Characterization of frequency-chirped dynamic nuclear polarization in rotating solids

Patrick T. Judge; Erika L. Sesti; Nicholas Alaniva; Edward P. Saliba; Lauren E. Price; Chukun Gao; Thomas Halbritter; Snorri Th Sigurdsson; George B. Kyei; Alexander B. Barnes

doi:10.1016/j.jmr.2020.106702

Characterization of frequency-chirped dynamic nuclear polarization in rotating solids

Patrick T. Judge, Erika L. Sesti, Nicholas Alaniva, Edward P. Saliba, Lauren E. Price, Chukun Gao, Thomas Halbritter, Snorri Th Sigurdsson, George B. Kyei, Alexander B. Barnes^*

^*Corresponding author for this work

Research output: Contribution to journal › Article › peer-review

2 Citations (Scopus)

Abstract

Continuous wave (CW) dynamic nuclear polarization (DNP) is used with magic angle spinning (MAS) to enhance the typically poor sensitivity of nuclear magnetic resonance (NMR) by orders of magnitude. In a recent publication we show that further enhancement is obtained by using a frequency-agile gyrotron to chirp incident microwave frequency through the electron resonance frequency during DNP transfer. Here we characterize the effect of chirped MAS DNP by investigating the sweep time, sweep width, center-frequency, and electron Rabi frequency of the chirps. We show the advantages of chirped DNP with a trityl-nitroxide biradical, and a lack of improvement with chirped DNP using AMUPol, a nitroxide biradical. Frequency-chirped DNP on a model system of urea in a cryoprotecting matrix yields an enhancement of 142, 21% greater than that obtained with CW DNP. We then go beyond this model system and apply chirped DNP to intact human cells. In human Jurkat cells, frequency-chirped DNP improves enhancement by 24% over CW DNP. The characterization of the chirped DNP effect reveals instrument limitations on sweep time and sweep width, promising even greater increases in sensitivity with further technology development. These improvements in gyrotron technology, frequency-agile methods, and in-cell applications are expected to play a significant role in the advancement of MAS DNP.

Original language	English
Article number	106702
Journal	Journal of Magnetic Resonance
Volume	313
DOIs	https://doi.org/10.1016/j.jmr.2020.106702
Publication status	Published - Apr 2020

Bibliographical note

Funding Information:
The research reported in this publication was supported by an NIH Director’s New Innovator Award [grant number DP2GM119131 ], an NSF CAREER Award [grant number DBI-1553577 ], a Camille Dreyfus Teacher-Scholar Award, a Deutsche Forschungsgemeinschaft (DFG) Postdoctoral Fellowship [ 414196920 ], and the University of Iceland Research Fund. We also thank Faith Scott, Sarah Overall, Asif Equbal, and Songi Han for helpful discussions.

Publisher Copyright:
© 2020

Other keywords

Dynamic nuclear polarization (DNP)
Frequency-chirped DNP
Gyrotron
Magic angle spinning NMR
Pulsed DNP

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10.1016/j.jmr.2020.106702

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@article{6dea8a414b144270a00d603a568f9c7a,

title = "Characterization of frequency-chirped dynamic nuclear polarization in rotating solids",

abstract = "Continuous wave (CW) dynamic nuclear polarization (DNP) is used with magic angle spinning (MAS) to enhance the typically poor sensitivity of nuclear magnetic resonance (NMR) by orders of magnitude. In a recent publication we show that further enhancement is obtained by using a frequency-agile gyrotron to chirp incident microwave frequency through the electron resonance frequency during DNP transfer. Here we characterize the effect of chirped MAS DNP by investigating the sweep time, sweep width, center-frequency, and electron Rabi frequency of the chirps. We show the advantages of chirped DNP with a trityl-nitroxide biradical, and a lack of improvement with chirped DNP using AMUPol, a nitroxide biradical. Frequency-chirped DNP on a model system of urea in a cryoprotecting matrix yields an enhancement of 142, 21% greater than that obtained with CW DNP. We then go beyond this model system and apply chirped DNP to intact human cells. In human Jurkat cells, frequency-chirped DNP improves enhancement by 24% over CW DNP. The characterization of the chirped DNP effect reveals instrument limitations on sweep time and sweep width, promising even greater increases in sensitivity with further technology development. These improvements in gyrotron technology, frequency-agile methods, and in-cell applications are expected to play a significant role in the advancement of MAS DNP.",

keywords = "Dynamic nuclear polarization (DNP), Frequency-chirped DNP, Gyrotron, Magic angle spinning NMR, Pulsed DNP",

author = "Judge, {Patrick T.} and Sesti, {Erika L.} and Nicholas Alaniva and Saliba, {Edward P.} and Price, {Lauren E.} and Chukun Gao and Thomas Halbritter and Sigurdsson, {Snorri Th} and Kyei, {George B.} and Barnes, {Alexander B.}",

