Near-infrared excited surface-enhanced Raman spectroscopy of rhodamine 6G on colloidal silver

✍ Scribed by K. Kneipp; E. Roth; C. Engert; W. Kiefer

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 453 KB
• Volume: 207
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(93)89028-g

✦ Synopsis

nm excited surface-enhanced Raman spectmsmpy (SERS) of rhodamine 6G (Rb 6G) on NaCl-activated silver sol is reported performed with a scanniug Raman spectrometer. The present study gives the opportunity to compare directly the enhancement factors for excitation in the near-infrared (NIR) and in the visible region and shows that for the case of Rh 6G these factors are of the same order of magnitude. This result can be explained by a growing electromagnetic contribution to theenhaucement at 1064 nm which compensates the loss of resonance Raman enhancement by the change of excitation wavelength from about 500 to 1064 MI. An additional enhancement factor ascribed to the local mechanism of a Rh 6G-adatom-anion surface complex gives an essential contribution to SERS. This specitic enhancement due to Cl-activated sites results in similar contributions in the visible and in the MR.