Colloid SERS spectroscopy

The colloid SERS spectroscopy has a simple experimental pretreatment procedure and the Raman measurements can be carried out with conventional liquid cells or capillaries . 

Tarazona A, Kreisig S, Koglin E and Schwuger M J 1997 Adsorption properties of two cationic surfactant classes on silver surfaces studied by means of SERS spectroscopy and ab initio calculations Prog. Colloid Polym. Sol. 103 181-92... 

Prochazka M., Mojzes P., Stepanek J., Vlckova B., Turpin P.Y., Probing applications of laser ablated Ag colloids in SERS spectroscopy Improvement of ablation procedure and SERS spectral testing, Anal. Chem. 1997 69 5103-5108. 

Muniz-Miranda M, Pergolese B, Bigotto A, Giusti A (2007) Stable and efficient silver substrates for SERS spectroscopy. J Colloid Interface Sci 314 540-544... 

It is well known that the dependence of the SERS bands on the excitation energy can affect the relative intensity ratios, especially in cases where the first-layer effect plays an important role [12]. Consequently, it is crucial to corroborate the indepence of the surfactant SERS spectra from the excitation energy. Unfortunately, it is not possible to examine the CH bands around 3000 1/cm from the C PyBr by means of NIR FT-SERS spectroscopy [33]. As an alternative to overcome this drawback silver colloids were used. The laser beam was focused onto the sample cell and collected in backscatter-ing configuration, using conventional optics instead of a microscope to improve the signal to noise ratio. 

This type of SERS spectroscopy also requries a potentiostat to maintain the potential of the working electrode and a function generator to programme the oxidation-reduction cycles. Metal colloids, which can be prepared by chemical reduction of metal salts [73], are frequently used substrates for SERS experiments. This type of SERS spectroscopy is performed with a conventional Raman cell for liquids, or with capillary tubes. 

X 10 g in 100 g H2O). However, vibration spectra of these molecules have been obtained by means of colloid-surface-enhanced Raman spectroscopy (Colloid-SERS)3 6. 

Neddersen, J., Chumanov, G. and Cotton, T.M. (1993) Laser ablation of metals-a new method for preparing SERS active colloids. Applied Spectroscopy, 47,... 

SERS. A phenomenon that certainly involves the adsorbent-adsorbate interaction is that of surface-enhanced resonance Raman spectroscopy, or SERS. The basic observation is that for pyridine adsorbed on surface-roughened silver, there is an amazing enhancement of the resonance Raman intensity (see Refs. 124—128). More recent work has involved other adsorbates and colloidal... 

Plenary 3. Ronald E Hester et al, e-mail address reh York.ac.uk (SERS). Use of dioxane envelope to bring water insoluble cliromophores (chlorophylls) into contact with aqueous silver colloids for SERS enliancement. PSERRS— protected surface-enhanced resonance Raman spectroscopy . 

The sensitivity limitations of TLC-FT-Raman spectroscopy may be overcome by applying the SERS effect [782]. Unlike infrared, a major gain in Raman signal can be achieved by utilising surface activation and/or resonance effects. Surface-enhanced Raman (SER) spectra can be observed for compounds adsorbed on (rough) metahic surfaces, usually silver or gold colloids [783,784], while resonance Raman (RR) spectra... 

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... 

Leverette, C.L. and Dluhy, R.A. (2004) Vibrational characterization of a planar-supported model bilayer system utilizing surface-enhanced Raman scattering (SERS) and infrared reflection-absorption spectroscopy (IRRAS). Colloids and Surfaces A, 243, 157-167. 

Compared with normal Raman spectroscopy, the SERS technique gives a considerably lower limit of determination of the substance to be analyzed. This is achieved by bringing colloidal noble metal atoms into close proximity to the sample molecules after they have been separated by TLC. Further information can he found in [90, 91]. 

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