Badoni, Saumya, Pierrick Berruyer, Lorenzo Niccoli, Anne Lesage, and Lyndon Emsley. “Maximizing Relayed 1H Hyperpolarization Transfer by Slow-Fast MAS NMR Spectroscopy.” The Journal of Physical Chemistry A, August 9, 2024, acs.jpca.4c02452.
https://doi.org/10.1021/acs.jpca.4c02452.
1H-detected dynamic nuclear polarization (DNP)-enhanced fast magic angle spinning (MAS) NMR experiments provide unprecedented sensitivity tostudy the structure and dynamics inadvanced materials and biomolecules. However, inrelayed DNP experiments, DNP enhancements decrease with faster MAS rates, which isdetrimental for sensitivity. The decrease isbecause 1H-1Hspin diffusion rates aresignificantly reduced atfast MAS frequencies. Toimprove sensitivity atthese fast MAS rates, here, we propose tocombine fast polarization build-up byrelay atslow MAS rate with high-resolution 1HNMR atfastMAS foracquisition. Weperform experiments on L-histidine·HCl·H2Owith MAS rates ofupto65kHz using a0.7mm DNP probe at18.8 Tand 100 K.We obtain a35% improvement insensitivity in experiments where the sample ispolarized at20kHz MAS and where the signal isacquired at60kHz MAS.