Download or read book Interpreting High Resolution Tip Enhanced Raman Spectroscopy Images written by Pengchong Liu and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Raman spectroscopy is one of the fundamental techniques in chemical characterization. It measures the amount of photons and their frequency shifts scattered by the molecule under a given laser beam. The frequency shifts originate from the molecule's vibrations, which are determined by its microscopic structure. Thus, a Raman spectrum is often regarded as the molecule's "fingerprint". When the molecule is placed on a noble metal surface with some curvature, the Raman signals are greatly enhanced by the plasmonic near field at the surface. This technique is called "surface- enhanced Raman spectroscopy", or SERS. Because of the significantly improved sensitivity relative to regular Raman scattering, SERS has grown into a widely popular tool for chemical research and practical applications. Moreover, the molecule-metal interaction that lies in the center of the mechanism of SERS has been a hot topic of fundamental research since its discovery and has led to many variants in the development of spectroscopic techniques. Tip-enhanced Raman spectroscopy (TERS) integrates the scanning probe microscopy and SERS. Similar to SERS, the enhancement of Raman scattering in TERS benefits from the inhomogeneous near field induced by the plasmonic resonance of the noble metal nanostructure. However, the TERS spectrum of a molecule is often found different than SERS, and it changes with the tip position. The combination of the chemical sensitivity and the spatial resolution makes TERS a promising technique for microscopic characterization. A comprehensive demonstration of these unique features is TERS imaging. A TERS image is a two-dimensional map of the Raman intensity at a certain frequency varying with the scanning tip. It exhibits a sub-nanometer resolution and is specific to the corresponding vibrational mode. TERS imaging is considered as a visualization of molecular vibrations and sets stage for a new way of understanding molecules. Therefore, it is necessary to develop theoretical interpretation of TERS images and their connections to the underlying molecular vibration. However, interpreting TERS images is challenging as the brightspot pattern does not always strictly align with the vibrating atoms and the signals are very sensitive to experimental conditions. In this dissertation, three major aspects of TERS theory are explored: the effect of the plasmonic near field electromagnetic mechanism), the plasmonic resonance inside a subnanometer cavity (gap plasmonics), and the quantum mechanical interactions between the molecule and the substrate (the chemical mechanism). In particular, the critical conditions of the near field to achieve atomic resolution are found. It is also illustrated that the locally integrated Raman polarizability density is the sub-molecular property probed by the confined near field in TERS. It provides an intuitive description of the TERS imaging mechanism, which is usually hidden in the self-consistent cycles of conventional calculations using the time-dependent density functional theory. The distinct feature of TERS is largely ascribed to the unique plasmonic properties of a sub-nanometer junction consisting of a flat metal substrate and an atomically sharp tip. At this length scale, atomistic electrodynamics is adopted to describe the nanostructure because it captures the microscopic structure and at the same time retains the efficiency of a classical model.To study the charge-transfer plasmon due to quantum tunneling, a Hirshfeld partitioning scheme is developed to distinguish the plasmonic resonances within and across the coupled nanoparticles. Furthermore, this dissertation presents the development of a new theoretical method to better describe the substrate-molecule coupling, namely, exact frozen density embedding. The method to obtain the response properties of a molecule is derived based on the exact frozen density embedding within the framework of time-dependent density functional theory. Finally, a polarizable frozen density embedding method is developed to include the polarization effect due to the presence of a metal nanoparticle. The development of these theoretical tools is potentially applicable to the studies of the electronic structures of a TERS system.
Download or read book Raman Imaging written by Arnaud Zoubir and published by Springer. This book was released on 2012-07-27 with total page 388 pages. Available in PDF, EPUB and Kindle. Book excerpt: Raman imaging has long been used to probe the chemical nature of a sample, providing information on molecular orientation, symmetry and structure with sub-micron spatial resolution. Recent technical developments have pushed the limits of micro-Raman microscopy, enabling the acquisition of Raman spectra with unprecedented speed, and opening a pathway to fast chemical imaging for many applications from material science and semiconductors to pharmaceutical drug development and cell biology, and even art and forensic science. The promise of tip-enhanced raman spectroscopy (TERS) and near-field techniques is pushing the envelope even further by breaking the limit of diffraction and enabling nano-Raman microscopy.
