Download or read book Theoretical Studies of Surface enhanced Raman Spectra of Pyridine Adsorbed on Silver Cluster and 4 4 bipyridine Molecular Junction Based on Ab Initio Molecular Dynamics Simulations written by and published by . This book was released on 2013 with total page 202 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Surface Enhanced Raman Studies of the Electroactive Forms of Substituted Pyridines written by Mark Randall Anderson and published by . This book was released on 1987 with total page 626 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Recent Developments In Plasmon supported Raman Spectroscopy 45 Years Of Enhanced Raman Signals written by Katrin Kneipp and published by World Scientific. This book was released on 2017-12-12 with total page 513 pages. Available in PDF, EPUB and Kindle. Book excerpt: Surface enhanced Raman scattering (SERS) might be one of the most impressive effects to demonstrate the power of plasmonic approaches in spectroscopy and became one of the 'triggers' for the rapidly emerging field of plasmonics.This book provides a review of some recent developments in SERS, such as tip enhanced Raman scattering (TERS), reports new experimental observations, sophisticated new SERS-active structures and substrates, new theoretical insight to explain the effect as well as exciting applications in various fields such as analytical science, biomedicine and nanotechnology.Written for graduate students and established researchers looking for inspiration for future work, its interdisciplinary nature makes the book suitable for readers in the fields of chemistry, physics, biology, medicine, nanotechnology and materials science.

Download or read book Surface Enhanced Raman Scattering New Theoretical Approaches Materials and Strategies written by Ivano Alessandri and published by Frontiers Media SA. This book was released on 2020-03-25 with total page 175 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Surface Enhanced Raman Spectroscopy of Pentaammineosmium III II and Pentaammineruthernium II Containing Pyridine Pyrazine Or 4 4 Bipyridine Ligands at Silver Electrodes Vibrational Assignments written by S. Farquharson and published by . This book was released on 1984 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: Detailed vibrational assignments are described for Surface Enhanced Raman (SER) spectra of pentaamminoeosmium(III), (II) and pentaammineruthenium(II) containing pyridine (py), pyrazine (pz), and 4,4'-bipyridine (bpy) ligands adsorbed at the silver-aqueous interface. The assignments are based on group symmetry analysis, deuteration effects, and by comparison with corresponding normal Raman and infrared spectra for the solid-phase complexes and surface and bulk Raman spectra for the corresponding free ligands. Most bands present in the normal Raman and/or infrared spectra also appear in the SER spectra. This results from the high intensity of the SER spectra along with the relaxation of vibrational selection rules for adsorbed molecules. The appearance of intense SER spectra for Os(NH3)5py(III)/(II) and RuII(NH3)5py is noteworthy since unlike free pyridine, these lack an available nitrogen for surface coordination. The results illustrate the virtues of electrochemical SER spectroscopy for examining the detailed vibrational properties of coordination compounds, including those in oxidation states (such as Os(II) here) that are difficult to obtain pure in bulk media. (Author).

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 Surface Enhanced Raman Spectroscopy for Biophysical Applications written by Claudia Fasolato and published by Springer. This book was released on 2018-12-05 with total page 167 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book explores the phenomenon of surface-enhanced Raman scattering (SERS), the huge amplification of Raman signal from molecules in the proximity of a metallic nanostructured surface, allowing readers to gain an in-depth understanding of the mechanisms affecting the spectroscopic response of SERS-active systems for effective applications. SERS spectroscopy is an ultrasensitive analytical technique with great potential for applications in the field of biophysics and nanomedicine. As examples, the author presents the design of nanocolloid-based SERS-active substrates for molecular sensing and of a folate-based SERS-active nanosensor capable of selectively interacting with cancer cells, enabling cancer diagnostics and therapy at the single-cell level. The author also suggests novel paths for the systematization of the SERS nanosystem design and experimental protocols to maximize sensitivity and reproducibility, which is essential when real-world biomedical applications are the goal of the study. With a combined approach, both fundamental and applied, and a detailed analysis of the state of the art, this book provides a valuable overview both for students new to SERS spectroscopy and for experts in the field.

