Key Laboratory of Organic Optoelectronics and Molecular Engineering and Laboratory of Flexible Electronics Technology, Department of Chemistry, Tsinghua University, 100084, Beijing, China.
Adv Mater. 2023 Jun;35(26):e2300663. doi: 10.1002/adma.202300663. Epub 2023 May 13.
The study of charge transport through proteins is essential for understanding complicated electrochemical processes in biological activities while the reasons for the coexistence of tunneling and hopping phenomena in protein junctions still remain unclear. In this work, a flexible and conductive ionogel electrode is synthesized and is used as a top contact to form highly reproducible protein junctions. The junctions of proteins, including human serum albumin, cytochrome C and hemoglobin, show temperature-independent electron tunneling characteristics when the junctions are in solid states while with a different mechanism of temperature-dependent electron hopping when junctions are hydrated under physiologically relevant conditions. It is demonstrated that the solvent reorganization energy plays an important role in the electron-hopping process and experimentally shown that it requires ≈100 meV for electron hopping through one heme group inside a hydrated protein molecule connected between two electrodes.
研究电荷通过蛋白质的输运对于理解生物活性中复杂的电化学过程至关重要，而蛋白质结中隧穿和跳跃现象共存的原因仍不清楚。在这项工作中，合成了一种灵活的导电离子凝胶电极，并用作顶部接触，以形成高度重现的蛋白质结。当蛋白质结（包括人血清白蛋白、细胞色素 C 和血红蛋白）处于固态时，它们表现出与温度无关的电子隧穿特性，而当在生理相关条件下水合时，它们表现出与温度相关的电子跳跃不同的机制。结果表明，溶剂重组能在电子跳跃过程中起着重要作用，实验表明，在两个电极之间连接的水合蛋白质分子中，通过一个血红素基团进行电子跳跃需要约 100 meV 的能量。
