Micro-fabricated Helmholtz coil featuring disposable microfluidic sample inserts for applications in nuclear magnetic resonance
Micro-fabricated Helmholtz coil featuring disposable microfluidic sample inserts for applications in nuclear magnetic resonance
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DOI：
10.1088/0960-1317/24/3/034004
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发表时间：
2014-02
影响因子：
2.3
通讯作者：
Nils Spengler;A. Moazenzadeh;R. Meier;V. Badilita;J. Korvink;Ulrike Wallrabe
中科院分区：
文献类型：
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作者：
Nils Spengler;A. Moazenzadeh;R. Meier;V. Badilita;J. Korvink;Ulrike Wallrabe
在这项研究中，我们报告了一种新型、多用途、高分辨率的核磁共振/核磁共振微型检测探针，用于筛选扁平样品。它基于探头中心的Helmholtz线圈对，由两个直径为1.5 mm的引线键合铜线圈组成，从而产生均匀的磁场分布。对于液体和悬浮液，定制制造的一次性样品插入件放置在配对内并自动对齐，防止传感器和样品受到污染。该传感器在500 MHz（11.7 T）光谱仪中成功测试，其中我们实现了1.79 Hz（3.58 ppb）的水模的线宽。章动实验揭示了92%的总体B1场均匀性（在810°/90°的翻转角处的信号强度的比率），导致浓度受限样品的均匀激发。为了证明探测器的成像能力，我们获得了固体和液体样品的图像-一片叶子，直接插入探针和样品插入物，填充有50 μm直径的聚合物珠和去离子水的悬浮液，面内分辨率分别为20 × 20 μ m2和10 × 10 μ m2。
In this study, we report on a novel, multi-use, high-resolution NMR/MRI micro-detection probe for the screening of flat samples. It is based on a Helmholtz coil pair in the centre of the probe, built out of two 1.5 mm diameter wirebonded copper coils, resulting in a homogeneous distribution of the magnetic field. For liquids and suspensions, custom fabricated, disposable sample inserts are placed inside the pair and aligned automatically, preventing the sensor and the samples from contamination. The sensor was successfully tested in a 500 MHz (11.7 T) spectrometer where we achieved a linewidth of 1.79 Hz (3.58 ppb) of a water phantom. Nutation experiments revealed an overall B1-field uniformity of 92% (ratio in signal intensity at flip angles of 810°/90°), leading to a homogeneous excitation of concentration limited samples. To demonstrate the imaging capabilities of the detector, we acquired images of a solid and a liquid sample—of a piece of leaf, directly inserted into the probe and of a sample insert, filled with a suspension of 50 μm diameter polymer beads and deionized water, with in-plane resolutions of 20 × 20 μ m2 and 10 × 10 μ m2, respectively.