通过仲氢衍生极化的分子间转移实现小分子的稳健核超极化
Robust nuclear hyperpolarization of small molecules through intermolecular transfer of parahydrogen-derived polarization
中文总结 AI 辅助
研究旨在解决超极化技术局限，核心方法是基于PHIP构建PHIPNOE平台，通过分子间极化转移实现对多种目标分子的超极化，主要贡献为拓展了超极化技术应用范围，提升了NMR信号检测灵敏度。
中文摘要 AI 辅助
超极化技术的出现提高了NMR信号灵敏度，但大多方法存在局限。本文介绍PHIPNOE平台，基于仲氢诱导极化（PHIP），通过定制PHIP产生极化‘源分子’，经自旋极化诱导核Overhauser效应（SPINOE）将极化分配给目标分子。研究了化学影响并建立预测模型。该方法无需修改NMR光谱仪，增强效果可重复，实现了单次多维NMR等应用。
英文摘要
The recent advent of hyperpolarization techniques, which can enhance NMR signals by several orders of magnitude relative to thermally polarized samples, has enabled applications traditionally out of reach due to the inherently low sensitivity of NMR techniques. However, a high barrier to entry remains, as most hyperpolarization approaches either require complex instrumentation or are applicable only to a relatively small set of molecules. Here we introduce PHIPNOE, a platform that directly addresses both limitations. PHIPNOE is based on parahydrogen-induced polarization (PHIP), which is well-established as a scalable route to hyperpolarization requiring minimal instrumentation, but has been mostly restricted to molecules that undergo specific chemical reactions. We overcome this barrier by tailoring PHIP to create highly polarized, highly concentrated solutions of one specific molecule, which acts as an intermediate source of polarization. This 'source molecule' then distributes polarization to a broad range of target molecules mixed into the solution, via the spin polarization-induced nuclear Overhauser effect (SPINOE). We investigate chemical influences on PHIPNOE, and develop a predictive model to estimate enhancement based on molecular mass and T1 relaxation times. A complete run from PHIP hyperpolarization to PHIPNOE polarization transfer and signal detection takes less than one minute, the approach does not require any modifications to the NMR spectrometer, and enhancements are repeatable across molecular classes. PHIPNOE thus enables applications including single-shot multidimensional NMR, real-time monitoring of dynamic processes, and, with 300-fold signal amplification demonstrated on a benchtop spectrometer, practical low-field NMR, where we show enhanced sensitivity in detecting per- and polyfluoroalkyl substances (PFAS).
