When photoexcited, plasmons decay through multiple pathways including surface scattering and photoluminescence. Spectroscopic investigation at the single-particle level can provide insight to these decay pathways. The plasmon’s spectral response is sensitive to changes in dielectric environment, charge density, and chemical conformations that can be tuned <i>in situ</i>. Electrochemical experiments coupled with dark-field spectroscopy have been shown by our group and others to report on anodic and cathodic charging at the single-particle level, revealing heterogeneity in charge transfer at nanostructured electrodes. While changes in dark-field spectroscopy during the application of charge is well understood, few studies have investigated changes to the photoluminescence of plasmonic nanoparticles under electrochemical charging. We use correlated single-particle photoluminescence and dark-field scattering to determine if light emission after photoexcitation acts as an antenna to the same changes observed in scattering or if photoluminescence can provide unique insight into the effect of electrochemical charging on the longer lived light emission process. By monitoring changes to interband photoluminescence at different potentials, charge transfer dynamics between the AuNR and indium tin oxide working electrode support are also explored. Once the mechanism of electrochemical induced changes to the photoluminescence of plasmonic nanoparticles is fully understood this technique may offer promise in establishing increased sensitivity to traditional scattering spectroelectrochemical measurements.

Single-particle photoluminescence and scattering spectroscopy of AuNRs during electrochemical charge density tuning

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.