Sensitive, Efficient and Portable Analysis of Molecular Exchange Processes by Hyperpolarized Ultrafast NMR

Molecular exchange processes are ubiquitous in nature. Here, we introduce a method to analyze exchange processes by using low‐cost, portable, single‐sided NMR instruments. The inherent magnetic field inhomogeneity of the single‐sided instruments is exploited to achieve diffusion contrast of exchange sites and spatial encoding of 2D data. This so‐called ultrafast diffusion exchange spectroscopy method shortens the experiment time by two to four orders of magnitude. Furthermore, because full 2D data are measured in a single scan (in a fraction of a second), the sensitivity of the experiment can be improved by several orders of magnitude using so‐called nuclear spin hyperpolarization methods (in this case, dissolution dynamic nuclear polarization). As the first demonstration of the feasibility of the method in various applications, we show that the method enables quantification of intra‐ and extracellular exchange of water in a yeast cell suspension. A hyperpolarized ultrafast diffusion exchange spectroscopy method is introduced, which allows highly sensitive and efficient quantification of molecular exchange rates by using low‐cost, low‐field, single‐sided and portable NMR instruments. The method can be used to investigate exchange processes in many fields ranging from intra‐extracellular exchange of metabolites to atmospheric surfactant solutions.