Transition Metal Doping Reveals Link between Electron T1 Reduction and 13C Dynamic Nuclear Polarization Efficiency.

@article{Niedbalski2017TransitionMD,
  title={Transition Metal Doping Reveals Link between Electron T1 Reduction and 13C Dynamic Nuclear Polarization Efficiency.},
  author={Peter J. Niedbalski and Christopher Parish and Qing Wang and Zahra Hikmah Hayati and Likai Song and Andr{\'e} F Martins and A. Dean Sherry and Lloyd L Lumata},
  journal={The journal of physical chemistry. A},
  year={2017},
  volume={121 48},
  pages={
          9221-9228
        }
}
Optimal efficiency of dissolution dynamic nuclear polarization (DNP) is essential to provide the required high sensitivity enhancements for in vitro and in vivo hyperpolarized 13C nuclear magnetic resonance (NMR) spectroscopy and imaging (MRI). At the nexus of the DNP process are the free electrons, which provide the high spin alignment that is transferred to the nuclear spins. Without changing DNP instrumental conditions, one way to improve 13C DNP efficiency is by adding trace amounts of… Expand
12 Citations
The effect of Ho3+ doping on 13C dynamic nuclear polarization at 5 T.
TLDR
It is found that adding a small amount of Ho-DOTA in the sample preparation not only enhances the 13C polarization but also decreases the buildup time. Expand
Gadolinium Effect at High-Magnetic-Field DNP: 70% 13C Polarization of [U-13C] Glucose Using Trityl.
TLDR
Performing ESR measurements under actual DNP conditions, it is shown that the trityl electron spin resonance (ESR) features, crucial for an efficient dynamic nuclear polarization (DNP) process, are sample-composition-dependent and experimental evidence is provided that gadolinium doping not only shortens the trithl electronspin-lattice relaxation time but also modifies the radical g-tensor. Expand
Dynamic nuclear polarization of carbonyl and methyl 13C spins of acetate using 4-oxo-TEMPO free radical.
TLDR
The results suggest that the intramolecular environment of 13C spins plays a prominent role in determining the 13C DNP efficiency, while the solid phase 13C T1 relaxation of these samples is dominated by the paramagnetic effect due to the relatively high concentration of free radicals. Expand
Effects of glassing matrix deuteration on the relaxation properties of hyperpolarized 13C spins and free radical electrons at cryogenic temperatures.
TLDR
While the solid-phase 13C DNP signals are dependent upon the changes in total nuclear Zeeman heat capacity, the 13C relaxation effects are related to 2H/1H nuclear spin diffusion-assisted 13C polarization leakage in addition to the dominant paramagnetic relaxation contribution of free radical centers. Expand
A spin-thermodynamic approach to characterize spin dynamics in TEMPO-based samples for dissolution DNP at 7 T field.
TLDR
DNP profiles and dynamics under frequency-modulated microwave irradiation illustrate the expected increase in coupling between electrons with increasing radical concentration, at high field (7 T) increased coupling is seen. Expand
NMR Spectroscopy Unchained: Attaining the Highest Signal Enhancements in Dissolution Dynamic Nuclear Polarization.
TLDR
This Perspective presents viewpoints regarding the key elements needed to maximize the NMR signal enhancements in dissolution DNP, from the very core of the DNP process at cryogenic temperatures, DNP instrumental conditions, and chemical tuning in sample preparation to current developments in minimizing hyperpolarization losses during the dissolution transfer process. Expand
Metal-Chelated Polymer Nanodiscs for NMR Studies.
TLDR
The results suggest that polymer nanodiscs functionalized with paramagnetic tags can be used to speed-up data acquisition from lipid bilayer samples and also to provide structural information from water-soluble biomolecules. Expand
Use of paramagnetic systems to speed-up NMR data acquisition and for structural and dynamic studies.
TLDR
This review discusses how to set up an optimal paramagnetic relaxation enhancement (PRE) system to effectively reduce the T1 relaxation times avoiding significant broadening of NMR signals and how to preserve the enhancements when dissolution DNP is implemented. Expand
Lipid-nanodiscs formed by paramagnetic metal chelated polymer for fast NMR data acquisition.
TLDR
This study shows how the introduction of paramagnetic tags on the outer belt of polymer-nanodiscs can be used to speed-up data acquisition by significantly reducing the spin-lattice relaxation (T1) times with minimum-to-no alteration of the spectral quality. Expand
Direct measurement of the triple spin flip rate in dynamic nuclear polarization.
TLDR
It is shown that in this case DNP is due to the cross-effect (CE) and that the build-up rate can be quantitatively interpreted as the rate of the triple spin flips responsible for the CE. Expand
...
1
2
...

