A Solid‐State Protein Junction Serves as a Bias‐Induced Current Switch. Issue 34 (25th July 2019)

• Record Type: Journal Article
• Authors: Fereiro, Jerry A.; Kayser, Ben; Romero‐Muñiz, Carlos; Vilan, Ayelet; Dolgikh, Dmitry A.; Chertkova, Rita V.; Cuevas, Juan Carlos; Zotti, Linda A.; Pecht, Israel; Sheves, Mordechai; Cahen, David
• Is Part Of: Angewandte Chemie international edition. Volume 58:Issue 34(2019)
• Page Start: 11852
• Page End: 11859
• Publication Date: 2019-07-25
• Subjects: bioelectronic junction -- electron transfer -- on–off switching -- resonant tunneling; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201906032
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: 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. Abstract : Down to the wire : A cytochrome C monolayer, attached to a Au layer using S−Au bonding, and coated with a Au nanowire, can behave as an electrically driven switch. The charge‐transport mechanism of cytochrome C can be switched between on‐and off‐resonant tunneling by varying the applied voltage bias, even at room temperature. This is an important step towards protein‐based electronics.