Abstract
The finding that electronic conductance across ultrathin protein films between metallic electrodes remains nearly constant from room temperature to just a few degrees Kelvin has posed a challenge. We show that a model based on a generalized Landauer formula explains the nearly constant conductance and predicts an Arrhenius-like dependence for low temperatures. A critical aspect of the model is that the relevant activation energy for conductance is either the difference between the HOMO and HOMO-1 or the LUMO+1 and LUMO energies instead of the HOMO-LUMO gap of the proteins. Analysis of experimental data confirms the Arrhenius-like law and allows us to extract the activation energies. We then calculate the energy differences with advanced DFT methods for proteins used in the experiments. Our main result is that the experimental and theoretical activation energies for these three different proteins and three differently prepared solid-state junctions match nearly perfectly, implying the mechanism’s validity.
Original language | English |
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Pages (from-to) | 1728-1734 |
Number of pages | 7 |
Journal | Journal of Physical Chemistry B |
Volume | 127 |
Issue number | 8 |
DOIs | |
State | Published - 2 Mar 2023 |
Externally published | Yes |
Bibliographical note
Publisher Copyright:© 2023 American Chemical Society.
Funding
The scientific work and results published in this paper were reached with the sponsorship of the Gedeon Richter Talentum Foundation in the framework of the Gedeon Richter Excellence Ph.D. Scholarship of Gedeon Richter. This research was supported by the Ministry of Culture and Innovation and the National Research, Development and Innovation Office within the Quantum Information National Laboratory of Hungary (Grant No. 2022-2.1.1-NL-2022-00004). L.A.Z. thanks the financial support from MCIN/AEI/10.13039/501100011033 (grant PID2021-125604NB-I00) and from the Universidad Autónoma de Madrid/Comunidad de Madrid (grant No. SI3/PJI/2021-00191). C.R.-M. acknowledges funding from the Plan Andaluz de Investigación, Desarrollo e Innovación (PAIDI2020) of Junta de Andalucía. At the Weizmann Inst., this work was supported by a grant from the Israel Science Foundation, the DFG, and, for J.A.F., the Azrieli foundation. J.A.F. acknowledges the Science and Engineering Board (SERB) of the Department of Science and Technology (CRG/2022/000584), Government of India, for financial support. M.S. holds the Katzir-Makineni Chair in Chemistry. D.C., M.S., and J.A.F. thank D A Dolikh and R V Cherkova, Shemyakin-Ovchinnikov Inst. of Bioorg. Chem., Russ. Acad. Sci, Moscow, for the Cyt C (E104) mutant (see ref (19)). The scientific work and results published in this paper were reached with the sponsorship of the Gedeon Richter Talentum Foundation in the framework of the Gedeon Richter Excellence Ph.D. Scholarship of Gedeon Richter. This research was supported by the Ministry of Culture and Innovation and the National Research, Development and Innovation Office within the Quantum Information National Laboratory of Hungary (Grant No. 2022-2.1.1-NL-2022-00004). L.A.Z. thanks the financial support from MCIN/AEI/10.13039/501100011033 (grant PID2021-125604NB-I00) and from the Universidad Autónoma de Madrid/Comunidad de Madrid (grant No. SI3/PJI/2021-00191). C.R.-M. acknowledges funding from the Plan Andaluz de Investigación, Desarrollo e Innovación (PAIDI2020) of Junta de Andalucía. At the Weizmann Inst., this work was supported by a grant from the Israel Science Foundation, the DFG, and, for J.A.F., the Azrieli foundation. J.A.F. acknowledges the Science and Engineering Board (SERB) of the Department of Science and Technology (CRG/2022/000584), Government of India, for financial support. M.S. holds the Katzir-Makineni Chair in Chemistry. D.C., M.S., and J.A.F. thank D A Dolikh and R V Cherkova, Shemyakin-Ovchinnikov Inst. of Bioorg. Chem., Russ. Acad. Sci, Moscow, for the Cyt C (E104) mutant (see ref ).
Funders | Funder number |
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D A Dolikh and R V Cherkova | |
Ministry of Culture and Innovation | |
Plan Andaluz de Investigación, Desarrollo e Innovación | PAIDI2020 |
Quantum Information National Laboratory of Hungary | MCIN/AEI/10.13039/501100011033, PID2021-125604NB-I00, 2022-2.1.1-NL-2022-00004 |
Science and Engineering Board | |
Shemyakin-Ovchinnikov Inst | E104 |
Universidad Autónoma de Madrid/Comunidad de Madrid | SI3/PJI/2021-00191 |
Department of Science and Technology, Ministry of Science and Technology, India | CRG/2022/000584 |
Deutsche Forschungsgemeinschaft | |
Israel Science Foundation | |
Azrieli Foundation | |
Junta de Andalucía | |
Nemzeti Kutatási Fejlesztési és Innovációs Hivatal | |
Richter Gedeon Talentum Alapítvány |