References

SHOWING 1-10 OF 71 REFERENCES
Influence of Dy3+ and Tb3+ doping on 13C dynamic nuclear polarization.
TLDR
Dy 3+ doping and Tb3+ doping have a beneficial impact on C13 DNP both in the solid and liquid states, and that Tb 3+ in particular could be used as a potential alternative to Gd3+ in C13 dissolution DNP experiments. Expand
13C Dynamic Nuclear Polarization Using a Trimeric Gd3+ Complex as an Additive.
TLDR
The use of a trimeric gadolinium complex as a dopant in 13C DNP samples to improve the DNP signals in the solid-state and W-band electron paramagnetic resonance (EPR) data have revealed that 3-Gd doping significantly reduces the electron T1 of the trityl OX063 free radical but produces negligible changes in the EPR spectrum, reminiscent of the results with monomeric Gd3+-complex doping. Expand
Enhanced Efficiency of 13C Dynamic Nuclear Polarization by Superparamagnetic Iron Oxide Nanoparticle Doping.
TLDR
The overall results suggest that the commercially-available and FDA-approved Feraheme is a highly efficient DNP enhancer that could be readily translated for use in clinical applications of dissolution DNP. Expand
Electron spin resonance studies of trityl OX063 at a concentration optimal for DNP.
TLDR
The ESR properties of trityl OX063 reported here may provide insights into the efficiency of DNP of low-γ nuclei performed at various magnetic fields, from 0.35 T to 12 T. Expand
The effect of glassing solvent deuteration and Gd3+ doping on 13C DNP at 5 T
We report the influence of glassing solvent deuteration and Gd3+ doping on 13C dynamic nuclear polarization (DNP) nuclear magnetic resonance (NMR) performed on [1-13C] sodium acetate at B0 = 5 T andExpand
Dynamic Nuclear Polarization with Trityls at 1.2 K
Abstract.Dynamic nuclear polarization (DNP) at 3.35 T and 1.2 K is characterized for [1-13C]pyruvic acid and the paramagnetic agent OX063Me. This paramagnetic agent belongs to a class of organicExpand
Effect of lanthanide ions on dynamic nuclear polarization enhancement and liquid‐state T1 relaxation
TLDR
Results indicate that polarization with free lanthanides and subsequent chelation during dissolution produces the highest polarization enhancement while minimizing liquid‐state relaxation. Expand
Dynamic Nuclear Polarization in the solid state: a transition between the cross effect and the solid effect.
TLDR
To determine the dominant DNP mechanisms responsible for the enhancement of the nuclear signals, electron and nuclear spin-lattice relaxation rates, enhancement buildup times and microwave (MW) swept DNP spectra were measured as a function of temperature and MW irradiation strength. Expand
The effect of Gd on trityl-based dynamic nuclear polarisation in solids.
TLDR
Changes in the electron depolarisation profile are a combined result of shortening of the longitudinal and transverse electron spin relaxation times, as well as an increase in the eSD rate and in the effective electron-proton anisotropic hyperfine interaction parameter. Expand
Impact of Ho(3+)-doping on (13)C dynamic nuclear polarization using trityl OX063 free radical.
TLDR
The results here suggest that Ho(3+)-doping is advantageous over Gd(3+) in terms of preservation of hyperpolarized state-an important aspect to consider for in vitro and in vivo NMR or imaging (MRI) experiments where a considerable preparation time is needed to administer the hyperPolarized (13)C liquid. Expand
...
1
2
3
4
5
...