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Updated: Aug 1, 2025
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Dissolution Dynamic Nuclear Polarization Instrumentation for Real-time Enzymatic Reaction Rate Measurements by NMR
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Solid-Effect Dynamic Nuclear Polarization in Viscous Liquids at 9.4 T Using Narrow-Line Polarizing Agents
Andrei A Kuzhelev1, Vasyl Denysenkov1, Iram M Ahmad2
1Institute of Physical and Theoretical Chemistry and Center for Biomolecular Magnetic Resonance, Goethe University Frankfurt am Main, Max von Laue Straße 7, 60438 Frankfurt am Main, Germany.
Journal of the American Chemical Society
|April 27, 2023
Summary
Dynamic nuclear polarization (DNP) significantly boosts nuclear magnetic resonance (NMR) sensitivity in viscous liquids. This study demonstrates over 50-fold 1H NMR enhancement using specific radicals in glycerol.
Area of Science:
- Magnetic Resonance Spectroscopy
- Physical Chemistry
- Chemical Physics
Background:
- Dynamic nuclear polarization (DNP) enhances nuclear magnetic resonance (NMR) sensitivity.
- DNP is well-established in solid and liquid states but less explored in viscous media.
- Viscous media present unique challenges and opportunities for DNP implementation.
Purpose of the Study:
- To investigate the feasibility and effectiveness of DNP in viscous liquids.
- To achieve significant 1H NMR sensitivity enhancement in glycerol.
- To demonstrate the potential of this DNP approach for chemical and biological applications.
Main Methods:
- Utilized narrow-line polarizing agents (BDPA and triarylmethyl radicals) in glycerol.
- Employed a microwave/RF double-resonance probehead at 9.4 T and 315 K.
- Analyzed DNP enhancement profiles and dependence on experimental parameters (microwave power, temperature, concentration).
Main Results:
- Achieved a 1H DNP enhancement factor exceeding 50 in viscous glycerol.
- Observed DNP enhancement profiles consistent with the solid effect mechanism.
- Successfully obtained hyperpolarized 1H NMR spectra of tripeptides, triglycine, and glypromate.
Conclusions:
- Demonstrated efficient DNP in viscous media, significantly enhancing 1H NMR sensitivity.
- The developed method shows promise for sensitive analysis of biomolecules and small organic compounds.
- This approach expands the applicability of DNP to challenging viscous environments.
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