticide in a brewed tea. The liquid SERS system is fascinating to study due to its ease of use and its unlikeliness to cause several phenomena, such as photo-bleaching, combustion, sublimation and even photo-catalysis, which can interfere with the Raman signal, as shown in the SERS substrate. Our liquid SERS system is simpler than previous liquid SERS systems that have been reported. We performed the detection of pesticide analyte directly on brewed tea, without diluting it with ethanol or centrifuging it. Femtosecond laser-induced photo-reduction was employed to synthesise the liquid SERS of Au, Au-Ag, and Ag colloidal nanoparticles. The SERS was utilised to detect deltamethrin pesticide in brewed tea. The result showed that liquid SERS-based Ag NPs significantly enhance the Raman signal of pesticides compared with liquid SERS-based Au NPs and Au-Ag Nanoalloys. The maximum residue limits (MRLs) in tea in Indonesia are set at 10 ppm. Therefore, this method was also utilised to detect and improve, to 0.01 ppm, the deltamethrin pesticide Limit of Detection (LOD).

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