Department of Chemical Sciences , Università degli Studi di Padova , via Marzolo 1 , 35131 Padova , Italy.
J Am Chem Soc. 2019 Mar 27;141(12):4870-4877. doi: 10.1021/jacs.8b13225. Epub 2019 Feb 28.
Nanoparticle-assisted "NMR chemosensing" is an experimental protocol that exploits the selective recognition abilities of nanoparticle receptors to detect and identify small molecules in complex mixtures by nuclear Overhauser effect magnetization transfer. Although the intrinsic sensitivity of the first reported protocols was modest, we have now found that water spins in long-lived association at the nanoparticle monolayer constitute an alternative source of magnetization that can deliver a remarkable boost of sensitivity, especially when combined with saturation transfer experiments. The approach is general and can be applied to analyte-nanoreceptor systems of different compositions. In this work, we provide an account of the new method and we propose a generalized procedure based on a joint water-nanoparticle saturation to further upgrade the sensitivity, which ultimately endows selective analyte detection down to the micromolar range on standard instrumentation.
纳米粒子辅助的“NMR 化学感应”是一种实验方案，利用纳米粒子受体的选择性识别能力，通过核 Overhauser 效应磁化转移来检测和识别复杂混合物中的小分子。尽管最初报道的方案的固有灵敏度不高，但我们现在发现，在纳米粒子单层中长寿命缔合的水分子构成了磁化的替代来源，可以提供显著的灵敏度提升，特别是与饱和转移实验结合使用时。该方法具有通用性，可应用于不同组成的分析物-纳米受体系统。在这项工作中，我们提供了对新方法的说明，并提出了一种基于水-纳米粒子联合饱和的广义程序，以进一步提高灵敏度，最终在标准仪器上实现了对微摩尔范围内的选择性分析物检测。
