Electronic properties of metal nanorods probed by surface-enhanced Raman spectroscopy

Applying the probe molecule strategy, surface-enhanced Raman spectroscopy has been used, for the first time, as a diagnostic tool of the electronic properties of metal nanorods; the vibrational frequency of the probe molecule SCN- at Cu nanorods is shown to critically depend on the nanorod's diameter in the range from 50 to 15 nm; the up-shifting of the Fermi level with a decrease of the nanorod's diameter is interpreted based on the change of cohesive energy owing to the high ratio of surface to bulk atoms.