A Scanning Electrochemical Microscope for the Analysis of Biological Systems

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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.