Towards quantitative surface enhanced resonance Raman scattering (SERRS): a study of aggregation and concentration for two rhodamine dyes
✍ Scribed by C. Rodger; V. Rutherford; P. C. White; W. E. Smith
- Publisher
- John Wiley and Sons
- Year
- 1998
- Tongue
- English
- Weight
- 209 KB
- Volume
- 29
- Category
- Article
- ISSN
- 0377-0486
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✦ Synopsis
A study of the e †ect of concentration of dye and of the conditions of aggregation for surface enhanced resonance Raman scattering (SERRS) from rhodamine 3B and 3G adsorbed on silver colloid indicates that quantitative results can be obtained provided that the concentration of the dye on the colloid surface is kept well below monolayer coverage. There are no interferences due to other adsorbates because of the predominance of the scattering from the chromophore. In addition, Ñuorescence is quenched and low excitation powers are required. The signals are stable for at least 1 h and the RSDs are in the range 6-11% depending on the aggregation method. The preferred method of aggregation is to use as an aggregating agent poly(L-lysine) with ascorbic acid because poly(L-lysine) increases the control over the process. At concentrations equivalent to surface coverage above about one tenth of a monolayer, the dependence of signal on concentration is complex owing to changes in the packing and orientation of the dye at the surface and to multi-layer e †ects.