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A Solid‐State Protein Junction Serves as a Bias‐Induced Current Switch
Author(s) -
Fereiro Jerry A.,
Kayser Ben,
RomeroMuñiz Carlos,
Vilan Ayelet,
Dolgikh Dmitry A.,
Chertkova Rita V.,
Cuevas Juan Carlos,
Zotti Linda A.,
Pecht Israel,
Sheves Mordechai,
Cahen David
Publication year - 2019
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201906032
Subject(s) - chemistry , electrode , ab initio , monolayer , conductance , atomic orbital , chemical physics , condensed matter physics , materials science , nanotechnology , electron , physics , organic chemistry , quantum mechanics
A sample‐type protein monolayer, that can be a stepping stone to practical devices, can behave as an electrically driven switch. This feat is achieved using a redox protein, cytochrome C (CytC), with its heme shielded from direct contact with the solid‐state electrodes. Ab initio DFT calculations, carried out on the CytC–Au structure, show that the coupling of the heme, the origin of the protein frontier orbitals, to the electrodes is sufficiently weak to prevent Fermi level pinning. Thus, external bias can bring these orbitals in and out of resonance with the electrode. Using a cytochrome C mutant for direct S−Au bonding, approximately 80 % of the Au–CytC–Au junctions show at greater than 0.5 V bias a clear conductance peak, consistent with resonant tunneling. The on–off change persists up to room temperature, demonstrating reversible, bias‐controlled switching of a protein ensemble, which, with its built‐in redundancy, provides a realistic path to protein‐based bioelectronics.