Raman Spectroelectrochemistry of Molecules within Individual Electromagnetic Hot Spots

摘要: The role of chemical enhancement in surface-enhanced Raman scattering (SERS) remains a contested subject. We study SERS spectra 4-mercaptopyridine molecules excited far from the molecular resonance, which are collected individual electromagnetic hot spots at concentrations close to single-molecule limit. created by depositing Tollen’s silver island films on transparent electrode incorporated within an electrochemical cell. Analysis intensity relative those obtained rhodamine 6G same surface provides lower limit ∼3 orders magnitude for enhancement. This large is likely be due charge transfer resonance involving electron metal adsorbed molecule. Excitation three different wavelengths, as well variation potential 0 −1.2 V, lead significant changes intensities bands spectrum. It suggested ...