Direct Production of a Hyperpolarized Metabolite on a Microfluidic Chip.

Microfluidic systems hold great potential for the study of live microscopic cultures of cells, tissue samples, and small organisms. Integration of hyperpolarization would enable quantitative studies of metabolism in such volume limited systems by high-resolution NMR spectroscopy. We demonstrate, for the first time, the integrated generation and detection of a hyperpolarized metabolite on a microfluidic chip.

Towards large-scale steady-state enhanced nuclear magnetization with in situ detection.

Signal amplification by reversible exchange (SABRE) boosts NMR signals of various nuclei enabling new applications spanning from magnetic resonance imaging to analytical chemistry and fundamental physics. SABRE is especially well positioned for continuous generation of enhanced magnetization on a large scale; however, several challenges need to be addressed for accomplishing this goal. Specifically, SABRE requires (i) a specialized catalyst capable of reversible H activation and (ii) physical transfer of the sample from the point of magnetization generation to the point of detection (e.

parahydrogen-induced polarization: accumulating long-lived singlet order on methylene proton pairs.

In the majority of hydrogenative parahydrogen-induced polarization (PHIP) experiments, the hydrogen molecule undergoes pairwise addition to an unsaturated precursor to occupy vicinal positions on the product molecule. However, some ruthenium-based hydrogenation catalysts induce hydrogenation, leading to a reaction product in which the two hydrogen atoms are transferred to the same carbon centre, forming a methylene () group. The singlet order of parahydrogen is substantially retained over the hydrogenation reaction, giving rise to a singlet-hyperpolarized group.

Hyperpolarized fumarate via parahydrogen.

We produce hyperpolarized [1-C]fumarate in the proton nuclear spin singlet state by pairwise trans-addition of parahydrogen to a molecular precursor using a ruthenium-based catalyst in water. The proton singlet state is transformed into observable carbon magnetization by radiofrequency pulses to enhance the C signal by a factor of 1000 using 50% para-enriched hydrogen gas.