Lv Yujia, Liang Dawei, Lu Shanfu, Aurbach Doron, Xiang Yan
Department of Space and Environment, Beihang University, Beijing, 100191, PR China; Beijing Key Laboratory of Bio-inspired Energy Materials and Devices, Beihang University, Beijing, 100191, PR China.
Department of Space and Environment, Beihang University, Beijing, 100191, PR China.
Biosens Bioelectron. 2021 Feb 1;173:112811. doi: 10.1016/j.bios.2020.112811. Epub 2020 Nov 9.
Hampered by the absence of evidence and theoretical model of biological semiconductors, the unidirectional electron transport via the p-n junction between functional proteins and abiotic materials remains a challenge for bioelectronics. Bacteriorhodopsin (bR), a representative transmembrane protein, has demonstrated exceptional optoelectronic effects in bR/semiconductor hybrid materials and offers a possible pathway for addressing this challenge. In the present work, for the first time, bR is proved to be an n-type semiconductor with an indirect electron transition. Through the photo-electrochemical method used for studying the p-n junction effect in the bR and p-type semiconductor combined electrodes, we reached several important conclusions: The self-corrosion of bR integrated CuO electrodes is delayed for about 36 times; The photocurrent of bR integrated CuSCN electrodes is enhanced by about 400%, which is attributed to the directional migration of electrons via the p-n junction. Furthermore, the ultrafast kinetics we have explored, shows that the injection of electrons shortens the lifetime of the intermediate state O from 37.3 μs to 20.1 μs, what means that the protons transport rate accompanying the bR photocycle process is accelerated. Therefore, we believe that the concept of the bio-p-n junction and the mechanism of electron coupled proton transport, which are discussed herein, will promote useful research on bioelectronic applications for bR and its homologs.
由于缺乏生物半导体的证据和理论模型，通过功能蛋白与非生物材料之间的 p-n 结进行单向电子传输仍然是生物电子学面临的一项挑战。细菌视紫红质（bR）是一种代表性的跨膜蛋白，已在 bR/半导体混合材料中展现出卓越的光电效应，并为应对这一挑战提供了一条可能的途径。在本工作中，首次证明 bR 是一种具有间接电子跃迁的 n 型半导体。通过用于研究 bR 与 p 型半导体复合电极中 p-n 结效应的光电化学方法，我们得出了几个重要结论：bR 集成 CuO 电极的自腐蚀延迟了约 36 倍；bR 集成 CuSCN 电极的光电流增强了约 400%，这归因于电子通过 p-n 结的定向迁移。此外，我们所探索的超快动力学表明，电子注入将中间态 O 的寿命从 37.3 μs 缩短至 20.1 μs，这意味着伴随 bR 光循环过程的质子传输速率加快。因此，我们相信本文所讨论的生物 p-n 结概念以及电子耦合质子传输机制，将推动针对 bR 及其同源物的生物电子应用的有益研究。
