Scanning Photoelectrochemical Microscopy and its Application to Biological Systems

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。特殊的微纳探针，如微光环(MOR)电极，由电极套内的光纤组成，允许局部照射和同时测量样品的电化学响应。这些探针已经显示出它们在非生物应用中的有效性，但还没有人利用MOR电极在微米和纳米尺度上应用于监测生物系统中辐射敏感的氧化还原过程。所描述的计划位于电化学、分析化学和生物学的交叉点，旨在更好地了解在各种环境条件下生物细胞中产生活性氧物种(ROS)和活性氮物种(RNS)的基本机制。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，对单一生物实体的有针对性的刺激是具有挑战性的。单个生物细胞通过MOR电极的特定局部照射，同时测量它们的电化学响应，将为深入了解辐射诱导ROS/RNS的产生提供基础。本研究旨在更好地了解细胞在存在抗氧化剂等刺激剂和抑制剂的情况下应对和反应机制的时间反应和效率。从该项目毕业的学生将具备多学科技能和知识基础，以便在未来的学术或工业职业生涯中取得成功。

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. Specialized micro- and nano-probes, such as micro-optical-ring (MOR) electrodes, consisting of optical fibers within an electrode sheath, allow localized irradiation and concurrent measurement of the electrochemical response of a sample. These probes have shown their usefulness in non-biological applications, but the opportunity no one has taken is the application of MOR electrodes to monitor radiation sensitive redox processes in biological systems on the micro- and nanoscale. The described program lies at the intersection of electrochemistry, analytical chemistry and biology and aims to better understand fundamental mechanisms related to the generation of reactive oxygen species (ROS) and reactive nitrogen species (RNS) in biological cells under various environmental conditions. 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, targeted stimulation of single biological entities is challenging to achieve. The specific local illumination of single biological cells through MOR electrodes while measuring their electrochemical response will provide fundamental insight into the radiation induced production of ROS/RNS. This research aims to better understand the time response and efficiency of cellular coping and reaction mechanisms in the presence of stimulants and inhibitors, such as antioxidants. Students emerging from this program will be equipped with multidisciplinary skills and a knowledge base to succeed in their future academic or industrial career endeavors.