Maximising the sharing of the Nottingham DNP MAS NMR Facility

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The Nottingham DNP MAS Facility was established in 2015 via an EPSRC strategic equipment application jointly submitted by the Schools of Physics, Chemistry and Life Sciences. Since its implementation access to the Facility could be gained through two different routes. Costed access required the payment of the FEC operating costs (£1k/day) and a free access route was implemented to allow users to run feasibility and plot projects. Pilot and feasibility studies are particularly important for DNP MAS NMR because the sensitivity gain provided by this method crucially depend on the optimization of the sample preparation. The percentage of access time through the costed route has increased from initially 2% to 31% in the second year, but this is not enough to operate the Facility sustainably after the end of August 2018 when current EPSRC funding for the free access route will run out. A case is made to extent the EPSRC contribution to the operating costs for another two years, so that equipment sharing can be maximised by increasing the user group using targeted actions and increasing the conversion of feasibility studies into grant proposals submitted to RCUK.Solid-state magic angle spinning (MAS) NMR spectroscopy in combination with Dynamic Nuclear Polarization (DNP) has recently emerged as a powerful technique for characterizing the structure and dynamics of amorphous or heterogeneous materials and biological systems at the atomic level. The large sensitivity gain relative to conventional solid-state NMR allows experiments to be performed that are currently not feasible because of time constraints. Examples include the detection of insensitive isotopes at low natural abundance (such as 17O) and correlation experiments between pairs of nuclei (such as 13C or 15N). In addition NMR signals from molecules absorbed on surfaces or from proteins in intact cells can be detected for the first time. DNP is based on the transfer of the significantly larger electron spin polarisation from paramagnetic centres to the nuclear spins of interest using a strong microwave field. A critical step for success is the optimal sample preparation in which the material under investigation is mixed with organic radicals. The huge potential of DNP MAS NMR has led to a recent surge of research activity aimed at gaining a more detailed understanding of the underpinning physics of DNP and optimizing experimental protocols for sample preparation.