Download or read book Ultrahigh vacuum Studies of Surface Enhanced Raman Scattering from Absorbates on Modulated Silver Surfaces written by Pia Naoko Sanda and published by . This book was released on 1982 with total page 300 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Surface enhanced Raman Scattering from a Modified Silver Electrode written by and published by . This book was released on 2002 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Electrochemical and spectroelectrochemical data was obtained for a silver electrode modified with oxazine 720. A quasi-reversible redox behaviour was observed for the modified electrode. Surface adsorption density, calculated from the measured electrochemical charge transfer, is higher than would be expected for a monolayer of flat-adsorbed oxazine 720. Surface-enhanced Raman scattering (SERS) data, in conjunction with results of a density functional theory (DFT) calculation, suggest that the molecule is adsorbed with its rings perpendicular to the electrode surface, consistent with the electrochemically estimated adsorption density. SERS was recorded in situ at different applied potentials. The SERS intensity remains relatively stable between -200 and -500 mV (versus AglAgCl Cl-sat), but decreases dramatically as the applied potential is made more negative than -500 mV. Ths is consistent with the onset of oxazine 720 reduction observed during cyclic voltammetry. The spectroelectrochemical data indicates that oxazine 720 remains adsorbed at the SERS-active sites even in its reduced form. Similar in situ SERS data was collected for rhodamine 6G and pyridine. Spectra in the Stokes and anti-Stokes regions were obtained at several applied potentials using two different laser excitation energies. Normalized ratios of the anti-Stokes to Stokes intensities were calculated for various vibrational bands of the three molecules. The measured ratios vary with changes in the excitation energy, the applied voltage and the energy of the vibrational mode being investigated. The ratios for oxazine 720 show a preferential enhancement of the Stokes scattering while the ratios for rhodamine 6G indicate an enhancement of the anti-Stokes scattering. For pyridine, the preferential enhancement changes between Stokes and anti-Stokes depending on the excitation wavelength used, the applied voltage and the vibrational band being examined. The main trends of the anti-Stokes to Stokes ratios ca.

Download or read book Principles of Surface Enhanced Raman Spectroscopy written by Eric Le Ru and published by Elsevier. This book was released on 2008-11-17 with total page 688 pages. Available in PDF, EPUB and Kindle. Book excerpt: SERS was discovered in the 1970s and has since grown enormously in breadth, depth, and understanding. One of the major characteristics of SERS is its interdisciplinary nature: it lies at the boundary between physics, chemistry, colloid science, plasmonics, nanotechnology, and biology. By their very nature, it is impossible to find a textbook that will summarize the principles needed for SERS of these rather dissimilar and disconnected topics. Although a basic understanding of these topics is necessary for research projects in SERS with all its many aspects and applications, they are seldom touched upon as a coherent unit during most undergraduate studies in physics or chemistry. This book intends to fill this existing gap in the literature. It provides an overview of the underlying principles of SERS, from the fundamental understanding of the effect to its potential applications. It is aimed primarily at newcomers to the field, graduate students, researchers or scientists, attracted by the many applications of SERS and plasmonics or its basic science. The emphasis is on concepts and background material for SERS, such as Raman spectroscopy, the physics of plasmons, or colloid science, all of them introduced within the context of SERS, and from where the more specialized literature can be followed. Represents one of very few books fully dedicated to the topic of surface-enhanced Raman spectroscopy (SERS) Gives a comprehensive summary of the underlying physical concepts around SERS Provides a detailed analysis of plasmons and plasmonics

Download or read book Surface enhanced Raman Scattering from a Modified Silver Electrode written by Aaron Craig Sanderson and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book SURFACE ENHANCED RAMAN SCATTERING STUDIES OF 2 AND 4 VINYLPYRIDINES ADSORBED ON SILVER COLLOIDS written by NOEMI GRACIELA MIRKIN and published by . This book was released on 1989 with total page 340 pages. Available in PDF, EPUB and Kindle. Book excerpt: developed and refined for the vinylpyridines. The calculated frequencies are in excellent agreement with the experimental results.

Download or read book Selected Papers on Surface enhanced Raman Scattering written by Milton Kerker and published by . This book was released on 1990 with total page 728 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Dipole quadrupole Theory of Surface Enhanced Raman Scattering written by A. M. Polubotko and published by . This book was released on 2009 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is devoted to explanation of SERS in terms of the strong dipole and especially quadruple light-molecule interactions arising in surface fields strongly varying in space in the region of strongly irregular surface roughness. The influence of the quadruple interaction is a matter of principle, since it provides explanation for the appearance of forbidden bands arising in a great number of experiments on SERS on symmetrical molecules. This essential detail in fact is absent in all other SERS theories, that does not permit to create a closed theory, which explains the majority of experimental facts accompanying SERS by a unitary approach. Moreover as it is demonstrated in the book the huge enhancement in the phenomenon of Single Molecule Detection by the SERS method can be explained exclusively by the strong quadruple light-molecule interaction. The first part of the book is devoted to a brief description of main SERS characteristics and critical analysis of theoretical approaches. Further the theory of electromagnetic field near some model kinds of rough surfaces and some other systems and the theory of the SER cross-section for arbitrary and symmetrical molecules are presented in detail. The obtained expressions helps to establish selection rules for contributions in the SER cross-section and analyse the SER spectra of symmetrical molecules. This analysis corroborates main specific features of the SER spectra of symmetrical molecules and some anomalies, which exist in these spectra for some specific conditions. The existence of electrodynamic forbiddance of the quadruple scattering mechanism for the methane molecule and molecules with cubic symmetry groups is established. The above theory permits to explain not only the huge enhancement in the phenomenon of Single -Molecule Detection but the blinking of the SERS signal too. The first layer effect, arising in the first layer of absorbed molecules also is considered in detail. It appears that the nature of this phenomenon is the electrodynamic enhancement, which is very large just in the first layer. The other phenomena, accompanying SERS are accounted for. It is demonstrated that the theory is in a good agreement with the SERS experiments and explains quite a number of characteristics related to the SERS phenomenon.