Download or read book Tip Enhancement written by and published by Elsevier. This book was released on 2011-09-22 with total page 339 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book discusses the recent advances in the area of near-field Raman scattering, mainly focusing on tip-enhanced and surface-enhanced Raman scattering. Some of the key features covered here are the optical structuring and manipulations, single molecule sensitivity, analysis of single-walled carbon nanotubes, and analytic applications in chemistry, biology and material sciences. This book also discusses the plasmonic materials for better enhancement, and optical antennas. Further, near-field microscopy based on second harmonic generation is also discussed. Chapters have been written by some of the leading scientists in this field, who present some of their recent work in this field. ·Near-field Raman scattering·Tip-enhanced Raman spectroscopy·Surface-enhanced Raman spectroscopy·Nano-photonics·Nanoanalysis of Physical, chemical and biological materials beyond the diffraction limits·Single molecule detection
Download or read book Self assembled Monolayers of Thiols written by Abraham Ulman and published by . This book was released on 1998 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work looks at thin films and self-assembled monolayers of thiols. It is aimed at researchers in chemistry, materials science, electrical engineering, biology and condensed matter physics.
Download or read book Tip enhances Raman Spectroscopy Enabling Spectroscopy at the Nanoscale written by Nastaran Kazemi Zanjani and published by . This book was released on 2014 with total page 380 pages. Available in PDF, EPUB and Kindle. Book excerpt: The knowledge on the chemical and the structural properties of substances benefits strongly from characterization methods that can provide access to the sample's nanoscale building blocks. Not only should the sensitivity of these methods approach a high detection limit up to single molecule, but also the accessible spatial resolution must enable chemical imaging of individual nanoscale features of the substances. High resolution imaging is often provided by electron microscopes through methods such as transmission electron microscopy (TEM) and scanning electron microscopy (STM), nevertheless, these methods lack offering chemical information. Surface-enhanced spectroscopy was developed to improve the sensitivity of the chemical measurements through placing the sample onto rough metallic surfaces. However, in SERS, spatially resolved measurements are not possible since an ensemble of nanoscale features give birth to the SERS effect. The challenge of the simultaneous improvement of the spatial resolution and sensitivity was addressed indeed through combining high resolution optical microscopy with high sensitivity of surface-enhanced spectroscopy and was termed as tip-enhanced Raman spectroscopy. In this thesis, the confined electric field in proximity of the nanoscale apex of the metallic TERS tip is first investigated theoretically through conducting finite-difference time-domain calculations. The results were employed in optimization of the experimental TERS setup which is utilized in this thesis. The power of TERS in high resolution detection of nanoscale substances is then evaluated through TERS study of isolated single walled carbon nanotubes. The accessible high resolution is also used to acquire insight into the impact of structural strains on the molecular vibrations in silicon nanowires. The large surface sensitivity and specificity of TERS is also evaluated through TERS mapping of the adsorption sites of osteopontin phosphoprpteins on the surface of calcium oxalate microcrystal which are responsible for the formation of kidney stones in human body.
