Quantum Nature of Plasmon-Enhanced Raman Scattering

We report plasmon-enhanced Raman scattering in graphene coupled to a single plasmonic hotspot measured as a function of laser energy. The enhancement profiles of the G peak show strong enhancement (up to $10^5$) and narrow resonances (30 meV) that are induced by the localized surface plasmon of a gold nanodimer. We observe the evolution of defect-mode scattering in a defect-free graphene lattice in resonance with the plasmon. We propose a quantum theory of plasmon-enhanced Raman scattering, where the plasmon forms an integral part of the excitation process. Quantum interferences between scattering channels explain the experimentally observed resonance profiles, in particular, the marked difference in enhancement factors for incoming and outgoing resonance and the appearance of the defect-type modes.Comment: Keywords: plasmon-enhanced Raman scattering, SERS, graphene, quantum interferences, microscopic theory of Raman scattering. Content: 22 pages including 5 figures + 11 pages supporting informatio

Surface enhanced Raman scattering

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Carbon nanotube chirality determines properties of encapsulated linear carbon chain

Long linear carbon chains encapsulated inside carbon nanotubes are a very close realization of carbyne, the truly one-dimensional allotrope of carbon. Here we study individual pairs of double-walled carbon nanotubes and encapsulated linear carbon chains by tip-enhanced Raman scattering. We observe that the radial breathing mode of the inner nanotube correlates with the frequency of the carbon chain's Raman mode, revealing that the nanotube chirality determines the vibronic and electronic properties of the encapsulated carbon chain. We provide the missing link that connects the properties of the encapsulated long linear carbon chain with the structure of the host nanotube.Comment: keywords: linear carbon chains; carbyne; carbon nanotubes; tip-enhanced Raman scattering; TERS; Significant changes compared to first version of the manuscript. Current version includes Supporting Informatio

Surface-Enhanced Raman Scattering

The steady and fast development of surface and interfacial science have set up innovative openings for new diagnostic probes for analytical characterization of the adsorbates and determination of the microscopic structure of surfaces and interfaces. Regrettably Raman spectroscopy, being a weak scattering surface phenomenon, had seized no part in it, until the discovery and development of Surface Enhanced Raman Scattering (SERS) in the early 1970’s that has opened up broad research fields both in the physics and chemistry of interfaces. The discovery of SERS by Fleischmann and coworkers in 1974 at the University of Southampton, United Kingdom is closely connected with the electrochemical systems. They reported an extraordinary million-fold enhancement of weak Raman signal from pyridine molecules adsorbed onto electrochemically roughened silver electrode compared to that from free molecules in liquid environment. In early 1976, Richard P. Van Duyne and David Jeanmaire at Northwestern University observed the effect and in early 1977, M. G. Albrecht and J. A. Creighton reported similar observation. This review article deals with the development of SERS research with special importance is given to the fabrication of various SERS-active substrates, mechanism of SERS effect and its various potential applications ranging from sensors to biomedical applications

Asphaltene detection using Surface Enhanced Raman Scattering (SERS)

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Present and future of surface-enhanced Raman scattering

The discovery of the enhancement of Raman scattering by molecules adsorbed on nanostructured metal surfaces is a landmark in the history of spectroscopic and analytical techniques. Significant experimental and theoretical effort has been directed toward understanding the surface-enhanced Raman scattering (SERS) effect and demonstrating its potential in various types of ultrasensitive sensing applications in a wide variety of fields. In the 45 years since its discovery, SERS has blossomed into a rich area of research and technology, but additional efforts are still needed before it can be routinely used analytically and in commercial products. In this Review, prominent authors from around the world joined together to summarize the state of the art in understanding and using SERS and to predict what can be expected in the near future in terms of research, applications, and technological development. This Review is dedicated to SERS pioneer and our coauthor, the late Prof. Richard Van Duyne, whom we lost during the preparation of this article

The next generation of advanced spectroscopy : surface enhanced raman scattering from metal nanoparticles

Surface enhanced Raman scattering (SERS) has enjoyed an ever growing research base since its discovery with the number of papers published using the technique and investigating the basis behind it growing exponentially year by year.[1] SERS is an advancement of Raman scattering which overcomes some of the limitations of normal Raman scattering. Raman scattering is a vibrational spectroscopy which gives molecularly specific information relating to specific molecular species. The disadvantage of Raman scattering is that it is an inherently weak process, however it can be used in aqueous solutions, due to water being a weak Raman scatterer, lending itself to analysis and study of molecules in aqueous solution including the study of biomolecules. Another major disadvantage is the fluorescence which often accompanies Raman scattering and can sometimes overwhelm the bands in the spectrum rendering the experiment useless. To overcome this, the phenomenon of surface enhanced Raman scattering can be used

Local protonation control using plasmonic activation

Localized protonation of 4-mercaptopyridine (4-MPY), activated by light in the presence of silver nanoparticles is monitored under ambient conditions using surface-enhanced Raman scattering (SERS) and tip-enhanced Raman scattering (TERS). The reaction can be controlled by the excitation wavelength and the atmospheric conditions, thus, providing a tool for site-specific control of protonation

Two small-volume electrochemical cells for the measurement of surface enhanced Raman scattering

Two electrochemical cells, for performing surface enhanced Raman scattering (SERS), with submillilitre volumes are presented. One of the cells is especially developed for use in a Raman microspectrometer. The smallest cell uses only 80 mu l of sample. SER measurements are performed on 2*10-3 M adenine