EPR Imaging

本项目是在分析和表面化学的一般领域和电子顺磁共振（EPR）光谱学的子领域。丹佛大学的Gareth Eaton教授和丹佛科罗拉多大学的Sandra Eaton教授和Martin Maltempo教授正在合作开发EPR成像技术，作为测定各种材料中自由基三维分布的可行工具。该技术还可以确定自由基在空间中每个点的完整超精细光谱，以确定自由基的非均匀分布。这些研究人员目前的努力建立在Gareth和Sandra Eaton在该领域的初始仪器开发工作的基础上，该工作得到了NSF资助CHE-8421281的支持。EPR成像的成功发展将允许在包括生物兴趣在内的广泛材料中对顺磁中心（包括金属和非金属）进行非侵入性的三维表征。与现在发达的核磁共振（NMR）类似物不同，EPR成像具有固有的宽共振，这需要非常强的磁场梯度，以及通常相当稀释的自由基浓度。与此相反的是电子自旋力矩的大小，相应的，信噪比比在核磁共振中遇到的要有利得多。在国家科学基金会授予CHE-8421281的任期内，开发了EPR成像概念验证测试所需的仪器。当前研究的主要重点是开发软件，利用该软件从获取的光谱中重建三维EPR图像并随后呈现；此外，还将确定该技术的应用范围。该研究奖应允许对该分析技术的潜在影响进行批判性评估。

This project is in the general area of analytical and surface chemistry and in the subfield of electron paramagnetic resonance (EPR) spectroscopy. Professor Gareth Eaton of the University of Denver and Professors Sandra Eaton and Martin Maltempo of the University of Colorado at Denver are working collaboratively to develop EPR imaging as a viable tool for the determination of the three-dimensional distribution of radicals in various materials. This technique would also enable the determination of the full hyperfine spectrum of the radical at each point in space, for nonuniform distributions of radicals. The current effort of these investigators builds upon the initial instrumentation development work in this area by Gareth and Sandra Eaton which was supported under NSF grant CHE-8421281. The successful development of EPR imaging would allow the non-invasive, three-dimensional characterization of paramagnetic centers, both metallic and non- metallic, in a broad array of materials including those of biological interest. Unlike its now well-developed nuclear magnetic resonance (NMR) analogue, EPR imaging suffers from inherently broad resonances, which necessitate very strong magnetic field gradients, as well as generally quite dilute concentrations of radicals. Countering this is the magnitude of the electron spin moment and, correspondingly, a signal-to-noise ratio which is significantly more favorable than that encountered in NMR. During the tenure of NSF grant CHE-8421281, the instrumentation necessary for the proof-of-concept testing of EPR imaging was developed. The primary thrust of the current research is the development of the software with which the three-dimensional EPR image is reconstructed from the from the acquired spectra and subsequently presented; also the breadth of application of this technique will be ascertained. This research award should permit a critical assessment of potential impact of this analytical technology.