Hamachi, Tomoyuki, and Nobuhiro Yanai. “Recent Developments in Materials and Applications of Triplet Dynamic Nuclear Polarization.” Progress in Nuclear Magnetic Resonance Spectroscopy 142–143 (August 2024): 55–68.
https://doi.org/10.1016/j.pnmrs.2024.05.001.
Dynamic nuclear polarization (DNP) is a method for achieving high levels of nuclear spin polarization by transferring spin polarization from electrons to nuclei by microwave irradiation, resulting in higher sensitivity in NMR/MRI. In particular, DNP using photoexcited triplet electron spins (triplet-DNP) can provide a hyper polarized nuclear spin state at room temperature and in low magnetic field. In this review article, we highlight recent developments in materials and instrumentation for the application of triplet-DNP. First, a brief history and principles of triplet-DNP will be presented. Next, important advances in recent years will be outlined: new materials to hyperpolarize water and biomolecules; high-sensitivity solution NMR by dissolution triplet-DNP; and strategies for further improvement of the polarization. In view of these developments, future directions to widen the range of applications of triplet-DNP will be discussed.