Recent advances in linear and nonlinear Raman spectroscopy II

Following the first review on recent advances in linear and nonlinear Raman spectroscopy, the present review summarizes papers mainly published in the Journal of Raman Spectroscopy during 2007. This serves to give a fast overview of recent advances in this research field as well as to provide readers of this journal a quick introduction to the various subfields of Raman spectroscopy. It also reflects the current research interests of the Raman community. Similar reviews of highly active areas of Raman spectroscopy will appear in future issues of this journal. Copyright © 2008 John Wiley & Sons, Ltd.     

Recent advances in linear and nonlinear Raman spectroscopy. Part V

The purpose of the review is to provide a concise overview of recent advances in the broadly defined field of Raman spectroscopy as reflected in part by the many articles published each year in JRS as well as in trends across all related journals publishing in this research area. Context for this review is derived from statistical data on article counts obtained from Thomson Reuters ISI Web of Knowledge by year and by subfield of Raman spectroscopy. Additional information is gleaned from presentations featuring Raman spectroscopy presented at the meetings of the Federation of Analytical Chemistry and Spectroscopy Societies 2011 and the Sixth International Conference on Advanced Vibrational Spectroscopy 2011. Papers published in JRS in 2010, as reviewed here, reflect trends at the cutting edge of Raman spectroscopy, which is expanding rapidly as a sensitive photonic probe of matter at the molecular level with an ever‐widening sphere of novel applications. Copyright © 2011 John Wiley & Sons, Ltd.     

Recent advances in linear and nonlinear Raman spectroscopy. Part VII

The aim of this paper is to provide an overview of advances in the field of Raman spectroscopy as reflected in articles published each year in the Journal of Raman Spectroscopy as well as in trends across related journals publishing in this research area. The context for this review is derived from statistical data on article counts obtained from Thomson Reuters ISI Web of Knowledge by year and by subfield of Raman spectroscopy. Additional information is gleaned from presentations featuring Raman spectroscopy presented at the International Conference on Advanced Vibrational Spectroscopy in Kobe Japan in August 2013 and at SCIX 2013 sponsored by the Federation of Analytical Chemistry and Spectroscopy Societies in Milwaukee, Wisconsin, USA, October 2013. Papers published in the Journal of Raman Spectroscopy in 2012 are highlighted in this review and reflect topics and advances at the frontier of Raman spectroscopy, a field that is expanding rapidly as a sensitive photonic probe of matter at the molecular level in an ever widening sphere of novel applications. Copyright © 2013 John Wiley & Sons, Ltd.     

Recent advances in linear and nonlinear Raman spectroscopy. Part VI

The purpose of this review is to provide a concise overview of recent advances in the broadly defined field of Raman spectroscopy as reflected in part by the many articles published each year in Journal of Raman Spectroscopy as well as in trends across all related journals publishing in this research area. Context for this review is derived from statistical data on article counts obtained from Thomson Reuters ISI Web of Knowledge by year and by subfield of Raman spectroscopy. Additional information is gleaned from presentations featuring Raman spectroscopy presented at the XXIII International Conference on Raman Spectroscopy in Bangalore, India, in August 2012 and at Scientific Exchange 2012 sponsored by the Federation of Analytical Chemistry and Spectroscopy Societies in Kansas City, Missouri, USA, October 2012. Papers published in the Journal of Raman Spectroscopy in 2011 are highlighted in this review and reflect trends at the cutting edge of Raman spectroscopy, a field that is expanding rapidly as a sensitive photonic probe of matter at the molecular level with an ever widening sphere of novel applications. Copyright © 2012 John Wiley & Sons, Ltd.     

