Scanning Photoelectrochemical Microscopy and its Application to Biological Systems

电化学能够记录飞安培范围内的电流，在氧化还原过程中每秒只转移几千个电子，是检测、监测和量化与生物样品相互作用的特定分子的理想工具。特殊的微探针和纳米探针，如微光环（MOR）电极，由电极鞘内的光纤组成，允许局部照射和同时测量样品的电化学响应。这些探针已经在非生物应用中显示出了它们的实用性，但是还没有人抓住机会在微纳米尺度上应用MOR电极来监测生物系统中辐射敏感的氧化还原过程。所描述的程序位于电化学，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活性氧（ROS）和活性氮（RNS）产生的基本机制。由于存在大量的电化学活性物质，复杂的生物系统往往难以进行电化学研究。利用SPECM，氧化还原反应可以通过其光谱特征来监测，以区分不同物质的电化学贡献。此外，单一生物实体的定向刺激很难实现。通过MOR电极对单个生物细胞进行特定的局部照明，同时测量其电化学响应，将为辐射诱导ROS/RNS的产生提供基本的见解。本研究旨在更好地了解在兴奋剂和抑制剂（如抗氧化剂）存在下细胞应对和反应机制的时间反应和效率。从该课程中脱颖而出的学生将具备多学科技能和知识基础，以在他们未来的学术或工业生涯中取得成功。

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.