High-resolution magnetic resonance spectroscopy using a solid-state spin sensor
High-resolution magnetic resonance spectroscopy using a solid-state spin sensor
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DOI：
10.1038/nature25781
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发表时间：
2018-03-15
期刊：
影响因子：
64.8
通讯作者：
Walsworth, Ronald L.
中科院分区：
文献类型：
--
作者：
Glenn, David R.;Bucher, Dominik B.;Walsworth, Ronald L.
由固态电子自旋组成的量子系统可以成为核磁共振（NMR）信号的敏感探测器，特别是来自非常小的样本。例如，金刚石中的氮空位中心已被用于记录纳米级样品的核磁共振信号（1-3），其灵敏度足以检测单个蛋白质产生的磁场(4)。然而，据报道，利用氮空位中心对分子进行NMR的最佳光谱分辨率约为100赫兹(5)。这不足以解决分子结构的关键光谱标识符，这些标识符对于核磁共振在化学、结构生物学和材料研究中的应用至关重要，例如标量耦合（需要小于10赫兹的分辨率）和小的化学位移（需要大约百万分之一核拉莫尔频率的分辨率）。传统的电感检测核磁共振可以提供必要的高光谱分辨率，但其有限的灵敏度通常需要毫米级的样品，这就排除了涉及较小样品的应用，例如皮升体积的化学分析或相关光学和核磁共振显微镜。在这里，我们展示了一种测量技术，该技术使用由氮空位中心集合组成的固态自旋传感器（磁力计）与窄带同步读出协议（7-9）相结合，以获得约1赫兹的核磁共振光谱分辨率。我们使用这种技术在大约10皮升的微米尺度样品体积中观察核磁共振标量耦合。我们还使用氮空位中心系综将核磁共振应用于热极化核自旋，并从小分子中解析化学位移谱。我们的技术使分析核磁共振光谱在单细胞的规模。
Quantum systems that consist of solid-state electronic spins can be sensitive detectors of nuclear magnetic resonance (NMR) signals, particularly from very small samples. For example, nitrogen-vacancy centres in diamond have been used to record NMR signals from nanometre-scale samples(1-3), with sensitivity sufficient to detect the magnetic field produced by a single protein(4). However, the best reported spectral resolution for NMR of molecules using nitrogen-vacancy centres is about 100 hertz(5). This is insufficient to resolve the key spectral identifiers of molecular structure that are critical to NMR applications in chemistry, structural biology and materials research, such as scalar couplings (which require a resolution of less than ten hertz(6)) and small chemical shifts (which require a resolution of around one part per million of the nuclear Larmor frequency). Conventional, inductively detected NMR can provide the necessary high spectral resolution, but its limited sensitivity typically requires millimetre-scale samples, precluding applications that involve smaller samples, such as picolitre-volume chemical analysis or correlated optical and NMR microscopy. Here we demonstrate a measurement technique that uses a solid-state spin sensor (a magnetometer) consisting of an ensemble of nitrogen-vacancy centres in combination with a narrowband synchronized readout protocol(7-9) to obtain NMR spectral resolution of about one hertz. We use this technique to observe NMR scalar couplings in a micrometre-scale sample volume of approximately ten picolitres. We also use the ensemble of nitrogen-vacancy centres to apply NMR to thermally polarized nuclear spins and resolve chemicalshift spectra from small molecules. Our technique enables analytical NMR spectroscopy at the scale of single cells.