Groningen University, University Medical Center Groningen, Antonius Deusinglaan 1, 9713 AW Groningen, The Netherlands.
Institute of Physics, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland.
ACS Sens. 2023 Apr 28;8(4):1667-1675. doi: 10.1021/acssensors.2c02809. Epub 2023 Apr 12.
We present an alternative to conventional Electron Paramagnetic Resonance (EPR) spectroscopy equipment. Avoiding the use of bulky magnets and magnetron equipment, we use the photoluminescence of an ensemble of Nitrogen-Vacancy centers at the surface of a diamond. Monitoring their relaxation time (or T1), we detected their cross-relaxation with a compound of interest. In addition, the EPR spectra are encoded through a localized magnetic field gradient. While recording previous data took 12 min per data point with individual NV centers, we were able to reconstruct a full spectrum at once in 3 s, over a range from 3 to 11 G. In terms of sensitivity, only 0.5 μL of a 1 μM hexaaquacopper(II) ion solution was necessary.
我们提出了一种替代传统电子顺磁共振（EPR）光谱仪的方法。我们避免使用庞大的磁铁和磁控管设备，而是利用钻石表面氮空位中心的集体光致发光。通过监测它们的弛豫时间（或 T1），我们检测到它们与感兴趣的化合物的交叉弛豫。此外，EPR 光谱通过局部磁场梯度进行编码。在使用单个 NV 中心记录以前的数据时，每个数据点需要 12 分钟，而我们能够在 3 秒内一次重建整个光谱，范围从 3 到 11 G。在灵敏度方面，只需要 0.5 μL 浓度为 1 μM 的六水合铜（II）离子溶液。
