论文标题
使用纳米级钻石磁力测定法对脂质双层的无标签相变。
Label-free phase change detection of lipid bilayers using nanoscale diamond magnetometry
论文作者
论文摘要
钻石中的NV中心是一个量子传感器，具有高度敏感的NANOSCALE分析NMR光谱和温度法，具有出色的质量。在这项研究中，我们研究了脂质双层的纳米级变化检测，利用了从小体积〜（6 nm）$^{3} $的集合平均核自旋检测，这是由NV中心深度确定的。纳米级NMR信号的分析确认脂质双层的厚度为6.2 nm $ \ pm $ 3.4 nm，质子密度为65质子/nm $^{3} $验证在钻石样品顶部的脂质双层的形成。来自纳米级体积的相关光谱揭示了在3.06 MHz处的量子振荡，对应于71.8 MT的施加磁场下质子的Larmor频率。将相关光谱的结果与由蒙特卡洛模拟构成的2D分子扩散模型以及分子动力学模拟的结果进行了比较。扩散常数从1.5 $ \ pm $ 0.25 nm $^{2} $/$/$/$/$/$ $ s改为3.0 $ \ pm $ \ pm $ 0.5 nm $^{2} $/$/$/$ $ $当温度从26.5 $^\ circe circe $ c to 36.0 $^\ circird $ c中变化时。我们的结果表明，在使用纳米级钻石磁力测定法的无标签测量中，可以同时观察转化扩散和温度的变化。我们的方法为细胞膜的无标签成像铺平了道路，以理解其相位组成和动力学。
The NV center in a diamond is a quantum sensor with exceptional quality for highly sensitive nanoscale analysis of NMR spectra and thermometry. In this study, we investigate nanoscale phase change detection of lipid bilayers utilizing ensemble-averaged nuclear spin detection from small volume ~ (6 nm)$^{3}$, which was determined by the depth of the NV center. Analysis of nanoscale NMR signal confirm thickness of lipid bilayer to be 6.2 nm $\pm$ 3.4 nm with proton density of 65 proton/nm$^{3}$ verifying formation of lipid bilayer on top of diamond sample. Correlation spectroscopy from nanoscale volume reveals quantum oscillation at 3.06 MHz corresponding to the Larmor frequency of proton at an applied magnetic field of 71.8 mT. The result of the correlation spectroscopy was compared with the 2D molecular diffusion model constructed by Monte Carlo simulation combined with results from molecular dynamics simulation. There is a change in diffusion constant from 1.5 $\pm$ 0.25 nm$^{2}$/$μ$s to 3.0 $\pm$ 0.5 nm$^{2}$/$μ$s when the temperature changes from 26.5 $^\circ$C to 36.0 $^\circ$C. Our results demonstrate that simultaneous observation of changes in translational diffusion and temperature is possible in label-free measurements using nanoscale diamond magnetometry. Our method paves the way for label-free imaging of cell membranes for understanding its phase composition and dynamics.
