Department of Materials and Interfaces, Weizmann Institute of Science, Rehovot, Israel.
Departamento de Física Teórica de la Materia Condensada and Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, 28049, Madrid, Spain.
Angew Chem Int Ed Engl. 2019 Aug 19;58(34):11852-11859. doi: 10.1002/anie.201906032. Epub 2019 Jul 25.
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.
一种可以作为实际器件基础的样本型蛋白质单层，能够表现出电驱动开关的特性。这一壮举是通过使用一种氧化还原蛋白——细胞色素 C（CytC）实现的，其卟啉环被屏蔽，以避免与固态电极直接接触。对 CytC-Au 结构进行的从头算 DFT 计算表明，卟啉环与电极的耦合作用非常弱，足以防止费米能级钉扎。因此，外部偏压可以使这些轨道与电极发生共振或失谐。使用一种用于直接 S-Au 键合的细胞色素 C 突变体，在大于 0.5 V 的偏压下，大约 80%的 Au-CytC-Au 结显示出明显的电导峰，这与共振隧穿一致。这种开-关的变化一直持续到室温，证明了蛋白质组合的可逆、偏压控制的开关，其内置的冗余性为基于蛋白质的生物电子学提供了一条现实的途径。