note = "Funding Information: The research reported in this publication was supported by an NIH Director{\textquoteright}s New Innovator Award [grant number DP2GM119131 ], an NSF CAREER Award [grant number DBI-1553577 ], a Camille Dreyfus Teacher-Scholar Award, a Deutsche Forschungsgemeinschaft (DFG) Postdoctoral Fellowship [ 414196920 ], and the University of Iceland Research Fund. We also thank Faith Scott, Sarah Overall, Asif Equbal, and Songi Han for helpful discussions. Publisher Copyright: {\textcopyright} 2020",

year = "2020",

month = apr,

doi = "10.1016/j.jmr.2020.106702",

language = "English",

volume = "313",

journal = "Journal of Magnetic Resonance",

issn = "1090-7807",

publisher = "Academic Press Inc.",

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T1 - Characterization of frequency-chirped dynamic nuclear polarization in rotating solids

AU - Judge, Patrick T.

AU - Sesti, Erika L.

AU - Alaniva, Nicholas

AU - Saliba, Edward P.

AU - Price, Lauren E.

AU - Gao, Chukun

AU - Halbritter, Thomas

AU - Sigurdsson, Snorri Th

AU - Kyei, George B.

AU - Barnes, Alexander B.

N1 - Funding Information: The research reported in this publication was supported by an NIH Director’s New Innovator Award [grant number DP2GM119131 ], an NSF CAREER Award [grant number DBI-1553577 ], a Camille Dreyfus Teacher-Scholar Award, a Deutsche Forschungsgemeinschaft (DFG) Postdoctoral Fellowship [ 414196920 ], and the University of Iceland Research Fund. We also thank Faith Scott, Sarah Overall, Asif Equbal, and Songi Han for helpful discussions. Publisher Copyright: © 2020

PY - 2020/4

Y1 - 2020/4

N2 - Continuous wave (CW) dynamic nuclear polarization (DNP) is used with magic angle spinning (MAS) to enhance the typically poor sensitivity of nuclear magnetic resonance (NMR) by orders of magnitude. In a recent publication we show that further enhancement is obtained by using a frequency-agile gyrotron to chirp incident microwave frequency through the electron resonance frequency during DNP transfer. Here we characterize the effect of chirped MAS DNP by investigating the sweep time, sweep width, center-frequency, and electron Rabi frequency of the chirps. We show the advantages of chirped DNP with a trityl-nitroxide biradical, and a lack of improvement with chirped DNP using AMUPol, a nitroxide biradical. Frequency-chirped DNP on a model system of urea in a cryoprotecting matrix yields an enhancement of 142, 21% greater than that obtained with CW DNP. We then go beyond this model system and apply chirped DNP to intact human cells. In human Jurkat cells, frequency-chirped DNP improves enhancement by 24% over CW DNP. The characterization of the chirped DNP effect reveals instrument limitations on sweep time and sweep width, promising even greater increases in sensitivity with further technology development. These improvements in gyrotron technology, frequency-agile methods, and in-cell applications are expected to play a significant role in the advancement of MAS DNP.

AB - Continuous wave (CW) dynamic nuclear polarization (DNP) is used with magic angle spinning (MAS) to enhance the typically poor sensitivity of nuclear magnetic resonance (NMR) by orders of magnitude. In a recent publication we show that further enhancement is obtained by using a frequency-agile gyrotron to chirp incident microwave frequency through the electron resonance frequency during DNP transfer. Here we characterize the effect of chirped MAS DNP by investigating the sweep time, sweep width, center-frequency, and electron Rabi frequency of the chirps. We show the advantages of chirped DNP with a trityl-nitroxide biradical, and a lack of improvement with chirped DNP using AMUPol, a nitroxide biradical. Frequency-chirped DNP on a model system of urea in a cryoprotecting matrix yields an enhancement of 142, 21% greater than that obtained with CW DNP. We then go beyond this model system and apply chirped DNP to intact human cells. In human Jurkat cells, frequency-chirped DNP improves enhancement by 24% over CW DNP. The characterization of the chirped DNP effect reveals instrument limitations on sweep time and sweep width, promising even greater increases in sensitivity with further technology development. These improvements in gyrotron technology, frequency-agile methods, and in-cell applications are expected to play a significant role in the advancement of MAS DNP.

KW - Dynamic nuclear polarization (DNP)

KW - Frequency-chirped DNP

KW - Gyrotron

KW - Magic angle spinning NMR

KW - Pulsed DNP

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DO - 10.1016/j.jmr.2020.106702

M3 - Article

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AN - SCOPUS:85081992520

SN - 1090-7807

VL - 313

JO - Journal of Magnetic Resonance

JF - Journal of Magnetic Resonance

M1 - 106702

ER -

Characterization of frequency-chirped dynamic nuclear polarization in rotating solids

Abstract

Bibliographical note

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