Fleischmann, surface enhanced Raman

In most work on electrochemical systems, use is made of two effects that greatly enhance the Raman signals. One is resonance Raman spectroscopy (RRS), wherein the excitation wavelength corresponds to an electronic transition in an adsorbed molecule on an electrode surface. The other effect is surface-enhanced Raman spectroscopy (SERS), which occurs on certain surfaces, such as electrochemically roughened silver and gold. This effect, discovered by Fleischmann et al. (1974), yields enhancements of 10 to 10 . The vast majority of publications on Raman studies of electrochemical systems use SERS. The limitations of SERS are that it occurs on only a few metals and the mechanism of the enhancement is not understood. There is speculation that only a small part of the surface is involved in the effect. There is a very good review of SERS (Pemberton, 1991). 

Several variations of Raman spectroscopy have been developed with the purpose of enhancing the sensitivity [surface-enhanced Raman spectroscopy (SERS)], improving the spatial resolution (micro-Raman spectroscopy), or acquiring very specific information (resonance Raman spectroscopy) (Laserna, 1996). Specifically, SERS (Fleischmann et al., 1974) is normally done in a silver or gold colloid or a... 

Surface-enhanced Raman scattering was first observed by Fleischmann, et al. (3) for pyridine adsorbed on a silver surface that had been roughened by repeated electrochemical oxidation and reduction in chloride solution. The... 

Surface-enhanced Raman spectroscopy (S S) has been a focus for much study since it was first reported by Fleischmann and coworkors in 1976 (10). Thus far, a considoable amount of this work has been aimed at undostanding the physical origin of the phenomenon (10-13), but recently there have been many investigations of potential analytical uses for SERS (14-18). Although it has not yet come into general use, SERS is an attractive analytical technique that can detect certain types of molecules with a high level of sensitivity. Furthermore, because SERS is a vibrational spectroscopy, a SER spectrum contains a lot of molecular information. 

Fleischmann, M., HUl, I.R. and Robinson, J. (1983) Surface-enhanced Raman scattering from silver electrodes Potential and cation dependences of the very low frequency mode. Chemical Physics Letters, 97,441. 

Fleischmann, M., Sockalingum, D. and Musiani, M.M. (1990) The use of near-infrared Fourier transform techniques in the study of surface-enhanced Raman spectra. Spectrochimica Acta Part A, 46A, 285. 

Fleischmann, M. and Hill, I.R. (1983) The observation of solvated metal ions in the double layer region at silver electrodes using surface enhanced Raman scattering. Journal of Electroanalytical Chemistry, 146, 367-376. 

Fleischmann, M., Hill, I.R., Mengoli, G. et al. (1985) A comparative study of the efficiency of some organic inhibitors for the corrosion of copper in aqueous chloride media using electrochemical and surface-enhanced Raman scattering techniques. Electrochimica Acta, 30, 879-888. 

One of the most important tasks of modern electrochemistry is to develop microscopic pictures of solid-liquid interfaces and thus to provide a basis for the detailed understanding of electrochemical processes. To fulfill this task, the development of surface-specific and structure-sensitive in-situ methods to characterize electrochemical interfacial processes is indispensable. As early as 1970, Professor Martin Fleischmann was one of the pioneers in exploring in-situ methods that included surface-enhanced Raman spectroscopy [1], surface X-ray diffraction [2] and nuclear magnetic resonance [3] to characterize electrochemical interfaces. Nowadays, nontraditional electrochemical methods that include spectroscopic and microscopic as well as diffraction techniques have been extensively applied, and this has promoted an understanding of electrochemical interfaces at both atomic and molecular levels. 

The first in-situ X-ray diffraction (XRD) investigations of phase transitions of adsorbed monolayers and multilayers [6] and reconstmction of a metal surface [7,8] were also reported by Fleischmann and Mao. The phase transitions were reported for the underpotential deposition (upd) and overpotential deposition (opd) of thallium onto a roughened silver electrode surfaces (similar to those used in surface-enhanced Raman spectroscopy (SERS) using the reflection mode of collection), and for upd of lead onto gold and silver... 

Over the past decades, smface enhanced Raman scattering (SERS) has became a valuable spectroscopic technique as a powerful smface diagnostic tool. In 1974 Fleischmann, Hendra, and McQuillan performed the first measurement of a surface Raman spectrum from pyridine adsorbed on an electrochemically roughened silver electrode. It has been explained that some vibrational bands of pyridine are selectively enhanced a million times. This increases the sensitivity of... 

Crookell, A., Fleischmann, M., Hanniet, M. and Hendra, PJ. (1988) Surface enhanced Fourier transform Raman spectroscopy in the near infrared. Chemical Physics Letters, 149,123. 

The discovery of a particular enhancement effect (up to 10 ) that affects only species in close contact with the metal electrode surface (i.e. adsorbed species) by Fleischmann et al. [352] and slightly later by Jeanmaire et al. [353] and a report on the utilization of resonance enhancement in surface Raman spectroscopy [354] demonstrated surprisingly the feasibility of vibrational studies of electrochemical... 

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