3D Photoelectrochemical imaging in porous light-addressable structures

电化学成像技术是研究表面形貌、电荷和催化活性的有力工具，也可用于高分辨率的细胞过程的功能、无标记成像。在能量收集和存储装置等电化学应用中，这些技术可用于研究复杂电极表面上的局部电流，从而有助于开发新的高效电极材料。在生物学中，电化学成像已被用于详细研究分子进出活细胞的运输，细胞形态对刺激和细胞电荷和动作电位的响应变化。然而，目前的电化学成像技术仅限于探测薄膜或材料或活细胞的外表面。最近，在电催化和生物学领域，3D结构都有了很大的发展。复杂的多孔电极结构已被开发用于能量生产和存储设备，如光催化水分解、氧化还原液流电池、燃料电池、电池、超级电容器和电解槽。关于不同形状、大小和连通性的孔隙中电化学过程的局部动力学的详细信息，以及连续运行过程中液体和气体交换的局部效应，可以为新型电极材料的开发提供信息，但目前的电化学技术还无法获得。细胞生物学已经迅速从2D细胞培养转向更复杂的系统，如3D组织培养，在类似于自然组织的环境中研究复杂的生理过程，比如在器官芯片设备中，把电化学成像技术抛在后面追赶。电化学扫描探针技术只能探测到三维结构和细胞的外表面，而光电化学技术则完全局限于平面基底的二维成像。在这个项目中，我们的目标是开发一种光电成像系统，可用于在多孔电极结构中三维绘制电化学过程。这项新技术有望帮助开发用于能量收集和存储设备的新型电极材料，并适用于3D组织培养中的原位3D功能成像，为器官芯片设备的研究领域做出贡献，旨在加快新治疗策略的开发和新药物的发现，同时减少对动物实验的需求。

Electrochemical imaging techniques are powerful tools for the investigation of topography, charge and catalytic activity of surfaces and can also be used for functional, label-free imaging of cellular processes with high resolution. In electrochemical applications such as energy harvesting and storage devices, these techniques can be used to investigate local currents on complex electrode surfaces, thereby aiding the development of new and efficient electrode materials. In biology, electrochemical imaging has been used to carry out detailed investigations into the transport of molecules into or out of living cells, changes in cell morphology in response to stimulation and charges and action potential of cells. However, current electrochemical imaging technologies have been limited to probing thin films or the outer surfaces of materials or living cells. Recently, there has been a strong move towards 3D structures in both electrocatalysis and biology. Complex porous electrode structures have been developed for energy production and storage devices such as photocatalytic water splitting, redox flow batteries, fuel cells, batteries, supercapacitors and electrolysers. Detailed information about the local kinetics of electrochemical processes within pores of different shapes, sizes and interconnectivity and local effects of liquid and gas exchange during continuous operation could inform the development of novel electrode materials, but is not accessible to current electrochemical techniques. Cell biology has been swiftly moving from 2D cell culture to more complicated systems such as 3D tissue culture where complex physiological processes are investigated in an environment that resembles that of natural tissue, such as in organ-on-a chip devices, leaving the electrochemical imaging techniques behind to play catch-up. Only the outer surface of 3D structures and cells has been accessible to electrochemical scanning probe techniques, while photoelectrochemical techniques have been entirely limited to 2D imaging of flat substrates.In this project we aim to develop a photoelectrochemical imaging system that can be used for the mapping of electrochemical processes in three dimensions within porous electrode structures. The new technology is expected to aid the development of novel electrode materials for energy harvesting and storage devices and be suitable for in-situ 3D functional imaging in 3D tissue culture to contribute to the growing research area of organ-on-a chip devices, which aims to speed up the development of new treatment strategies and the discovery of new drugs for a vast range of diseases, while at the same time reducing the need for animal experiments.