Electron transport through self-assembled monolayers of tripeptides
| Autor: | Mervinetsky, E., Alshanski, I., Lenfant, S., Guerin, D., Sandonas, L. Medrano, Dianat, A., Gutierrez, R., Cuniberti, G., Hurevich, M., Yitzchaik, S., Vuillaume, D. |
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| Rok vydání: | 2019 |
| Předmět: | |
| Zdroj: | J. Phys. Chem. C .123 (14), 9600-9608 (2019) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1021/acs.jpcc.9b01082 |
| Popis: | We report how the electron transport through a solid-state metal/Gly-Gly-His tripeptide (GGH) monolayer/metal junction and the metal/GGH work function are modified by the GGH complexation with Cu2+ ions. Conducting AFM is used to measure the current-voltage histograms. The work function is characterized by combining macroscopic Kelvin probe and Kelvin probe force microscopy at the nanoscale. We observe that the Cu2+ ions complexation with the GGH monolayer is highly dependent on the molecular surface density and results in opposite trends. In the case of a high density monolayer the conformational changes are hindered by the proximity of the neighboring peptides, hence forming an insulating layer in response to copper-complexation. Whereas the slightly lower density monolayers allow for the conformational change to a looped peptide wrapping the Cu-ion, which results in a more conductive monolayer. Copper-ion complexation to the high- and low-density monolayers systematically induces an increase of the work functions. Copper-ion complexation to the low-density monolayer induces an increase of electron transport efficiency, while the copper-ion complexation to the high-density monolayer results in a slight decrease of electron transport. Both of the observed trends are in agreement with first-principle calculations. Complexed copper to low density GGH-monolayer induces a new gap state slightly above the Au Fermi energy that is absent in the high density monolayer. Comment: Full paper with supporting information |
| Databáze: | arXiv |
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