Surface-enhanced Raman scattering in local optical fields of silver and gold nanoaggregates-from single-molecule Raman spectroscopy to ultrasensitive probing in live cells.
This Account discusses surface-enhanced Raman scattering at extremely high enhancement levels that can occur for molecules attached to silver and gold nanoclusters. Strongly enhanced and highly confined local optical fields enable surface-enhanced Stokes and anti-Stokes Raman spectroscopy of single molecules even under nonresonant excitation conditions as well as extremely large effective cross sections in two-photon excited Raman spectroscopy. The ability for very sensitive and spatially confined molecular structural probing makes gold and silver nanoclusters very promising tools for studies of small structures in biological materials, such as cellular compartments.
Kneipp
Katrin
K
Wellman Center for Photomedicine, Harvard University Medical School, Boston Massachusetts 02114, USA. kneipp@usa.net
Kneipp
Harald
H
Kneipp
Janina
J
D002477:Cells; D006046:Gold / Q000737:chemistry*; D053768:Metal Nanoparticles; D015335:Molecular Probes; D012680:Sensitivity and Specificity; D012834:Silver / Q000737:chemistry*; D013059:Spectrum Analysis, Raman / Q000379:methods*; D013499:Surface Properties
D015335:Molecular Probes; D012834:Silver; D006046:Gold