The plasmon interacts with its molecular environment both as a donor of charge and energy, as well as an antenna that acts as a sensor or amplifies spectroscopic signals. Molecular signals can be enhanced enough to enable the detection of single molecules, while the plasmon itself is sensitive to follow electrochemical charging, changes in adsorbed ions, and redox chemistry.  Achieving significant mechanistic insights into the interactions at the plasmonic-soft materials interface that drives efficient local (electro-)chemistry or sensing performance requires a single-particle approach to eliminate inhomogeneous averaging due to different nanostructure geometries.

To address the limitations of ensemble spectroscopy, the Link Research Group is employing and developing novel spectro-electrochemical methods to follow energy transfer at the interface of plasmonic-polymeric heterostructures, as well as charge injection of electrons into the surrounding solvent. The overall goal is to achieve mechanistic insights into the principles governing efficient and selective plasmon-enhanced redox chemistry at soft interfaces. These sensing studies are also extended to soft interfaces with proteins bound to the nanoparticle surface forming a protein corona that we aim to characterize using the plasmon as a sensitive read-out of binding or conformation. Our current emphasis is on the following topics: Plasmon-coupled circular dichroism, single-particle spectro-electrochemistry, and plasmon-enhanced solvated electron generation.