Download or read book Stimulated Raman Scattering Microscopy written by Ji-Xin Cheng and published by Elsevier. This book was released on 2021-12-04 with total page 612 pages. Available in PDF, EPUB and Kindle. Book excerpt: Stimulated Raman Scattering Microscopy: Techniques and Applications describes innovations in instrumentation, data science, chemical probe development, and various applications enabled by a state-of-the-art stimulated Raman scattering (SRS) microscope. Beginning by introducing the history of SRS, this book is composed of seven parts in depth including instrumentation strategies that have pushed the physical limits of SRS microscopy, vibrational probes (which increased the SRS imaging functionality), data science methods, and recent efforts in miniaturization. This rapidly growing field needs a comprehensive resource that brings together the current knowledge on the topic, and this book does just that. Researchers who need to know the requirements for all aspects of the instrumentation as well as the requirements of different imaging applications (such as different types of biological tissue) will benefit enormously from the examples of successful demonstrations of SRS imaging in the book. Led by Editor-in-Chief Ji-Xin Cheng, a pioneer in coherent Raman scattering microscopy, the editorial team has brought together various experts on each aspect of SRS imaging from around the world to provide an authoritative guide to this increasingly important imaging technique. This book is a comprehensive reference for researchers, faculty, postdoctoral researchers, and engineers. Includes every aspect from theoretic reviews of SRS spectroscopy to innovations in instrumentation and current applications of SRS microscopy Provides copious visual elements that illustrate key information, such as SRS images of various biological samples and instrument diagrams and schematics Edited by leading experts of SRS microscopy, with each chapter written by experts in their given topics
Download or read book Infrared and Raman Spectroscopic Imaging written by Reiner Salzer and published by John Wiley & Sons. This book was released on 2014-08-07 with total page 656 pages. Available in PDF, EPUB and Kindle. Book excerpt: This second edition of the successful ready reference is updated and revised with approximately 30% new content to reflect the numerous instrumental developments and improvements, as well as the significant expansion of this rapidly developing field. For example, the combination of IR imaging with AFM has enhanced the achievable lateral resolution by an order of magnitude down to a few hundred nanometers, thus launching a multiplicity of new applications in material science. Furthermore, Raman and IR spectroscopic imaging have become key technologies for the life sciences and today contribute tremendously to a better and more detailed understanding of numerous biological and medical research topics. The topical structure of this new edition is now subdivided into four parts. The first treats the fundamentals of the instrumentation for infrared and Raman imaging and mapping and an overview on the chemometric tools for image analysis. The second part describes a wide varie-ty of applications ranging from biomedical via food, agriculture and plants to polymers and pharmaceuticals. This is followed by a description of imaging techniques operating beyond the diffraction limit, while the final part covers special methodical developments and their utility in specific fields. With its many valuable practical tips, this is a must-have overview for researchers in academic and industrial laboratories wishing to obtain reliable results with this method.
Download or read book Tip Enhanced Raman Spectroscopy for Nanoelectronics written by Mischa Nicklaus and published by BoD – Books on Demand. This book was released on 2014-04-22 with total page 154 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation focuses on the application of Tip-Enhanced Raman spectroscopy (TERS) to non-transparent and non-conductive samples, allowing for the optical characterization of nanoelectronic devices. As such, nano-crystals are analyzed as a model system for the investigation of chemical and structural properties. Furthermore, a novel method for mapping the refractive index of materials with nanometer resolution is presented. The technological progress of electronics through miniaturization has reached the nanoscale while new materials with high performance and functional properties gain importance. Quality control and the scientific understanding of size effects in electronic nanostructures are required more than ever to consolidate existing technologies and to determine scaling limits of new materials. Conventional techniques, including scanning electron and scanning probe microscopy, provide topographic information but only very limited chemical information to analyze the physical properties of nanomaterials. Chemical and structural sensitivity is available by Raman or infrared spectroscopy, but with a spatial resolution limited to the microscale by the diffraction limit of light. TERS combines the virtues of scanning probe microscopy with those of optical spectroscopy to overcome the diffraction limit through the excitation of surface plasmons on a scanning probe tip to confine light to nanometers. In this work, a TERS system was installed to operate on opaque samples by employing optical side access. TERS probes were fabricated by electrochemical etching and operated in scanning tunneling microscopy and atomic force microscopy with quartz tuning forks to enable scanning on various surfaces. TERS was then applied to ferroelectric lead titanate nano-crystals on a platinized silicon substrate as a model system for nanostructured, charge-based memory devices at the onset of finite size effects.
