Jump to main content
Jump to site search
Access to RSC content Close the message box

Continue to access RSC content when you are not at your institution. Follow our step-by-step guide.

Volume 132, 2006
Previous Article Next Article

Practical control of SERRS enhancement

Author affiliations


The demonstration that quantitative and sensitive analysis can be carried out using surface enhanced resonance Raman scattering (SERRS) prompted a discussion and investigation of the main variables which are within the control of the analyst using colloidal silver as the substrate. Previous papers have dealt with the crucial need to obtain good chemisorption of the analyte to the surface and have reported the use of specially designed dyes for SERRS. One of the most variable processes is the aggregation of the colloid. Here, we investigate the addition of controlled amounts of an organic aggregating agent, poly-L-lysine, at concentrations which reduce the zeta potential in a controlled manner, thus aiding aggregation control. The relationship between the excitation frequency, the surface plasmon resonance frequency of the silver colloid and the frequency of the maximum absorbance of the molecular chromophore is studied using low concentrations of dye and no aggregating agent. Under these conditions, little to no aggregation is expected. The magnitude of the enhancement is strongly dependent on the frequency of the molecular chromophore as well as the plasmon resonance frequency. However, when sodium chloride is used to aggregate the colloid, a larger enhancement is obtained and the strong dependence on the molecular chromophore largely disappears. A much broader enhancement profile is obtained which appears to be related more to the specific enhancement processes caused by aggregation than the frequency of the chromophore. However, the total enhancement for SERRS is higher than for SERS thus indicating that the chromophore is still important to the process.

Back to tab navigation

Article information

04 May 2005
25 May 2005
First published
10 Nov 2005

Faraday Discuss., 2006,132, 135-145
Article type

Practical control of SERRS enhancement

D. Cunningham, R. E. Littleford, W. E. Smith, P. J. Lundahl, I. Khan, D. W. McComb, D. Graham and N. Laforest, Faraday Discuss., 2006, 132, 135
DOI: 10.1039/B506241A

Social activity

Search articles by author