A scheme for detecting every single target molecule with surface-enhanced Raman spectroscopy.
Idioma
en
Article de revue
Este ítem está publicado en
Nano Letters. 2011, vol. 11, n° 11, p. 5013-5019
American Chemical Society
Resumen en inglés
Surface-enhanced Raman spectroscopy (SERS) is now a well-established technique for the detection, under appropriate conditions, of single molecules (SM) adsorbed on metallic nanostructures. However, because of the large ...Leer más >
Surface-enhanced Raman spectroscopy (SERS) is now a well-established technique for the detection, under appropriate conditions, of single molecules (SM) adsorbed on metallic nanostructures. However, because of the large variations of the SERS enhancement factor on the surface, only molecules located at the positions of highest enhancement, so-called hot-spots, can be detected at the single-molecule level. As a result, in all SM-SERS studies so far only a small fraction, typically less than 1%, of molecules are actually observed. This complicates the analysis of such experiments and means that trace detection via SERS can in principle still be vastly improved. Here we propose a simple scheme, based on selective adsorption of the target analyte at the SERS hot-spots only, that allows in principle detection of every single target molecule in solution. We moreover provide a general experimental methodology, based on the comparison between average and maximum (single molecule) SERS enhancement factors, to verify the efficiency of our approach. The concepts and tools introduced in this work can readily be applied to other SERS systems aiming for detection of every single target molecule.< Leer menos
Palabras clave en inglés
Surface-enhanced Raman spectroscopy
Single molecule detection
Plasmonics
Site-selective adsorption
CTAB bilayer
Bianalyte SERS
Orígen
Importado de HalCentros de investigación