Investigating Nanoscale Electrochemistry with Surface- and Tip-Enhanced Raman Spectroscopy

• DOI: 10.1021/acs.accounts.6b00327
• Publication Date: 2016-09-07T18:35:36Z
• Authors: Stephanie Zaleski; Andrew J. Wilson; Michael Mattei; Xu Chen; Guillaume Goubert; M. Fernanda Cardinal; Katherine A. Willets; Richard P. Van Duyne
• Keywords: Surface-Enhanced Raman Spectroscopy

The chemical sensitivity of surface-enhanced Raman spectroscopy (SERS) methodologies allows for the investigation heterogeneous reactions with high sensitivity. Specifically, SERS are well-suited to study electron transfer (ET) reactions, which lie at heart numerous fundamental processes: electrocatalysis, solar energy conversion, storage in batteries, and biological events such as photosynthesis. Heterogeneous ET commonly monitored by electrochemical methods cyclic voltammetry, observing billions per second. Since first proof detecting single molecules redox cycling, there has been growing interest examining electrochemistry nanoscale single-molecule levels. Doing so unravels details that would otherwise be obscured an ensemble experiment. use optical spectroscopies, SERS, elucidate behavior is attractive alternative traditional approaches scanning microscopy (SECM). While techniques fluorescence or electrogenerated chemiluminescence have used optically monitor events, methodologies, particular, shown great promise exploring nanoscale. ideally suited because Raman-enhancing metallic, substrate duly serves working electrode material. Moreover, ability directly probe without cycling can achieve spatial resolution combination super-resolution microscopies. This Account summarizes latest progress from Van Duyne Willets groups toward understanding nanoelectrochemistry using spectroscopic methodologies. half this highlights three recently few- events: (SMSERS), superlocalization imaging, tip-enhanced (TERS). all studies we discuss model dye systems, experiments described herein push limit, terms both resolution. second discusses current experimental strategies studying techniques, includes relevant electrochemically active molecules, substrates, functionalization methods. In highlight wide variety SERS-active substrates implemented EC-SERS, well need carefully characterize resultant EC-SERS response each new redox-active molecule studied. Finally, conclude our perspective on future directions SERS/TERS, integration SECM TERS theoretical further describe intricacies single-molecule, single-site