Spin-labeling Electron Paramagnetic Resonance Methods for Measurements at Nanoscale Interfaces

用于纳米级界面测量的自旋标记电子顺磁共振方法

• 批准号: 2305172
• 负责人: Tatyana Smirnova
• 金额: $ 43.5万
• 依托单位: North Carolina State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-08-01 至 2026-07-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2305172&HistoricalAwards=false
• 关键词: Spin; labeling; Electron; Paramagnetic; Resonance

With support from the Chemical Measurement and Imaging Program in the Division of Chemistry, Tatyana Smirnova and her group at North Carolina State University are working on developing a novel measurement methodology to assess properties of nanoparticles at interfaces. As particles become smaller and approach the nanoscale – typically 1 to 100 nm in diameter (thousands of times smaller than the diameter of a human hair) - interfacial properties become the dominant factors in interactions of the particles with their surroundings. This project aims to address the need for measurements at nanostructured interfaces by positioning molecular probes at the nanoparticle surface with atomic-scale precision and reading the interfacial properties spectroscopically. Once developed, the new measurement method has the potential to yield much needed data that will aid in the design of novel materials as well as improve manufacturing processes. Direct participation of graduate and undergraduate students will provide for specialized training in materials, physical, and analytical chemistry. Selected elements of the research plan are directly integrated in undergraduate classroom laboratory activities, bringing a discovery-based approach to undergraduate education.The proposed approach to develop a new measurement capability is based on a series of spectroscopically active probes, which will be covalently attached to nanostructured surfaces via common surface groups to assess local dynamics, proton concentration and electrostatic and dielectric properties at interfaces. The approach utilizes electron paramagnetic resonance (EPR) and is expected to provide unique capability to report on highly local, site-specific heterogeneous properties of nanoscale interfaces. The position of the probe with respect to the interface will be determined with atomic-scale accuracy from measurements of dipolar interactions between the electronic spin of the probe and the surface magnetic nuclei by pulsed EPR. The validity of the measurement approach will be investigated over a wide range of environmental conditions to demonstrate a broad applicability of the method to nanosystems of interest in materials science, chemistry, and biology.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

在化学系化学测量和成像项目的支持下，塔蒂亚娜·斯米尔诺娃（Tatyana Smirnova）和她在北卡罗来纳州立大学的团队正在开发一种新颖的测量方法来评估纳米粒子在界面处的特性，因为粒子变得更小并接近纳米尺度。通常为 1 至 100 nm（比人类头发直径小数千倍）——界面特性成为颗粒直径与其周围环境相互作用的主导因素。通过以原子级精度将分子探针定位在纳米颗粒表面并通过光谱读取界面特性来测量纳米结构界面，一旦开发出来，新的测量方法就有可能产生急需的数据，这也将有助于新型材料的设计。研究生和本科生的直接参与将提供材料、物理和分析化学方面的专业培训，并将其直接纳入本科生课堂实验室活动，从而为本科生教育带来基于发现的方法。 .建议的方法开发一种新的测量能力是基于一系列光谱活性探针，这些探针将通过共同的表面基团共价连接到纳米结构表面，以评估界面处的局部动力学、质子浓度以及静电和介电特性。 EPR），预计将提供独特的能力来报告纳米级界面的高度局部的、特定位置的异质特性。探针相对于界面的位置将通过测量来以原子级精度确定。通过脉冲 EPR 测量探针的电子自旋与表面核之间的偶极相互作用。将在广泛的环境条件下研究测量方法的有效性，以证明该方法对材料科学感兴趣的纳米系统的广泛适用性。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。