Recent advances in linear and nonlinear Raman spectroscopy. Part IV

The purpose of the review is to provide a concise overview of recent advances in the broadly defined field of Raman spectroscopy as reflected in part by the many articles published each year in the Journal of Raman Spectroscopy (JRS) as well as in trends across all related journals publishing in this research area. Context for the review is provided by considering statistical data on citations for the Thompson Reuters ISI Web of Science by year and by subfield of Raman spectroscopy. Additional statistics of number of papers and posters presented by category at the XXII International Conference on Raman Spectroscopy (ICORS 2010) is also provided. Papers published in JRS in 2009, as reviewed here, reflect trends at the cutting edge of Raman spectroscopy which is expanding rapidly as a sensitive photonic probe of matter at the molecular level with an ever widening sphere of novel applications. Copyright © 2010 John Wiley & Sons, Ltd.     

Recent advances in linear and non‐linear Raman spectroscopy. Part IX

This annual review is published to provide an overview of advances in the field of Raman spectroscopy as reflected in papers published each year in the Journal of Raman Spectroscopy (JRS) as well as in trends across related journals that have published papers in the broad field of Raman spectroscopy. The content is obtained from statistical data on article counts obtained from Thomson Reuters ISI Web of Science Core Collection by year and by subfield of Raman spectroscopy. Additional information is gleaned from presentations at the VIII International Conference on Advanced Vibrational Spectroscopy (ICAVS‐8) in Vienna, Austria in July 2015 and those featuring Raman scattering at SCIX 2015 organized by the Federation of Analytical Chemistry and Spectroscopy Societies (FACSS) in Providence, Rhode Island, USA, in September/October 2015. Coverage is also provided for topics from the conference ECONOS 2015 held in April in Leuven, Belgium. Finally, papers published in JRS in 2014 are highlighted and arranged by topics at the frontier of Raman spectroscopy. Taken from these various viewpoints, it is clear that Raman spectroscopy continues to be a rapidly expanding field that provides sensitive photonic information of matter at the molecular level in an ever‐widening arena of novel applications. Copyright © 2015 John Wiley & Sons, Ltd.     

Recent advances in linear and non‐linear Raman spectroscopy. Part III

Following the first two reviews on recent advances in linear and non‐linear Raman spectroscopy, the present review summarises papers mainly published in the Journal of Raman Spectroscopy during 2008. This again serves to give a brief overview of recent advances in this research field and to provide readers of this journal a quick introduction to the various sub‐fields of Raman spectroscopy. It also reflects the current research interests and trends in the Raman community. Copyright © 2009 John Wiley & Sons, Ltd.     

Applications of Raman spectroscopy in herbal medicine

Raman spectroscopic techniques are a group of chemical fingerprint detection methods based on molecular vibrational spectroscopy. They are compatible with aqueous solutions and are time saving, nondestructive, and highly informative. With complementary and alternative medicine (CAM) becoming increasingly popular, more people are consuming natural herbal medicines. Thus, chemical fingerprints of herbal medicines are investigated to determine the content of these products. In this study, I review the different types of Raman spectroscopic techniques used in fingerprinting herbal medicines, including dispersive Raman spectroscopy, resonance Raman spectroscopy, Fourier transform (FT)–Raman spectroscopy, surface-enhanced Raman scattering (SERS) spectroscopy, and confocal/microscopic Raman spectroscopy. Lab-grade Raman spectroscopy instruments help detect the chemical components of herbal medicines effectively and accurately without the need for complicated separation and extraction procedures. In addition, portable Raman spectroscopy instruments could be used to monitor the health and safety compliance of herbal products in the consumer market.     

Application of portable Raman spectroscopy and benchtop spatially offset Raman spectroscopy to interrogate concealed biomaterials

In this paper, we demonstrate the ability of portable Raman spectroscopy and benchtop spatially offset Raman spectroscopy (SORS) techniques to rapidly identify real and fake ivory samples. Both techniques were able to identify exposed genuine from fake ivory samples. In contrast to conventional Raman spectroscopy, SORS was, in addition, able to identify ivory concealed by plastics, paints, varnishes and cloth. Application of the SORS technique allows the interrogation of biomaterial samples through materials in which conventional Raman spectroscopic instrumentation cannot penetrate. Copyright © 2009 John Wiley & Sons, Ltd.     

