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Updated: May 22, 2025
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Dissolution Dynamic Nuclear Polarization Instrumentation for Real-time Enzymatic Reaction Rate Measurements by NMR
Published on: February 23, 2016
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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.
The Journal of Physical Chemistry Letters
|May 20, 2025
Summary
Pulsed dynamic nuclear polarization (DNP) at high magnetic fields (7 T) was achieved using a novel ESR/NMR spectrometer. This technique enhanced natural-abundance 13C NMR signals by up to 800-fold in synthetic diamond.
Area of Science:
- Magnetic Resonance
- Spectroscopy
- Quantum Information Science
Background:
- Pulsed dynamic nuclear polarization (DNP) significantly enhances Nuclear Magnetic Resonance (NMR) signals.
- Previous pulsed DNP methods were limited to low magnetic fields.
- High magnetic fields (≥7 T) present challenges in generating sufficient microwave (mm-wave) fields (B1e) for pulsed DNP.
Purpose of the Study:
- To develop and demonstrate a novel Electron Spin Resonance (ESR)/NMR spectrometer for pulsed DNP at 7 T.
- To overcome technical challenges in generating high-amplitude mm-wave B1e fields.
- To achieve significant NMR signal enhancement for natural-abundance 13C in synthetic diamond.
Main Methods:
- Designed and constructed a first-of-its-kind ESR/NMR spectrometer operating at 7 T.
- Employed a pulsed extended interaction klystron and piezo-tunable photonic-band gap resonators (Q ≈ 1500) to generate B1e fields of ~75 MHz.
- Utilized phase-sensitive electronic detection for enhanced sensitivity.
Main Results:
- Achieved room-temperature Nuclear Overhauser Effect (NOE) dynamic nuclear polarization (DNP) with signal gains up to 800 for a 30 μm synthetic diamond crystal.
- Demonstrated simultaneous coherent manipulation of electron and nuclear spins via 13C-detected electron Rabi nutations.
- Successfully generated high-amplitude mm-wave B1e fields required for pulsed DNP at 7 T.
Conclusions:
- The developed 7 T ESR/NMR spectrometer enables high-performance pulsed DNP.
- This advancement significantly enhances NMR sensitivity for challenging samples like natural-abundance 13C.
- The system allows for coherent control of coupled electron-nuclear spin systems.
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