Download or read book Surface Enhanced Vibrational Spectroscopy written by Ricardo Aroca and published by John Wiley & Sons. This book was released on 2006-05-01 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt: Surface Enhanced Vibrational Spectroscopy (SEVS) has reached maturity as an analytical technique, but until now there has been no single work that describes the theory and experiments of SEVS. This book combines the two important techniques of surface-enhanced Raman scattering (SERS) and surface-enhanced infrared (SEIR) into one text that serves as the definitive resource on SEVS. Discusses both the theory and the applications of SEVS and provides an up-to-date study of the state of the art Offers interpretations of SEVS spectra for practicing analysts Discusses interpretation of SEVS spectra, which can often be very different to the non-enhanced spectrum - aids the practicing analyst
Download or read book Tip enhanced Raman Spectroscopy in Ultra high Vacuum written by Philip Schambach and published by . This book was released on 2013 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Visualizing Chemistry written by National Research Council and published by National Academies Press. This book was released on 2006-06-01 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt: Scientists and engineers have long relied on the power of imaging techniques to help see objects invisible to the naked eye, and thus, to advance scientific knowledge. These experts are constantly pushing the limits of technology in pursuit of chemical imagingâ€"the ability to visualize molecular structures and chemical composition in time and space as actual events unfoldâ€"from the smallest dimension of a biological system to the widest expanse of a distant galaxy. Chemical imaging has a variety of applications for almost every facet of our daily lives, ranging from medical diagnosis and treatment to the study and design of material properties in new products. In addition to highlighting advances in chemical imaging that could have the greatest impact on critical problems in science and technology, Visualizing Chemistry reviews the current state of chemical imaging technology, identifies promising future developments and their applications, and suggests a research and educational agenda to enable breakthrough improvements.
Download or read book Modern Raman Spectroscopy written by Ewen Smith and published by John Wiley & Sons. This book was released on 2019-02-22 with total page 303 pages. Available in PDF, EPUB and Kindle. Book excerpt: Second edition of the guide to the modern techniques that demonstrate the potential of Raman spectroscopy Completely revised and updated, the second edition of Modern Raman Spectroscopy presents the information needed for clear understanding and application of the technique of Raman Spectroscopy in a range of areas such as pharmaceuticals, forensics, and biology. The authors—noted experts on the topic—reveal how to make full use of the critical information presented and include a wealth of examples of the pitfalls that can be encountered. The text opens with a description of the basic theory to assist readers in making a practical interpretation of Raman Spectra. Chapters include the main equations that are used in order to highlight the theory’s meaning and relevance while avoiding a full mathematical treatment. Modern Raman Spectroscopy provides a firm grounding, combined with a variety of references, from which to approach a more comprehensive study of specific aspects of Raman Spectroscopy. This new edition: Includes instrumentation sections that now contain Spatially Offset Raman scattering and transmission Raman scattering Offers an updated SERS chapter that presents recent examples and Tip enhanced Raman scattering Contains updated information with an emphasis on pharmaceutical, forensic, and biological applications Introduces modern techniques in the imaging and mapping of biological samples and more advanced methods which are becoming easier to use Written for users of Raman Spectroscopy in industry, including non-analysts, researchers, and academics, the second edition of Modern Raman Spectroscopy clearly demonstrates the potential of using Raman Spectroscopy for a wide range of applications.
Download or read book Surface Enhanced Raman Scattering written by Katrin Kneipp and published by Springer Science & Business Media. This book was released on 2006-06-21 with total page 473 pages. Available in PDF, EPUB and Kindle. Book excerpt: Almost 30 years after the first reports on surface-enhanced Raman signals, the phenomenon of surface-enhanced Raman scattering (SERS) is now well established. SERS gained particular interest after single-molecule Raman spectroscopy had been demonstrated. This book summarizes and discusses present theoretical approaches that explain the phenomenon of SERS and reports on new and exciting experiments and applications of the fascinating spectroscopic effect.
