Toward Nanomolar Detection by NMR Through SABRE Hyperpolarization
Toward Nanomolar Detection by NMR Through SABRE Hyperpolarization
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DOI：
10.1021/ja412994k
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发表时间：
2014-02-19
影响因子：
15
通讯作者：
Tessari, Marco
中科院分区：
文献类型：
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作者：
Eshuis, Nan;Hermkens, Niels;Tessari, Marco
SABRE 是一种核自旋超极化技术，基于底物分子和仲氢 (p-H-2) 与金属络合物的可逆缔合。在这种复合物的寿命期间（通常为几分之一秒），p-H-2 的自旋顺序通过瞬态标量耦合网络转移到底物分子的核自旋，从而产生强烈增强的 NMR 信号。该技术通常在相对较高的浓度（mM）下应用，相对于金属络合物大大过量的底物。低于化学计量的底物配体稀释会导致信号增强逐渐减弱，这妨碍了 SABRE 直接应用于低浓度 (μM) 溶液的 NMR 分析。在这里，我们表明，通过向溶液中添加合适的配位体，可以恢复 SABER 在低底物浓度下的效率。所提出的方法允许在单次扫描中进行 1 μM 以下的 NMR 检测。
SABRE is a nuclear spin hyperpolarization technique based on the reversible association of a substrate molecule and para-hydrogen (p-H-2) to a metal complex. During the lifetime of such a complex, generally fractions of a second, the spin order of p-H-2 is transferred to the nuclear spins of the substrate molecule via a transient scalar coupling network, resulting in strongly enhanced NMR signals. This technique is generally applied at relatively high concentrations (mM), in large excess of substrate with respect to metal complex. Dilution of substrate ligands below stoichiometry results in progressive decrease of signal enhancement, which precludes the direct application of SABRE to the NMR analysis of low concentration (mu M) solutions. Here, we show that the efficiency of SABRE at low substrate concentrations can be restored by addition of a suitable coordinating ligand to the solution. The proposed method allowed NMR detection below 1 mu M in a single scan.