scholarly journals Oxygen Vacancy Dynamics in Highly Crystalline Zinc Oxide Film Investigated by PIERS Effect

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4423
Author(s):  
Grégory Barbillon
Keyword(s):  
Raman Spectroscopy ◽  
Metallic Nanoparticles ◽  
Oxygen Vacancies ◽  
Uv Light ◽  
Surface Enhanced Raman Spectroscopy ◽  
Oxide Semiconductor ◽  
Semiconductor Film ◽  
Raman Signal ◽  
Zinc Oxide Film ◽  
Zno Film

Surface-enhanced Raman spectroscopy (SERS) is commonly employed as an analysis or detection tool of biological and chemical molecules. Recently, an alternative section of the SERS field has appeared, called photo-induced enhanced Raman spectroscopy (PIERS). This PIERS effect is based on the production of the oxygen vacancies (V0) in metal-oxide semiconductor thin-film (or other structures) by irradiation with UV light, thus enabling a Raman signal enhancement of chemical molecules through charge transfer processes between this photo-irradiated semiconductor film (or other structures) and these chemical molecules via metallic nanoparticles deposited on this photo-irradiated substrate. The PIERS technique can enable studying the dynamics of the oxygen vacancies under ambient and operando conditions compared to conventional tools of analysis. In this paper, we present the results obtained on the formation and healing rates of surface oxygen vacancies (V0) in a highly crystalline ZnO film investigated by the PIERS effect, and we compare these results to the literature in order to study the effect of the crystallinity on these formation and healing rates of V0 in a ZnO film.

scholarly journals Single mode waveguide platform for spontaneous and surface-enhanced on-chip Raman spectroscopy

2016 ◽  
Vol 6 (4) ◽  
pp. 20160015 ◽  
Author(s):  
Ashim Dhakal ◽  
Frédéric Peyskens ◽  
Stéphane Clemmen ◽  
Ali Raza ◽  
Pieter Wuytens ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Collection Efficiency ◽  
Single Mode ◽  
Surface Enhanced Raman Spectroscopy ◽  
Oxide Semiconductor ◽  
Design Parameters ◽  
Raman Signal ◽  
Theoretical Concepts ◽  
Surface Enhanced ◽  
On Chip

We review an on-chip approach for spontaneous Raman spectroscopy and surface-enhanced Raman spectroscopy based on evanescent excitation of the analyte as well as evanescent collection of the Raman signal using complementary metal oxide semiconductor (CMOS)-compatible single mode waveguides. The signal is either directly collected from the analyte molecules or via plasmonic nanoantennas integrated on top of the waveguides. Flexibility in the design of the geometry of the waveguide, and/or the geometry of the antennas, enables optimization of the collection efficiency. Furthermore, the sensor can be integrated with additional functionality (sources, detectors, spectrometers) on the same chip. In this paper, the basic theoretical concepts are introduced to identify the key design parameters, and some proof-of-concept experimental results are reviewed.

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 Laser Raman Spectroscopy with Different Excitation Sources and Extension to Surface Enhanced Raman Spectroscopy

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Md. Wahadoszamen ◽  
Arifur Rahaman ◽  
Nabil Md. Rakinul Hoque ◽  
Aminul I Talukder ◽  
Kazi Monowar Abedin ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Silver Nanoparticles ◽  
Rhodamine 6G ◽  
Detection Efficiency ◽  
Colloidal Suspension ◽  
Surface Enhanced Raman Spectroscopy ◽  
Laser Raman Spectroscopy ◽  
Raman Signal ◽  
Fluorescence Signal ◽  
Present System

