期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2020
卷号：117
期号：30
页码：17558-17563
DOI：10.1073/pnas.2004121117
出版社：The National Academy of Sciences of the United States of America
摘要：We report hyperpolarized Xe signal advancement by metal-organic framework (MOF) entrapment (Hyper-SAME) in aqueous solution. The 129 Xe NMR signal is drastically promoted by entrapping the Xe into the pores of MOFs. The chemical shift of entrapped 129 Xe is clearly distinguishable from that of free 129 Xe in water, due to the surface and pore environment of MOFs. The influences from the crystal size of MOFs and their concentration in water are studied. A zinc imidazole MOF, zeolitic imidazole framework-8 (ZIF-8), with particle size of 110 nm at a concentration of 100 mg/mL, was used to give an NMR signal with intensity four times that of free 129 Xe in water. Additionally, Hyper-SAME is compatible with hyperpolarized 129 Xe chemical exchange saturation transfer. The 129 Xe NMR signal can be amplified further by combining the two techniques. More importantly, Hyper-SAME provides a way to make detection of hyperpolarized 129 Xe in aqueous solution convenient and broadens the application area of MOFs.
关键词：MOFs ; NMR ; Hyper-CEST ; MRI ; signal advancement
