Highly Sensitive Planar Anapole Microresonators for Electron Paramagnetic Resonance Spectroscopy of Submicroliter/Submicromolar Samples

用于亚微升/亚微摩尔样品电子顺磁共振波谱分析的高灵敏度平面 Anapole 微谐振器

• 批准号: 9978253
• 负责人: PHYLLIS R ROBINSON
• 金额: $ 21.13万
• 依托单位: UNIVERSITY OF MARYLAND BALTIMORE COUNTY
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-06-08 至 2022-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9978253
• 关键词: Affect; Biological; Biomedical Research; Coupled; Coupling; Crystallization; Detection; Devices; Dimensions; Disease; Drug Design; Drug Targeting; Electron Spin Resonance Spectroscopy; Elements; Film; Frequencies; G-Protein-Coupled Receptors; GTP-Binding Protein alpha Subunits, Gs; Geometry; Goals; Home environment; Laboratory Research; Lead; Magnetism; Membrane Proteins; Methodology; Microfluidic Microchips; Microfluidics; Miniaturization; Modeling; Molecular Conformation; NMR Spectroscopy; Peptides; Performance; Pharmaceutical Preparations; Physiologic pulse; Physiological; Polymers; Proteins; Radiation; Reporting; Sampling; Series; Site; Source; Spin Labels; Structure; Structure-Activity Relationship; System; Techniques; Temperature; Thinness; aqueous; base; biomacromolecule; cold temperature; cryogenics; design; experimental study; improved; innovation; instrument; instrumentation; magnetic field; melanopsin; microwave electromagnetic radiation; nanofabrication; nanolitre; nanolitre scale; nitroxyl; novel; operation; performance tests; protein folding; public health relevance; receptor; simulation; structural biology

Abstract: Electron paramagnetic resonance (EPR) spectroscopy can provide information about the structure and dynamics of biomacromolecules in physiologically relevant conditions. Its inherently high sensitivity is still inadequate for some mass-limited samples -- for example, membrane proteins -- which are notoriously difficult to express, purify, and crystallize. This project aims to decrease the limit of detection for inductive-detection EPR spectroscopy at room temperature, so that low-yield biomacromolecular samples can be studied under physiologically relevant conditions. To achieve this objective, we will use a novel resonator design that bridges the gap between planar microresonators and conventional cavity resonators. Our novel planar inverse anapole microresonator design provides nanoliter active volumes combined with high quality factors, providing a projected improvement of two orders of magnitude in sensitivity at room temperature. Our first aim is to design and fabricate microresonators for operation at 9 GHz and 34 GHz. First, we will carry out finite element simulations of the field distributions and reflection coefficients for resonators coupled to waveguides. Based on these results, we will optimize the device geometry and dimensions to obtain nanoliter magnetic-field hotspots and high quality-factors. We will fabricate these optimized resonators at the NIST Nanofabrication facility. Next, we will characterize the microresonators and integrate them into a commercial 9 GHz and home-built 34 GHz EPR spectrometer. Our second aim is to demonstrate the viability of these resonators for structural biology EPR spectroscopy experiments. To do this, we will first design and fabricate microfluidic devices capable of localizing nanoliter sample volumes in the magnetic hotspot volume of the microresonator. To validate the device performance, we will use a concentration series of spin-labeled peptides. Finally, to demonstrate applicability to a biomacromolecular sample, we will study the Gprotein coupled receptor melanopsin. If successfully implemented, this resonator design will achieve an unprecedented sensitivity for EPR spectroscopy, broadening its applicability to low-yield biomacromolecular samples whose structures are currently poorly understood.

摘要：电子顺磁共振（EPR）波谱可以提供有关 生理相关条件下生物大分子的结构和动力学。其固有的高 对于一些质量有限的样品（例如膜蛋白）来说，灵敏度仍然不够 众所周知，它们很难表达、纯化和结晶。该项目旨在降低 室温下进行感应检测 EPR 光谱检测，因此低产率 生物大分子样品可以在生理相关条件下进行研究。为了实现这一目标 目标，我们将使用一种新颖的谐振器设计来弥补平面微谐振器和 传统的空腔谐振器。我们新颖的平面逆阿极微谐振器设计提供 纳升活性体积与高质量因素相结合，预计可提高两个 室温下的灵敏度提高了几个数量级。我们的首要目标是设计和制造 工作频率为 9 GHz 和 34 GHz 的微谐振器。首先，我们将进行有限元模拟 耦合到波导的谐振器的场分布和反射系数。基于这些 根据结果​​，我们将优化设备的几何形状和尺寸以获得纳升磁场热点 和高品质因数。我们将在 NIST 纳米加工中心制造这些优化的谐振器 设施。接下来，我们将表征微谐振器并将其集成到商用 9 GHz 和 自制 34 GHz EPR 光谱仪。我们的第二个目标是证明这些谐振器的可行性 用于结构生物学 EPR 光谱实验。为此，我们将首先设计和制造 能够将纳升样品体积定位在磁热点体积中的微流体装置 微谐振器。为了验证设备性能，我们将使用一系列浓度的自旋标记 肽。最后，为了证明对生物大分子样品的适用性，我们将研究 G 蛋白 偶联受体黑视蛋白。如果成功实施，该谐振器设计将实现 EPR 光谱前所未有的灵敏度，拓宽了其对低产率的适用性 目前对其结构知之甚少的生物大分子样品。