Re‐examination of the adsorption and reduction processes of thiosemicarbazide at a silver electrode: SERS, UV–visible and capillary electrophoresis studies

Andrade, Gustavo F. S.; Micke, Gustavo Amadeu; Tavares, Marina Franco Maggi; Temperini, Márcia L. A.

doi:10.1002/jrs.1242

Cited by 11 publications

(7 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Bianalyte experiments are accepted as an experimental tool capable of determining the concentration regime at which SM-SERS is observed. − It is then of interest to characterize how the pdf resulting from multiple adsorbed molecules deviates from eq (which is valid for only one adsorbed molecule) when molecule numbers are commensurate with SM-SERS concentrations determined in a bianalyte experiment. To do so we considered the pdf for m molecules distributed on the surface of 1000 HSs described by k̅ , , and σ L M and conducted a bianalyte-like simulation with hypothetical isotopologue molecules (mol1 and mol2) at equal concentrations that were randomly placed onto the model substrate.…”

Section: Resultsmentioning

confidence: 99%

“…6,23,43 In order to further illustrate the utility of the TPMD approach, we analyzed an experimental SM-SERS data set involving rhodamine 6G (R6G) molecules adsorbed onto a rough Ag electrode [roughened by oxidation−reduction cycles (ORCs)]. 44 Normalized histograms of SERS intensities for the 1500 cm −1 band of R6G at different concentrations (Figure 3) were constructed by binning the data into 50 equally spaced bins, with zero SERS intensity events being discarded. The error bars in the histograms of Figure 3 are the standard deviation of a binomial distribution for the number of counts in each bin.…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Evaluation of Surface-Enhanced Raman Spectroscopy Substrates from Single-Molecule Statistics

Kiefl

Santos

et al. 2017

J. Phys. Chem. C

View full text Add to dashboard Cite

Accurate quantification of substrate characteristics is a central pursuit within the field of surface-enhanced Raman spectroscopy (SERS). A theory based on single-molecule SERS (SM-SERS) statistics was developed for comprehensive substrate evaluation. This approach is applicable to general substrates possessing many hotspots and is capable of quantifying hotspot strength variation using a minimal set of fitting parameters. The model was validated for simulated substrates and then applied to the SM-SERS statistics of a roughened silver electrode, for which the degree of hotspot uniformity was quantified. The fitted model parameters provide important information concerning the structure–activity relationship of hotspots and can be used to directly compare SERS substrates. Overall, our results present an experimentally determinable parameter set that potentially improves upon the widely used “average enhancement factor” metric currently used for SERS substrate evaluation.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Evaluation of Surface-Enhanced Raman Spectroscopy Substrates from Single-Molecule Statistics

Kiefl

Santos

et al. 2017

J. Phys. Chem. C

View full text Add to dashboard Cite

show abstract

“…The reference and auxiliary electrodes were Ag|AgCl|KCl (sat) and a platinum wire, respectively. The details of the ORC procedure are well described elsewhere . Briefly, the working electrode was submitted to 3 cycles of oxidation and reduction in the range of potentials between −0.3 and +0.3 V at a scan rate of 50 mV·s –1 .…”

Section: Methodsmentioning

confidence: 99%

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

2012

Self Cite

View full text Add to dashboard Cite

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.

show abstract

“…The SERS experiments were realized using an electrochemically roughened Ag electrode (ER-Ag) as SERS substrate. The ER-Ag electrode was prepared by applying three oxidation−reduction cycles (ORCs) to a freshly polished Ag electrode in 0.1 M KCl solution . The roughening of the Ag electrode was performed in the absence of the analyte (R6G or CR), which was introduced subsequently to the solution up to the desired concentration.…”

Section: Methodsmentioning

confidence: 99%

“…The ER-Ag electrode was prepared by applying three oxidation-reduction cycles (ORCs) to a freshly polished Ag electrode in 0.1 M KCl solution. 35 The roughening of the Ag electrode was performed in the absence of the analyte (R6G or CR), which was introduced subsequently to the solution up to the desired concentration. The average SERS enhancement factor obtained from ER-Ag is about 10 6 .…”

Section: Sers Measurementsmentioning

confidence: 99%

Electrochemical Control of the Time-Dependent Intensity Fluctuations in Surface-Enhanced Raman Scattering (SERS)

et al. 2009

Self Cite

View full text Add to dashboard Cite

Time-dependent fluctuations in surface-enhanced Raman scattering (SERS) intensities were recorded from a roughened silver electrode immersed in diluted solutions of rhodamine 6G (R6G) and congo red (CR). These fluctuations were attributed to a small number of SERS-active molecules probing regions of extremely high electromagnetic field (hot spots) at the nanostructured surface. The time-dependent distribution of SERS intensities followed a tailed statistics at certain applied potentials, which has been linked to single-molecule dynamics. The shape of the distribution was reversibly tuned by the applied voltage. Mixtures of both dyes, R6G and CR, at low concentrations were also investigated. Since R6G is a cationic dye and CR is an anionic dye, the statistics of the SERS intensity distribution of either dye in a mixture were independently controlled by adjusting the applied potential. The potential-controlled distribution of SERS intensities was interpreted by considering the modulation of the surface coverage of the adsorbed dye by the interfacial electric field. This interpretation was supported by a two-dimensional Monte Carlo simulation that took into account the time evolution of the surface configuration of the adsorbed species and their probability to populate a hypothetical hot spot. The potential-controlled SERS dynamics reported here is a first step toward the spectroelectrochemical investigation of redox processes at the single-molecule level by SERS.

show abstract

Re‐examination of the adsorption and reduction processes of thiosemicarbazide at a silver electrode: SERS, UV–visible and capillary electrophoresis studies

Cited by 11 publications

References 31 publications

Evaluation of Surface-Enhanced Raman Spectroscopy Substrates from Single-Molecule Statistics

Evaluation of Surface-Enhanced Raman Spectroscopy Substrates from Single-Molecule Statistics

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

Electrochemical Control of the Time-Dependent Intensity Fluctuations in Surface-Enhanced Raman Scattering (SERS)

Contact Info

Product

Resources

About