A Scanning Electrochemical Microscope for the Analysis of Biological Systems

分子通过细胞膜的运输是活细胞为了茁壮成长和繁荣昌盛所需要表现出的最重要的特征之一。为了了解细胞通讯的化学以及与细胞环境和细胞间的分子交换，需要跨学科工具的进步。这项提议正在寻求对扫描电化学显微镜(SECM)的支持，以分析组织细胞和细菌等生物系统。SECM是一种最先进的电分析技术，它使用微米或纳米尺度的电极，并将其横跨表面来分析其电化学活性。该工具由电化学探针扫描仪、集成光学显微镜/CCD摄像机以及荧光模块组成。这种多学科设置使我们能够在电化学测量过程中对样品和详细的电池特性进行光学监控。电化学能够记录毫微微安培范围内的电流，这与氧化还原过程中每秒只转移数千个电子有关，是检测、监测和量化与生物样本相互作用的特定分子的理想工具。由于其高分辨率，SECM能够在单细胞水平和跨种群的水平上研究生物过程的化学。*最初的研究目标是使用微光学环电极，将其实施到SECM中以构成扫描光电化学显微镜(SPECM)，并将其应用于研究辐射诱导的活性氧(ROS)的产生。由于复杂的生物体系中含有大量的电化学活性物质，因此很难对其进行电化学研究。使用SPECM，可以通过其光谱特征来监测氧化还原反应，以区分来自不同物种的电化学贡献。此外，SPECM将允许对单个生物实体进行有针对性的刺激。随着时间的推移，在各种环境条件下，将监测单细胞产生和释放ROS的情况，由此提出的测量方法允许对细胞刺激和分子检测进行前所未有的特异性和局部化。*SECM将向系内、跨系和加拿大的外部用户开放，并将连接分析、物理、药物和生物化学以及生物学方面的各种研究领域。它将进一步为学生和工作人员提供多学科技能和知识基础，使他们能够在未来的学术或工业职业生涯中取得成功。

The transport of molecules across cell membranes is one of the most important features a living cell needs to display in order to thrive and prosper. To understand the chemistry of cell communication and the exchange of molecules with the cell environment and among cells, the advancement of interdisciplinary tools is needed. This proposal is seeking support for a Scanning Electrochemical Microscope (SECM) for the analysis of biological systems, such as tissue cells and bacteria. SECM is a state-of-the-art electroanalytical technique, employing a micro- or nano-scale electrode, which is rastered across a surface to analyze its electrochemical activity. This tool consists of an electrochemical probe scanner, an integrated optical microscope/CCD camera, as well as a fluorescence module. This multidisciplinary setup enables us to optically monitor samples and detailed cell features during electrochemical measurements. Electrochemistry with its ability to record currents in the femto-ampere range, which relates to only a few thousand electrons transferred per second in a redox process, represents an ideal tool to detect, monitor and quantify specific molecules interacting with a biological sample. Due to its high resolution, the SECM is able to investigate the chemistry of biological processes on the single cell level and across populations.***An initial target area of research is the use of micro-optical-ring electrodes, implemented into an SECM to constitute a scanning photoelectrochemical microscope (SPECM), and their application to study the radiation induced production of reactive oxygen species (ROS). Complex biological systems are often difficult to investigate electrochemically, due to the large number of electrochemically active substances. Using SPECM, redox reactions can be monitored by their spectroscopic signature to differentiate between electrochemical contributions from different species. Moreover, the SPECM will allow for targeted stimulation of single biological entities. The generation and release of ROS from single cells will be monitored over time and under various environmental conditions, whereby the proposed measurements allow unprecedented specificity and localization of cellular stimulation and molecule detection. ***The SECM will be open to users within the department, across faculties and to external users in Canada, and will connect a variety of research areas in analytical, physical, medicinal and biochemistry as well as biology. It will further equip students and staff with multidisciplinary skills and a knowledge base to succeed in their future academic or industrial career endeavors.