Assembled amyloid beta (Aβ) peptides have been considered pathological assemblies involved in human brain diseases, and the electron transfer or electron transport characteristics of Aβ are important for the formation of structured assemblies. Here, we report the electrical characteristics of surface-assembled Aβ peptides similar to those observed in Alzheimer’s patients. These characteristics correlate to their electron transfer characteristics. Electrical current–voltage plots of Aβ vertical junction devices show the Aβ sequence dependence of the current densities at both Aβ monomers (mono-Aβs) and Aβ oligomers (oli-Aβs), while Aβ sequence dependence is not clearly observed in the electrical characteristics of Aβ planar field effect transistors (FETs). In particular, surface oligomerization of Aβ peptides drastically decreases the activity of electron transfer, which presents a change in the electron transport pathway in the Aβ vertical junctions. Electron transport at oli-Aβ junctions is symmetric (tunneling/tunneling) due to the weak and voltage-independent coupling of the less redox-reactive oli-Aβ to the contacts, while that at mono-Aβ junctions is asymmetric (hopping/tunneling) due to redox levels of mono-Aβ voltage-dependently coupled with contact electrodes. Consequently, through vertical junctions, the sequence- and conformation-dependent electrical characteristics of Aβs can reveal their electron transfer activities.

组装的 β 淀粉样蛋白 (Aβ) 肽被认为是参与人脑疾病的病理性组装，Aβ 的电子转移或电子传输特性对于结构化组装的形成很重要。在这里，我们报告了表面组装的 Aβ 肽的电特性，类似于在阿尔茨海默病患者中观察到的那些。这些特性与其电子转移特性相关。Aβ 垂直结器件的电流-电压图显示了 Aβ 单体（单-Aβs）和 Aβ 寡聚体（oli-Aβs)，而在 Aβ 平面场效应晶体管 (FET) 的电气特性中没有清楚地观察到 Aβ 序列依赖性。特别是，Aβ 肽的表面寡聚化显着降低了电子转移的活性，这表明 Aβ 垂直连接中的电子传递途径发生了变化。在电子传输oli- Aβ结是对称的（隧穿/隧道），由于氧化还原较少反应性的弱和电压无关的耦合OLI -Aβ到触点，而在单-Aβ结是不对称的（跳跃/隧穿）由于单声道的氧化还原水平-Aβ 电压依赖性地与接触电极耦合。因此，通过垂直连接，Aβ 依赖于序列和构象的电特性可以揭示它们的电子转移活动。