Download or read book Understanding Surface enhanced Raman Scattering Using a Raman Bond Model written by Ran Chen and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Surface-enhanced Raman scattering (SERS) is widely applied because of its high sensitivity and chemical specificity. SERS enhancements arise from two complementary mechanisms: the electromagnetic mechanism (EM) and the chemical mechanism (CM). EM helps to explain the high sensitivity, and the chemical specificity is mainly explained by CM. In EM, SERS enhancements are explained by local field enhancements due to surface plasmons and SERS enhancements approximately scale with field enhancements to the fourth power. In CM, SERS enhancements are attributed to bonding interactions between molecules and metal, and electronic structure simulations are usually applied to evaluate chemical enhancements. CM models have been developed to interpret chemical enhancements based on electronic structure simulations, and a transition based interpretation is shared by most of the models. In the transition based interpretation, chemical enhancements are explained by molecular transitions with decreased energy gaps and new emerged charge transfer transitions. Such transition based interpretation works well when specific transitions can be identified as the main contributions to the enhancements. However, when a large number of transitions contribute, a quantitative explanation requires an analysis of many transitions while a simple explanation is made by focusing on few transitions. To build a simple and quantitative interpretation of chemical enhancements, we develop a Raman bond model. The Raman bond model adopts Hirshfeld partitioning and charge density localization to express polarizability derivatives as charge flow modulations named Raman bonds. Chemical enhancements can accordingly be explained by Raman bonds near molecule-metal interfaces, and a charge based interpretation is obtained. The Raman bond model is demonstrated to work consistently for different types of molecule-metal bonds, different resonance conditions, and model systems with or without periodic conditions. Model systems consisting of pyridine, thiol, carbene, and CO molecules with localized clusters or periodic slabs are studied at different excitation frequencies and applied electric fields. Various factors such as electric fields, chemical substitutions, molecular structures, excitation frequencies, surface coverages, and surface roughness are consistently explained by Raman bond distributions near molecule-metal interfaces. Stronger chemical enhancements can be achieved by increasing the Raman bond conjugation near molecule-metal interfaces. The Raman bond model also helps quantify different enhancement mechanisms by mapping Raman bonds in the molecule, the inter-fragment bond, and the metal to enhancement contributions of molecular, charge transfer, and plasmon resonance. The mapping interprets EM as charge flow modulations in the metal. Such interpretation of EM may provide insights for building one holistic theory of SERS which includes CM and EM in a full quantum mechanical theory. The Raman bond model also reveals a linear correlation between chemical enhancements and inter-fragment charge flows to the fourth power. Based on the correlation, we show that SERS spectra of localized and periodic systems normalized by inter-fragment charge flows can be unified.

Download or read book Surface Enhanced Raman Scattering written by Richard Chang and published by Springer. This book was released on 2012-11-25 with total page 424 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the course of the development of surface science, advances have been identified with the introduction of new diagnostic probes for analytical characterization of the adsorbates and microscopic structure of surfaces and interfaces. Among the most recently de veloped techniques, and one around which a storm of controversy has developed, is what has now been earmarked as surface enhanced Raman scattering (SERS). Within this phenomenon, molecules adsorbed onto metal surfaces under certain conditions exhibit an anomalously large interaction cross section for the Raman effect. This makes it possible to observe the detailed vibrational signature of the adsorbate in the ambient phase with an energy resolution much higher than that which is presently available in electron energy loss spectroscopy and when the surface is in contact with a much larger amount of material than that which can be tolerated in infrared absorption experiments. The ability to perform vibrational spectroscopy under these conditions would lead to a new understanding about the chemical identity, geome try, and bonding of adsorbed material at a level previously unacces sible. It is for these reasons that the last few years have brought an explosion of activity surrounding the exploitation of SERS. The search for the origines) of the anomalous enhancement has given rise to a research sub-activity of its own. Efforts to explain the en hancement have led to an increased understanding of the whole range of phenomena associated with the interaction of photons with adsor bates and metal surfaces.

Download or read book Metal Surface Raman Spectroscopy Theory written by R. M. Hexter and published by . This book was released on 1978 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt: Studies of the Raman and infrared spectra of several molecules adsorbed to metal surfaces indicate that special selection rules govern these spectra. In the case of infrared reflection adsorption spectroscopy (IRS) as in the related techniques of electron energy loss spectroscopy (ELS) and inelastic electron tunneling spectroscopy (IETS), only modes which develop dipole moment perpendicular to the metal surface can be excited. Both infrared and Raman spectra of oriented metal adsorbates can be used to probe molecular orientation. Depolarization ratios for specific orientations and scattering geometries have been derived and used to analyze the results of several experimental examples. The adsorbed molecule whose Raman spectrum has been most thoroughly studied is pyridine on silver. Using secondary ion mass spectroscopy, we have been able to show that the silver surfaces are atomically quite clean. The case of pyridine adsorbed on Ag is also of interest because of the relative intensity of some of its Raman lines. By comparison with the same lines in liquid pyridine, the intensity is apparently enhanced by a factor of 10000. Several theories of this enhancement are analyzed.