In situ diagnostics of catalytic materials using tunable confocal Raman spectroscopy

A new Raman spectroscopic setup for in situ characterization of catalytic materials based on a tunable laser system and a confocal Raman microscope is described. The laser excitation wavelength is variable over a broad range from deep ultraviolet (UV) to near‐infrared allowing for targeted use of Raman diagnostics for catalyst characterization. By utilization of resonance effects, the sensitivity of the method can be strongly increased. The potential of the setup is illustrated by new in situ Raman results on dispersed vanadium oxide catalysts obtained at 217.5 and 280 nm UV laser excitation. Copyright © 2013 John Wiley & Sons, Ltd.     

双肽、多肽物质和蛋白质的紫外共振拉曼光谱研究现状

本文介绍了紫外共振拉曼光谱技术在双肽、多肽物质和蛋白质二级结构研究的现状和进展，双肽物质ＮＭＡ和ＧＬＹ—ＧＬＹ水溶液光异构化过程的紫外共振拉曼光谱研究，简述了紫外共振拉曼光谱实验技术要点。     

Fiber optic probes for linear and nonlinear Raman applications – Current trends and future development

This review focuses on fiber optic probes for linear and nonlinear Raman spectroscopy, especially for medical applications. It aims at providing an overview over contemporary technology, recent first clinical trials, and helps identifying future developments necessary to bring the emerging technology to clinical end users. After a short introduction to linear and nonlinear Raman spectroscopic modalities, general design considerations will be discussed and compared to common fiber probe setups. Subsequently, examples for medical applications of fiber optic Raman probes will be given concentrating on probes for linear Raman spectroscopy as these devices are technologically more mature compared to their counterparts based on nonlinear Raman spectroscopy. The review also includes a brief summary of first multimodal fiber optic probes and highlights their benefits for clinical applications. Finally, probes are introduced which employ either nonlinear Raman spectroscopy or surface enhanced spectroscopy.     

喇曼感生克尔效应光谱的琼斯矩阵分析

介绍喇曼感生克尔效应光谱(RIKES)的琼斯(Jones)矩阵分析方法.探测光束的传输强度不仅由所经过的每一个光学器件的琼斯矩阵所决定,而且还受到强的泵波在非线性介质样品中感生依赖于强度的二向色性和双折射(克尔效应)对琼斯矩阵的影响.同时计及样品和光学器件由强泵波作用下感生应力和其他外部产生的线双折射对喇曼感生克尔效应光谱观察的不利影响,导出测量系统的功率传输函数的完整表达式和喇曼感生克尔效应光谱的实现观察条件,最后简述以甲笨(C_7H_8)液体为试样的喇曼感生克尔效应光谱实验结果分析.     

Raman Spectroscopy for Protein Analysis

Abstract

Proteins are essential parts of organisms and participate in virtually every process within cells. Raman spectroscopy can be a powerful tool for the characterization of modified amino acids and proteins. In addition to the potential for quantitative results, it offers the advantage of not requiring any sample preparation. This review focuses on applications for protein analysis, published in the period 2010–2014.     

Passive signal enhancement in spatially offset Raman spectroscopy

We demonstrate experimentally, for the first time, the feasibility of enhancing signals in Spatially Offset Raman Spectroscopy (SORS) using a dielectric bandpass filter, building on our earlier experimental work on the enhancement of transmission Raman signals. The method is shown to lead to the enhancement of both the surface and subsurface Raman layer signal improving the signal‐to‐noise ratio of Raman spectra from the deep areas of samples, thus enhancing the technique's sensitivity and penetration depth. The filter is placed over the laser illumination zone, on the sample surface acting as a ‘unidirectional’ mirror transmitting the collimated laser beam on one side and reflecting photons escaping from the sample back into it. This enhances the degree of coupling of laser radiation into the medium and associated generated Raman signal. The feasibility study was performed on a two‐layer sample with the second layer located at the limit of the penetration depth of the method for this sample. The sample consisted of a 2.2‐mm over‐layer of a thinned paracetamol tablet followed by a 2‐mm layer of trans‐stilbene powder. The Raman signal was collected from a spatially offset region through a hole fabricated within the filter. The experiments demonstrate the presence of an enhancement of the Raman signal from both the layers by a factor of 4.4–4.5 and the improved signal‐to‐noise ratio of sublayer signal by a factor of 2.2, in agreement with photon shot noise dominated signal. Copyright © 2008 John Wiley & Sons, Ltd.     

