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Updated: May 22, 2025

Dissolution Dynamic Nuclear Polarization Instrumentation for Real-time Enzymatic Reaction Rate Measurements by NMR
Published on: February 23, 2016
Room-Temperature Pulsed Dynamic Nuclear Polarization at 7 T
Alexander A Nevzorov1, Sergey Milikisiyants1, Antonin Marek1
1Department of Chemistry, North Carolina State University, 2620 Yarbrough Drive, Raleigh, North Carolina 27695-8204, United States.
Abstract:
Pulsed dynamic nuclear polarization (DNP) can enhance NMR signals by more than 2 orders of magnitude and is applicable to spin systems with short-lived electronic polarization. Recently, several pulsed DNP sequences were demonstrated at low magnetic fields. However, pulsed DNP at magnetic fields of modern NMR spectrometers (7 T and above) necessitates addressing major technical challenges for generating sufficiently high mm-wave B1e amplitudes to match the nuclear Larmor frequencies. Here we describe a first-of-its-kind ESR/NMR spectrometer for pulsed DNP and phase-sensitive electronic detection operating at 7 T magnetic field. Generation of B1e fields with amplitudes of ca. 75 MHz was made possible by employing a pulsed extended interaction klystron and piezo-tunable photonic-band gap resonators with unloaded quality factors Q ≈ 1500. Room-temperature NOVEL DNP yielded natural-abundance 13C NMR signal gains of up to 800 for a 30 μm thick crystal of a synthetic diamond. Simultaneous coherent manipulation of the electronic and nuclear spins was demonstrated by 13C-detected electron Rabi nutations.
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