Dynamic Nuclear Polarization (DNP) is a technique capable of boosting the sensitivity of an NMR experiment by two to three orders of magnitude. Currently, the method is routinely used in solid-state NMR experiments at frequencies up to 900 MHz. As a result, DNP enables scientists to conduct experiments that were unthinkable even a decade ago.

Enhancing the signal intensity in a solution-state NMR experiment using DNP is a much more challenging task. Due to the high dielectric losses of the solvent the sample can be easily destroyed by excessive microwave-induced sample heating. However, at low magnetic field strengths (e.g. 0.35 T, 14.5 MHz), many concepts from X-band EPR spectroscopy can be applied to build efficient ODNP resonators with minimal sample heating.

In this presentation we will summarize the instrument requirements for DNP spectroscopy with a focus on low-field NMR experiments. We will demonstrate 1D and 2D high-resolution, Overhauser DNP-enhanced NMR experiments at 0.35 T, and the application to study hydration dynamics of large bio-macromolecules, and its application to process monitoring or the studies of crude-oil samples.