Surface-enhanced Raman spectroscopy (SERS) on silver colloids for the identification of ancient textile dyes. Part II: pomegranate and sumac

2011 ◽  
Vol 42 (3) ◽  
pp. 465-473 ◽  
Author(s):  
Silvia Bruni ◽  
Vittoria Guglielmi ◽  
Federica Pozzi ◽  
Anna Maria Mercuri
Keyword(s):  
Raman Spectroscopy ◽  
Surface Enhanced Raman Spectroscopy ◽  
Textile Dyes ◽  
Silver Colloids ◽  
Surface Enhanced ◽  
Surface Enhanced Raman

FT Surface-Enhanced Raman Evidence of the Oxidative Condensation Reactions of Caffeic Acid in Solution and on Silver Surface

2000 ◽  
Vol 54 (2) ◽  
pp. 230-238 ◽  
Author(s):  
S. Sánchéz-Cortés ◽  
J. V. García-Ramos
Keyword(s):  
Raman Spectroscopy ◽  
Caffeic Acid ◽  
Surface Enhanced Raman Spectroscopy ◽  
Oxidation Products ◽  
Fluorescence Signal ◽  
Additional Advantage ◽  
Silver Colloids ◽  
Surface Enhanced ◽  
Surface Enhanced Raman

Fourier transform (FT)-Raman spectroscopy and FT surface-enhanced Raman spectroscopy (FT-SERS) are applied for the first time to study the chemical oxidative changes undergone by caffeic acid (CA) in solution and when adsorbed on silver colloids. UV-visible spectroscopy was also applied to follow the polymerization of CA. Normal Raman techniques have only a limited application in the characterization of CA oxidation products owing to the high fluorescence background emitted by them. Nevertheless, the use of silver colloids may both quench the fluorescence signal and catalyze the CA oxidation, with the additional advantage of analyzing very small concentrations of the CA derivatives formed in situ on the surface. The influence of the solvent (water or ethanol) in the oxidation of the stock solution, the pH, and the storage time on the SERS spectra was investigated and analyzed on the basis of the oxidation and polymerization mechanisms proposed by several authors in the literature. The results found for CA were compared with those for other chemically related molecules as catechol and isoferulic acid in order to assign the vibrational spectra obtained at the different conditions employed to carry out the study of CA oxidation. The results found in this study demonstrate that the polymerization mechanism followed by CA depends on the conditions of CA storage and those at which the SERS spectra are recorded. The conclusions derived from this work can be very useful in the understanding of the chemical processes undergone by CA, which lead to possible changes in the nutritional value of the foods where this molecule appears. The advantage of this technique in relation to those employed so far in similar investigations is the ability to carry out in situ time-resolved measurements, thus allowing assignments of the different mechanisms of CA oxidation under the different experimental conditions employed.

Surface-enhanced Raman spectroscopy of ellipticines adsorbed onto silver colloids

1992 ◽  
Vol 96 (2) ◽  
pp. 926-931 ◽  
Author(s):  
G. Levi ◽  
J. Pantigny ◽  
J. P. Marsault ◽  
D. H. Christensen ◽  
O. Faurskov Nielsen ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Surface Enhanced Raman Spectroscopy ◽  
Silver Colloids ◽  
Surface Enhanced ◽  
Surface Enhanced Raman

Analytical Potential of Surface-Enhanced Fourier Transform Raman Spectroscopy on Silver Colloids

1993 ◽  
Vol 47 (8) ◽  
pp. 1192-1197 ◽  
Author(s):  
E. Wentrup-Byrne ◽  
S. Sarinas ◽  
P. M. Fredericks
Keyword(s):  
Raman Spectroscopy ◽  
Near Infrared ◽  
Surface Enhanced Raman Spectroscopy ◽  
Preparative Method ◽  
Analytical Tool ◽  
Silver Colloids ◽  
Fourier Transform Raman Spectroscopy ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Ft Raman

Although FT-Raman is becoming an increasingly popular analytical tool, it has proved to be relatively insensitive for the analysis of solutions. This is a serious problem, particularly for studies in the biochemical area. Because resonance Raman is not available for near-infrared excitation, surface-enhanced Raman spectroscopy (SERS) provides an important pathway to improved sensitivity. This study is concerned with assessing the potential of SERS with FT-Raman as an analytical tool for aqueous solutions. The SERS effect was investigated for a variety of organic molecules, both nitrogen and non-nitrogen containing, with silver colloids prepared by different literature methods. Various factors were studied: the effect of colloid preparative method, age of the colloid, addition of potassium chloride, time after addition of analyte, and concentration of analyte. In some cases, an analyte gave no SERS effect with a particular colloid, but exhibited a large SERS effect with a colloid prepared by a different method.

ChemInform Abstract: Surface-Enhanced Raman Spectroscopy of Ellipticines Adsorbed onto Silver Colloids.

ChemInform ◽  
2010 ◽  
Vol 23 (22) ◽  
pp. no-no
Author(s):  
G. LEVI ◽  
J. PANTIGNY ◽  
J. P. MARSAULT ◽  
D. H. CHRISTENSEN ◽  
O. F. NIELSEN ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Surface Enhanced Raman Spectroscopy ◽  
Silver Colloids ◽  
Surface Enhanced ◽  
Surface Enhanced Raman
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