Hyperpolarized Xe NMR signal advancement by metal-organic framework entrapment in aqueous solution

Significance Hyperpolarized 129 Xe NMR/MRI is a useful method for diagnosis of diseases of the respiratory system. However, the sensitive detection of specific compounds in blood remains a challenge because of the weak 129 Xe signal in aqueous solution. We developed a way, Hyper-SAME, to promote the 129 Xe signal in aqueous solution. The 129 Xe signal intensity is four times beyond that of free 129 Xe in water and 200 times better than the benchmark molecular cage, cryptophane-A, in its saturated aqueous solution. Additionally, the hyperpolarized 129 Xe signal can be amplified further by combining Hyper-SAME with hyperpolarized 129 Xe chemical exchange saturation transfer.