论文标题
多血红素蛋白质生物电交叉中的三纳米上的非谐振相干电子传输
Off-resonant coherent electron transport over three nanometers in multi-heme protein bioelectronic junctions
论文作者
论文摘要
多血红素细胞色素（MHC）是细菌生物使用的引人入胜的蛋白质，用于在其细胞之间和它们之间穿梭电子。当放置在固态电子连接处时，与其他大小相当大小的氧化还原蛋白相比，几种纳米上的温度无关电流。为了获得对其惊人高电导率的微观见解，我们在此提出了同类的第一个电流计算，该计算是针对两个AU（111）电极之间的MHC，并通过光发射光谱实验互补。我们发现，通过大量蛋白质散发轨道介导的非谐振相干隧道进行传导，这些隧道在血红素和蛋白质残基上强烈取代，实际上将两个电极之间的电流传输。这张图与水溶液中相同蛋白支持的主要电子跳跃机制有很大不同。我们的结果表明，在共鸣状态，例如通过应用栅极电压，使这些蛋白质对于下一代Bionanoelectronic设备非常有趣。
Multi-heme cytochromes (MHC) are fascinating proteins used by bacterial organisms to shuttle electrons within and between their cells. When placed in a solid state electronic junction, they support temperature-independent currents over several nanometers that are three orders of magnitude higher compared to other redox proteins of comparable size. To gain microscopic insight into their astonishingly high conductivities, we present herein the first current-voltage calculations of its kind, for a MHC sandwiched between two Au(111) electrodes, complemented by photo-emission spectroscopy experiments. We find that conduction proceeds via off-resonant coherent tunneling mediated by a large number of protein valence-band orbitals that are strongly delocalized over heme and protein residues, effectively "gating" the current between the two electrodes. This picture is profoundly different from the dominant electron hopping mechanism supported by the same protein in aqueous solution. Our results imply that current output in MHC junctions could be even further increased in the resonant regime, e.g. by application of a gate voltage, making these proteins extremely interesting for next-generation bionanoelectronic devices.