A dispersive Raman spectrometer was used with three different excitation sources (Argon-ion, He-Ne, and Diode lasers operating at 514.5 nm, 633 nm, and 782 nm, resp.). The system was employed to a variety of Raman active compounds. Many of the compounds exhibit very strong fluorescence while being excited with a laser emitting at UV-VIS region, hereby imposing severe limitation to the detection efficiency of the particular Raman system. The Raman system with variable excitation laser sources provided us with a desired flexibility toward the suppression of unwanted fluorescence signal. With this Raman system, we could detect and specify the different vibrational modes of various hazardous organic compounds and some typical dyes (both fluorescent and nonfluorescent). We then compared those results with the ones reported in literature and found the deviation within the range of ±2 cm−1, which indicates reasonable accuracy and usability of the Raman system. Then, the surface enhancement technique of Raman spectrum was employed to the present system. To this end, we used chemically prepared colloidal suspension of silver nanoparticles as substrate and Rhodamine 6G as probe. We could observe significant enhancement of Raman signal from Rhodamine 6G using the colloidal solution of silver nanoparticles the average magnitude of which is estimated to be 103.

Raman Spectroscopy for the Study of XVI-XVII Centuries Colonial Paintings

2014 ◽  
Vol 1618 ◽  
pp. 141-151 ◽  
Author(s):  
Ma. A. García-Bucio ◽  
E. Casanova-González ◽  
J. L. Ruvalcaba-Sil
Keyword(s):  
Raman Spectroscopy ◽  
San Francisco ◽  
Reference Materials ◽  
Analytical Techniques ◽  
Surface Enhanced Raman Spectroscopy ◽  
Raman Signal ◽  
Invasive Approach ◽  
Full Characterization ◽  
Surface Enhanced Raman ◽  
Historical Objects

ABSTRACTOutstanding information about the material composition and pictorial techniques of the New Spain Colonial painting can be obtained via a full characterization using a set of analytical techniques. Given the cultural importance of this painting, a non-invasive approach is preferred. Moreover, the preparation and use of reference materials using original recipes is necessary for a correct interpretation of the spectroscopic data from historical objects. Here, we present the results obtained via an in-situ Raman spectroscopic analysis of a set of pictorial reference materials, created according to XVI and XVII centuries’ recipes. Several difficulties were encountered, such as the low Raman detection signal, an intrinsic fluorescence of the material, and in some cases even laser-induced degradation. For this reason, the usual molecular Raman analysis was extended to Surface Enhanced Raman Spectroscopy (SERS), which enhances the Raman signal and quenches the fluorescence. It was then applied to the analysis of two wood paintings from the ex-convent San Francisco Tepeyanco, in Tlaxcala.

scholarly journals Current and Future Advancements of Raman Spectroscopy Techniques in Cancer Nanomedicine

2021 ◽  
Vol 22 (23) ◽  
pp. 13141
Author(s):  
Elisabetta Canetta
Keyword(s):  
Raman Spectroscopy ◽  
Imaging Techniques ◽  
Rapid Development ◽  
Surface Enhanced Raman Spectroscopy ◽  
Cancer Diagnostics ◽  
Raman Signal ◽  
Therapeutic Effects ◽  
Cancer Nanomedicine

Raman scattering is one of the most used spectroscopy and imaging techniques in cancer nanomedicine due to its high spatial resolution, high chemical specificity, and multiplexity modalities. The flexibility of Raman techniques has led, in the past few years, to the rapid development of Raman spectroscopy and imaging for nanodiagnostics, nanotherapy, and nanotheranostics. This review focuses on the applications of spontaneous Raman spectroscopy and bioimaging to cancer nanotheranostics and their coupling to a variety of diagnostic/therapy methods to create nanoparticle-free theranostic systems for cancer diagnostics and therapy. Recent implementations of confocal Raman spectroscopy that led to the development of platforms for monitoring the therapeutic effects of anticancer drugs in vitro and in vivo are also reviewed. Another Raman technique that is largely employed in cancer nanomedicine, due to its ability to enhance the Raman signal, is surface-enhanced Raman spectroscopy (SERS). This review also explores the applications of the different types of SERS, such as SERRS and SORS, to cancer diagnosis through SERS nanoprobes and the detection of small-size biomarkers, such as exosomes. SERS cancer immunotherapy and immuno-SERS (iSERS) microscopy are reviewed.

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.

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 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.

Sign in / Sign up

Export Citation Format

Share Document