IDBR: Rapid Scan Electron Paramagnetic Resonance Spectrometer

丹佛大学的桑德拉·伊顿博士获得了一项资助，用于建造一台快速扫描电子顺磁共振(EPR)光谱仪。电子顺磁共振波谱是一种研究含有未配对电子的分子的方法，包括有机自由基和金属离子，它们在健康和疾病的生物系统中发挥着许多关键作用。在这项技术中，磁场被用来区分、定量和测量不同类型的分子和不同环境中未配对电子的变化。自从这项技术被发现以来，在大约60年的时间里，使用这种类型的光谱学已经取得了许多重要的生物学发现。提出了一种新的信号检测方法，改进了对以下类型样本所能获得的信息。在许多重要的生物应用中，信号的浓度变化很快，这使得准确记录信息变得困难。对于其他类型的自由基，传统的信号检测过程会扭曲光谱中的信息。检测方法的改变也将提高生物样品高分辨率成像的灵敏度。此外，这项技术允许测量被未配对的电子吸收的能量释放回环境的速率？这种测量很难用目前的仪器来完成，但它为分子的运动提供了有用的见解。为了使这些开发尽可能广泛地适用，该系统将针对商业光谱仪中最广泛使用的能量范围进行开发。大多数EPR光谱仪通过以每秒几个高斯的速度改变磁场来记录信号，同时监测未配对电子对能量的吸收。将设计和建造一个光谱仪系统来记录信号，同时以每秒数千高斯的速度改变磁场。驱动快速扫描和检测信号的硬件将被设计、建造和系统测试。使用一种非常快速的设备，将来自光谱仪的信号转换成可以平均并存储在计算机中的信息，将允许每秒记录数千次完整的光谱。将使用对信号的计算机处理来提取光谱信息。将开发一个完全集成的硬件和软件系统。在可能的情况下，商业仪器的部件将被纳入该系统，以便用这笔资金开发的设计可以供其他实验室使用。该系统的能力将通过生物样本进行演示。用这笔资金开发的仪器将为这项技术在生物界的应用开辟新的前景。该系统将被很好地记录下来，以优化向其他实验室的转移，并有望刺激商业生产，作为现有光谱仪的附件。所有电路图和机械设计都将公开提供。从本科生到研究生和博士后助理的所有级别的学生都将参与这个连接生物、化学、计算机科学和工程学的跨学科项目。结果将在专业会议上公布，设备将向实验室的参观者展示。

A grant has been awarded to Dr. Sandra Eaton at the University of Denver to build a rapid-scan electron paramagnetic resonance (EPR) spectrometer. EPR spectroscopy is a method to study molecules with unpaired electrons including organic radicals and metal ions that play many crucial roles in healthy and diseased biological systems. In this technique a magnetic field is used to distinguish, quantitate, and measure changes in unpaired electrons in different types of molecules and in different environments. Over the approximately 60 years since the technique was discovered many important biological discoveries have been made using this type of spectroscopy. A new way of detecting the signal is proposed, which will improve the information that can be obtained for the following types of samples. In many important biological applications the concentrations of the signals change quickly, which makes it difficult to record information accurately. For other types of radicals the traditional process of detecting the signals distorts the information in the spectra. The change in the detection method will also improve sensitivity for high resolution imaging of biological samples. Furthermore, this technique permits measurements of the rate at which energy that is absorbed by the unpaired electrons is released back to the surroundings ? this measurement is hard to do with current instrumentation, but provides useful insights into motion of molecules. To make these developments as widely applicable as possible, the system will be developed for the energy range that is most widely used in commercial spectrometers. Most EPR spectrometers record the signal by changing the magnetic field at rates up to a few gauss per second while monitoring the absorption of energy by the unpaired electrons. A spectrometer system will be designed and built to record the signals while changing the magnetic field at rates of many thousands of gauss per second. The hardware to drive the fast scans and to detect the signal will be designed, built, and systematically tested. The use of a very fast device that converts the signal from the spectrometer into information that can be averaged and stored in a computer will permit recording the complete spectrum thousands of times per second. Computer processing of the signal will be used to extract the spectral information. A fully integrated hardware and software system will be developed. Where possible, components from commercially-available instruments will be incorporated into the system so that the design developed with this funding can made available to other laboratories. The capabilities of the system will be demonstrated with biological samples. The instrumentation developed with this funding will open new vistas for application of this technique in the biological community. The system will be well documented to optimize transfer to other laboratories and hopefully stimulate commercial production as an accessory to existing spectrometers. All circuit diagrams and mechanical designs will be openly available. Students at all levels from undergraduate to graduate and postdoctoral associates will be involved in this interdisciplinary projects that bridges biology, chemistry, computer science, and engineering. Results will be presented at professional conferences and the equipment will be demonstrated to visitors to the laboratory.