de Nijs, BartBenz, FelixBarrow, Steven J.Sigle, Daniel O.Chikkaraddy, RohitPalma, AnielloCarnegie, CloudyKamp, MarlousSundararaman, RavishankarNarang, PrinehaScherman, Oren A.Baumberg, Jeremy J.2018-01-182017de Nijs, B., F. Benz, S. J. Barrow, D. O. Sigle, R. Chikkaraddy, A. Palma, C. Carnegie, et al. 2017. “Plasmonic tunnel junctions for single-molecule redox chemistry.” Nature Communications 8 (1): 994. doi:10.1038/s41467-017-00819-7. http://dx.doi.org/10.1038/s41467-017-00819-7.http://nrs.harvard.edu/urn-3:HUL.InstRepos:34652069Nanoparticles attached just above a flat metallic surface can trap optical fields in the nanoscale gap. This enables local spectroscopy of a few molecules within each coupled plasmonic hotspot, with near thousand-fold enhancement of the incident fields. As a result of non-radiative relaxation pathways, the plasmons in such sub-nanometre cavities generate hot charge carriers, which can catalyse chemical reactions or induce redox processes in molecules located within the plasmonic hotspots. Here, surface-enhanced Raman spectroscopy allows us to track these hot-electron-induced chemical reduction processes in a series of different aromatic molecules. We demonstrate that by increasing the tunnelling barrier height and the dephasing strength, a transition from coherent to hopping electron transport occurs, enabling observation of redox processes in real time at the single-molecule level.en-USJournal Article2018-01-1810.1038/s41467-017-00819-7