Download or read book Infrared and Raman Spectroscopy written by Peter Larkin and published by Elsevier. This book was released on 2017-11-13 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt: Infrared and Raman Spectroscopy, Principles and Spectral Interpretation, Second Edition provides a solid introduction to vibrational spectroscopy with an emphasis on developing critical interpretation skills. This book fully integrates the use of both IR and Raman spectroscopy as spectral interpretation tools, enabling the user to utilize the strength of both techniques while also recognizing their weaknesses. This second edition more than doubles the amount of interpreted IR and Raman spectra standards and spectral unknowns. The chapter on characteristic group frequencies is expanded to include increased discussions of sulphur and phosphorus organics, aromatic and heteroaromatics as well as inorganic compounds. New topics include a discussion of crystal lattice vibrations (low frequency/THz), confocal Raman microscopy, spatial resolution in IR and Raman microscopy, as well as criteria for selecting Raman excitation wavelengths. These additions accommodate the growing use of vibrational spectroscopy for process analytical monitoring, nanomaterial investigations, and structural and identity determinations to an increasing user base in both industry and academia. Integrates discussion of IR and Raman spectra Pairs generalized IR and Raman spectra of functional groups with tables and text Includes over 150 fully interpreted, high quality IR and Raman reference spectra Contains fifty-four unknown IR and Raman spectra, with a corresponding answer key
Download or read book Confocal Raman Microscopy written by Jan Toporski and published by Springer. This book was released on 2018-03-01 with total page 603 pages. Available in PDF, EPUB and Kindle. Book excerpt: This second edition provides a cutting-edge overview of physical, technical and scientific aspects related to the widely used analytical method of confocal Raman microscopy. The book includes expanded background information and adds insights into how confocal Raman microscopy, especially 3D Raman imaging, can be integrated with other methods to produce a variety of correlative microscopy combinations. The benefits are then demonstrated and supported by numerous examples from the fields of materials science, 2D materials, the life sciences, pharmaceutical research and development, as well as the geosciences.
Download or read book Near Field Optics written by D.W. Pohl and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 426 pages. Available in PDF, EPUB and Kindle. Book excerpt: Scanning near-field optical microscopy (SNOM, also known as NSOM) is a new local probe technique with a resolving power of 10--50 nm. Not being limited by diffraction, near-field optics (NFO) opens new perspectives for optical characterization and the understanding of optical phenomena, in particular in biology, microelectronics and materials science. SNOM, after first demonstrations in '83/'84, has undergone a rapid development in the past two to four years. The increased interest has been largely stimulated by the wealth of optical properties that can be investigated and the growing importance of characterization on the nanometer scale in general. Examples include the use of fluorescence, birefrigence and plasmon effects for applications in particular in biology, microelectronics and materials science, to name just a few. This volume emerged from the first international meeting devoted exclusively to NFO, and comprises a complete survey of the 1992 activities in the field, in particular the variety of instrumental techniques that are currently being explored, the demonstration of the imaging capabilities as well as theoretical interpretations - a highly nontrivial task. The comprehensive collection of papers devoted to these and related subjects make the book a valuable tool for anybody interested in near-field optics.
Download or read book Modern Raman Spectroscopy written by Ewen Smith and published by John Wiley & Sons. This book was released on 2013-03-15 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book reflects the dramatic increase in the number of Raman spectrometers being sold to and used by non-expert practitioners. It contains coverage of Resonance Raman and SERS, two hot areas of Raman, in a form suitable for the non-expert. Builds Raman theory up in stages without overloading the reader with complex theory Includes two chapters on instrumentation and interpretation that shows how Raman spectra can be obtained and interpreted Explains the potential of using Raman spectroscopy in a wide variety of applications Includes detailed, but concise information and worked examples
