Selectivity surface-enhanced Raman spectroscopy

Some characteristics of, and comparisons between, surface-enhanced Raman spectroscopy (SERS) and infrared reflection-absorption spectroscopy (IRRAS) for examining reactive as well as stable electrochemical adsorbates are illustrated by means of selected recent results from our laboratory. The differences in vibrational selection rules for surface Raman and infrared spectroscopy are discussed for the case of azide adsorbed on silver, and used to distinguish between "flat" and "end-on" surface orientations. Vibrational band intensity-coverage relationships are briefly considered for some other systems that are unlikely to involve coverage-induced reorientation. 

Section II will discuss the basic phenomena of inelastic tunneling from the viewpoint of the experimentalist. Section III will treat peak shapes, shifts, and widths. Section IV will deal with intensities and selection rules in IETS. Finally, Section V includes some recent applications of IETS to the fields of chemisorption and catalysis, and to the at first glance unrelated field of surface enhanced Raman spectroscopy. 

Chemiluminescence is a very sensitive and selective technique. Reagent types, analytes, and detection limits have been summarized in a review by Imai.56 Chemiluminescence has been applied to the analysis of compounds that exhibit low UV absorbance, including metal ions, amino acids, fatty acids, and bile acids. Other detectors include detectors for radioactivity, nuclear magnetic resonance (NMR), and surface-enhanced Raman spectroscopy. Radioactivity detection is one of the most selective detectors, as only components that have been radiolabeled will be detected. The interface of NMR with HPLC and has been discussed in detail by Grenier-Loustalot et al.57 Surface-enhanced Raman spectroscopy is another technique that... 

J. Creighton, The selection rules for surface-enhanced Raman spectroscopy, in Spectroscopy of Surfaces (R. J. H. Clark and R. E. Hester, eds.), Vol. 16, Chapter 2, p. 37, and references therein. John Wiley, New York, 1988. 

Nabiev IR, Morjani H, Manfait M (1991) Selective analysis of antitumor drug interaction with living cancer cells as probed by surface-enhanced Raman spectroscopy. Eur Biophys J 19 311 Xiao M, Nyagilo J, Arora V, Kulkami P, Xu DS, Sun XK, Dave DP (2010) Gold nanotags for combined multi-colored Raman spectroscopy and x-ray computed tomography. Nanotechnology 21 1-8... 

Zhang X, Shah NC, Duyne RPV (2006) Sensitive and selective chem/bio sensing based on surface-enhanced Raman spectroscopy (SERS). Vib Spectrosc 42 2-8... 

Moskovits M (1982) Surface selection-rules. J Chem Phys 77(9) 4408-4416 Moskovits M, Suh JS (1984) Surface selection-rules for surface-enhanced Raman-spectroscopy - calculations and application to the surface-enhanced Raman-spectrum of phthalazine on silver. J Phys Chem-Us 88(23) 5526-5530... 

Creighton J A 1988 The selection rules for surface-enhanced Raman spectroscopy Spectroscopy of Surfaces ed R J H Clark and R E Hester (Chichester Wiley) pp 37-89... 

Spatial heterogeneity and low reproducibility of surface roughness of the first generation of substrates for the surface-enhanced Raman spectroscopy (SERS) were the basic restrictions of the quantitative description of effect and comparative analysis of data obtained in different laboratories. For this reason SERS spectroscopy, despite of high selectivity and sensitivity, has not got wide application as a routine analytical technique in physical, chemical and biomedical laboratories. 

Abstract Surface analyses have been one of the key technologies for corrosion control and surface finishing. It is very important that the most appropriate apparatus for the purpose of the analyses should be selected from various analytical techniques. In this chapter, surface analytical methods for corrosion control and surface finishing, such as X-ray fluorescence analysis (XRF), X-ray diffraction analysis (XRD), X-ray photo-electron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Auger electron spectroscopy (AES), Secondary ion mass spectrometry (SIMS), Rutherford back-scattering spectrometry (RBS), Surface-enhanced Raman spectroscopy (SERS), Fourier-transform infrared spectroscopy (FTIR), and so on, are briefly introduced. 

The overriding drawback of Raman spectroscopy is that Raman scatter is fundamentally a weak phenomenon. Resonance Raman spectroscopy and surface enhanced Raman spectroscopy (SERS) are two methods which can be exploited in a spectroelectrochemical experiment to enhance the signal and increase the selectivity of the signal. 

From an experimental standpoint, information on the dye binding modes at the semiconductor/dye interface, are conventionally accessed by vibrational spectroscopy [Fourier Transform InfraRed (FT-IR) spectroscopy and Surface-Enhanced Raman Spectroscopy (SERS)] [228-237]. These techniques can provide structural details about the adsorption modes as well as information on the relative orientation of the molecules anchored onto the oxide surface. Photoelectron Spectroscopy (PES) has also been successfully employed to characterize the dye/oxide interface for a series of organic dyes [238-242]. The analysis of the PES spectra yields information on the molecular and electronic structures at the interface, along with basic indications of the dye coverage and of the distance of selected atoms from the... 

The revolution in Raman spectroscopy has been slow to come to the college chemistry classroom and laboratory. Standard undergraduate textbooks attempt to cover modern Raman spectroscopy, but achieve mixed results. Textbooks typically devote far less space to Raman scattering than to infrared absorption. The student is often left with the impression that Raman spectroscopy is an esoteric branch of vibrational spectroscopy, useful only for its selection rules or for measurements in aqueous solution. Almost entirely missing is a sense of excitement over such contemporary topics as Raman microscopy and Raman imaging, ultrasensitive surface-enhanced Raman spectroscopy, or industrial process control, and the many other applications enabled by fiber-optic probes. 

Mulvaney, S.P., et al., Glass-Coated, Analyte-Tagged Nanoparticles A New Tagging System Based on Detection with Surface-Enhanced Raman Scatterintg. Langmuir, (2003). 19(11) p. 4784-4790. Nabiev, I.R., H. Moijani, and M. Manfait, Selective Ananylsis of Antitumor Dmg Interactions with Living Cancer Cells as Probed by Surface-Enhanced Raman Spectroscopy. Eur. Biophys. /, (1991). 19 p. 311-316. 

---