Liquid state Dynamic Nuclear Polarization probe with Fabry-Perot resonator at 9.2 T
Liquid state Dynamic Nuclear Polarization probe with Fabry-Perot resonator at 9.2 T
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DOI：
10.1016/j.jmr.2012.01.014
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发表时间：
2012-04-01
影响因子：
2.2
通讯作者：
Prisner, Thomas
中科院分区：
文献类型：
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作者：
Denysenkov, Vasyl;Prisner, Thomas
最近在高磁场下液态 DNP 方面取得的成就显示出对水溶液的显着增强，引发了人们对该方法在生物分子研究中的可能应用的浓厚兴趣。然而，由于高微波损失导致样品过度加热，在环境温度下对生物分子进行原位 DNP 是一项具有挑战性的任务。为了避免这种加热，必须大幅减少样品体积，以使其远离微波场的电成分。螺旋双共振结构首次演示了 Overhauser DNP 在高磁场 (9.2 T) 下对水溶液的适用性，将样品尺寸限制在 2 nl 的极小体积。再加上光谱分辨率较差，这导致整体信号幅度较小，阻碍了对生物分子的观察。在这里，我们提出了一种新型的液态 DNP 双共振结构，它由用于微波激发的法布里-珀罗谐振器和用于核磁共振检测的带状线谐振器组成。相对于螺旋探针，这种新的双共振结构 (260 GHz/400 MHz) 使水样体积 (80 nl) 增加了 30 倍，并表现出改进的 NMR 灵敏度和线宽。 (C) 2012 Elsevier Inc. 保留所有权利。
Recent achievements in liquid state DNP at high magnetic fields showing significant enhancements on aqueous solutions have initiated strong interest in possible applications of this method to biomolecular research. However, in situ DNP of biomolecules at ambient temperatures is a challenging task due to high microwave losses leading to excessive sample heating. To avoid such heating the sample volume has to be reduced strongly to keep it away from the electric component of the microwave field. A helical double resonance structure, used for the first demonstrations of the applicability of Overhauser DNP to aqueous solutions at high magnetic fields (9.2 T), restricted the sample size to a very small volume of 2 nl. Together with a poor spectral resolution this resulted in small overall signal amplitude, hampering observations of biomolecules. Here we present a new type of the double resonance structure for liquid-state DNP which consists of a Fabry-Perot resonator for the microwave excitation and a stripline resonator for the NMR detection. This new double resonance structure (260 GHz/400 MHz) offers a 30-fold increase in aqueous sample volume (80 nl) with respect to the helical probe and exhibits improved NMR sensitivity and linewidth. (C) 2012 Elsevier Inc. All rights reserved.