Back to Search Start Over

Near-field surface-enhanced Raman imaging of dye-labeled DNA with 100-nm resolution

Authors :
Deckert, Volker
Zeisel, Dieter
Zenobi, Renato
Source :
Analytical Chemistry. July 1, 1998, Vol. 70 Issue 13, p2646, 5 p.
Publication Year :
1998

Abstract

Raman chemical imaging on a scale of 100 nm is demonstrated for the first time. This is made possible by the combination of scanning near-field optical microscopy (SNOM or NSOM) and surface-enhanced Raman scattering (SERS), using brilliant cresyl blue (BCB)-labeled DNA as a sample. SERS substrates were produced by evaporating silver layers on Teflon nanospheres. The near-field SERS spectra were measured with an exposure time of 60 s and yielded good signal-to-noise ratios (25:1). The distinction between reflected light from the excitation laser and Raman scattered light allows the local sample reflectivity to be separated from the signal of the adsorbed DNA molecules. This is of general importance to correct for topographic coupling that often occurs in near-field optical imaging. The presented data show a lateral dependence of the Raman signals that points to special surface sites with particularly high SERS enhancement.

Details

ISSN :
00032700
Volume :
70
Issue :
13
Database :
Gale General OneFile
Journal :
Analytical Chemistry
Publication Type :
Academic Journal
Accession number :
edsgcl.20947325