Bioelectrochemistry at the Graphene Edge

长期以来，石墨烯边缘由于其与石墨基面不同的物理和化学性质而受到人们的特别关注。近年来，人们系统地研究了孤立石墨烯边缘电极上的电化学。我们已经证明，我们可以在一维边缘实现电活性物质的高质量传输速率，这使得在GrEdge观察快速电子传递动力学成为可能，没有扩散限制。此外，利用纳米颗粒或有机部分选择性地修饰边缘的可能性，为设计GrEdge开辟了道路，既可以用于涉及反应机制的基础研究，也可以用于传感和电催化。GrEdge可以用作一维介观探针来接近固定实体并在纳米尺度上研究电子转移。在这个项目中，我们朝着这个方向迈出了下一步，并建议将酶专门连接到石墨烯边缘，从而探索固定蛋白质的电子转移的基本方面。除了评估蛋白质选择性附着到边缘的不同方法外，我们还将使用我们最近开发的operando光谱方法来获得附着在碳边缘上的酶的生物电化学机制细节。该项目的预期结果将对酶促生物传感和纳米级电极的生物电催化具有重要意义。

The edge of graphene has long attracted special attention due to its distinct physical and chemical properties in contrast to the graphitic basal plane. Electrochemistry at an isolated graphene edge (GrEdge) electrode has been systematically studied recently. We have shown that we can achieve high mass transport rates for electroactive species at the one-dimensional edge, which has enabled the observation of fast electron transfer kinetics at the GrEdge, free of diffusion limitations. Moreover, the possibility to modify the edge selectively, using nanoparticles or organic moieties, opens avenues for engineering the GrEdge both for fundamental studies involving reaction mechanisms as well as for applications in sensing and electrocatalysis. The GrEdge can be used as a one-dimensional mesoscopic probe to access immobilized entities and investigate electron transfer at the nanoscale. In this project, we take the next step in this direction and propose to wire enzymes specifically to the graphene edge and thereby probe the fundamental aspects of electron transfer with the immobilized proteins. In addition to evaluating different methodologies for selective attachment of the proteins to the edge, we will use operando spectroscopic methods, which we have developed recently, to obtain mechanistic details about the bioelectrochemistry of enzymes attached to the carbon edge. The results expected from this project will have strong implications for enzymatic biosensing and for bioelectrocatalysis at nanoscale electrodes.