Wide area Raman spectroscopy

Raman spectroscopy allows nondestructive analysis of materials using laser illumination. However, most Raman spectrometers can only provide good signal levels and sufficient spectral resolution, by focusing the laser to micrometer-sized spots. This equates to enormous laser intensities, which for samples with even very minor optical absorption either means destroying or damaging it by absorbing even a tiny fraction of the laser power, or it means reducing the laser intensity and hence the signal level. Furthermore, Raman signals generated above or below the focal plane are rejected in traditional Raman spectrometers. As signal levels are already extremely low in Raman spectroscopy, several schemes offer an alternative to focusing down to a diffraction-limited spot, to increase the area by up to 6 orders of magnitude, and increase the sampling depth. This review describes and compares these schemes, and estimates the typical illumination areas.     

Raman and surface-enhanced Raman spectroscopy evidence for oxidation-induced decomposition of graphite

It has been proposed that reduction of exfoliated graphite oxide could be a potential method for producing large quantities of graphene. Raman and surface-enhanced Raman spectroscopy are used to show that oxidation of graphite and exfoliated graphite significantly increases the defect structure of both materials. This would likely lead to a heavily defected graphene structure when oxygen is removed. To insure the observed decomposition is not due to the laser light, the effect of laser intensity on the materials was investigated. It was found that at the highest laser intensity (1.4 × 10⁸ W/M²) there was a significant increase in defects. However, lower laser intensity was found which did not produce defects and was used in the studies of the effect of oxidation on the spectra.     

Microbiological identification by surface-enhanced Raman spectroscopy

New methods for pathogens identification are of growing interest in clinical and food sectors. The challenge remains to develop rapid methods that are more simple, reliable, and specific. Surface-enhanced Raman spectroscopy (SERS) appears to be a promising tool to compete with current untargeted identification methods. This article presents the intensive research devoted to the use of SERS for bacterial identification, from the first to the very recent published results. Compared to normal Raman spectroscopy, the introduction of nanoparticles for SERS acquisition introduces a new degree of complexity. Bacterial Raman fingerprints, which are already subject to high spectral variability for a given strain, become then very dependent on numerous experimental parameters. To overcome these limitations, several approaches have been proposed to prepare the sample, from the microbiological culture conditions to the analysis of the spectrum including the coupling of nanoparticles on the bacterial membrane. Main strategies proposed over the last 20 years are examined here and discussed in the perspective of a protocol transfer towards industry.     

Subtracted shifted Raman spectroscopy of organic dyes and lakes

Resonance Raman spectroscopy has been utilized to identify vegetal and animal dyes and lakes. These compounds have been used by artists since antiquity, and their identification has important implications in art history and conservation. The resonance condition is useful when working with real ancient objects so as to enhance the Raman scattering of chromophores with respect to the strong signal of the matrix, such as the textile or parchment over which the colorant is supported. The strong fluorescence that generally characterizes the resonance Raman spectra was eliminated by using subtracted shifted Raman spectroscopy (SSRS). A systematic study on reference organic dyes was primarily carried out to evaluate the suitability of the method and to estimate the strengths and limitations of the spectrum reconstruction process. The method was then applied to the noninvasive identification of madder on ancient dyed silk textiles such as an altar table cloth and a manutergium attributed to the Egyptian artistic textile production of the 10th–11th Century A.D. Copyright © 2009 John Wiley & Sons, Ltd.     

凝聚态物质中的光声喇曼效应理论

用热弹性理论系统地分析了凝聚态物质的光声喇曼效应,分别导出了连续和脉冲激光泵浦下的光声喇曼信号表达式,并做了数值估算.