Single-Particle Photoluminescence and Dark-Field Scattering during Charge Density Tuning

Single-particle spectroelectrochemistry provides optical insight into under-standing physical and chemical changes occurring on the nanoscale. While changes in dark -field scattering during electrochemical charging are well understood, changes to the photoluminescence of plasmonic nanoparticles under similar conditions are less studied. Here, we use correlated single-particle photoluminescence and dark-field scattering to compare their plasmon modulation at applied potentials. We find that changes in the emission of a single gold nanorod during charge density tuning of intraband photoluminescence can be attributed to changes in the Purcell factor and absorption cross section. Finally, modulation of interband photoluminescence provides an additional constructive observable, giving promise for establishing dual channel sensing in spectroelectrochemical measurements.

Automated summary

Single-particle spectroelectrochemistry is a valuable technique for studying physical and chemical changes on the nanoscale. In this study, the changes in photoluminescence and dark-field scattering of plasmonic nanoparticles under applied potentials were compared. The results showed that the modulation of intraband photoluminescence was attributed to changes in the Purcell factor and absorption cross section. Moreover, modulation of interband photoluminescence showed promise for dual channel sensing in spectroelectrochemical measurements.