Mapping the Energy Distribution of SERRS Hot Spots from Anti-Stokes to Stokes Intensity Ratios

Abstract

The anomalies in the anti-Stokes to Stokes intensity ratios in single-molecule surface-enhanced resonance Raman scattering were investigated. Brilliant green and crystal violet dyes were the molecular probes, and the experiments were carried out on an electrochemically activated Ag surface. The results allowed new insights into the origin of these anomalies and led to a new method to confirm the single-molecule regime in surface-enhanced Raman scattering. Moreover, a methodology to estimate the distribution of resonance energies that contributed to the imbalance in the anti-Stokes to Stokes intensity ratios at the electromagnetic hot spots was proposed. This method allowed the local plasmonic resonance energies on the metallic surface to be spatially mapped.

The electrochemical reduction of CO2 on a copper electrode in 1-n -butyl-3-methyl imidazolium tetrafluoroborate (BMI.BF4 ) monitored by surface-enhanced Raman scattering (SERS)

“…Since its discovery, SERS has proven to be a powerful technique for the in situ investigation of adsorbates on different metal surfaces, especially on silver, copper, and gold . The SERS technique is extremely sensitive, and it is even capable of detecting surface species at the single molecule level . In this work, SERS method will be employed to characterize the chemical species present on the copper electrode during the CO 2 electrochemical reduction in 1‐ n ‐butyl‐3‐methyl imidazolium tetrafluoroborate (BMI.BF 4 ) RTIL.…”

“…[27] The SERS technique is extremely sensitive, and it is even capable of detecting surface species at the single molecule level. [28,29] In this work, SERS method will be employed to characterize the chemical species present on the copper electrode during the CO 2 electrochemical reduction in 1-n-butyl-3-methyl imidazolium tetrafluoroborate (BMI.BF 4 ) RTIL.…”

Nanoscale Surface Redox Chemistry Triggered by Plasmon‐Generated Hot Carriers

“…In our metal‐SAM‐dye system, carriers must pass through the thiolate SAM to trigger reduction of the dye. In other systems and experiments, charge separation and transfer were found to proceed on a fast timescale, from picoseconds to microseconds . The efficiency of the charge transfer strongly affects the overall quantum yield .…”

“…In other systems and experiments, charge separation and transfer were found to proceed on a fast timescale, from picoseconds [20] to microseconds. [21] The efficiency of the charge transfer strongly affects the overall quantum yield. [22][23][24] Aiming for further confirmation that hot electrons possess the same transfer properties as lower energy electrons, [25,26] we considered two potential charge transfer mechanisms: incoherent, thermally activated hopping, or coherent, nonresonant tunneling (Figure 3).…”

Espalhamento Raman intensificado pela superfície (SERS) no regime de detecção de uma molécula

“…[91,[94][95][96] Inúmeros métodos podem ser aplicados para a resolução deste sistema de equações e nosso grupo tem utilizado o programa desenvolvido por Draine e col. conhecido como DDSCAT. [94,97] que possibilita a escolha do tipo de algorítmo a ser utilizado, como por exemplo, método do gradiente biconjugado [98], que permite obter resultados bastante satisfatórios com custos computacionais relativamente baixos, o qual foi utilizado em todas as simulações DDA nesta tese [99].…”