“Our results in this study represent an NMR signal enhancement equivalent to that achieved in the pioneering experiments of Lucio Frydman and coworkers at the Weizmann Institute of Science, but using microwave-induced dynamic nuclear hyperpolarization in diamonds without the need for precise control over magnetic field and crystal alignment,” Pines says. “Room-temperature hyperpolarized diamonds open the possibility of NMR/MRI polarization transfer to arbitrary samples from an inert, non-toxic and easily separated source, a long sought-after goal of contemporary NMR/MRI technologies.”
December 17, 2015
Diamonds May Be the Key to Future NMR/MRI Technologies
The research group of Alex Pines has recorded the first bulk room-temperature NMR
hyperpolarization of carbon-13 nuclei in diamond in situ at arbitrary
magnetic fields and crystal orientations. (Photo by Christophoros Vassiliou)
(December 17, 2015) Berkeley Lab/UC Berkeley Researchers Increase NMR/MRI Sensitivity through Hyperpolarization of Nuclei in Diamond
Researchers with the U.S. Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab) and the University of California (UC) Berkeley have demonstrated that diamonds may hold the key to the future for nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI) technologies
In a study led by Alexander Pines, a senior faculty scientist with Berkeley Lab’s Materials Sciences Division and UC Berkeley’s Glenn T. Seaborg Professor of Chemistry, researchers recorded the first bulk room-temperature NMR hyperpolarization of carbon-13 nuclei in diamond in situ at arbitrary magnetic fields and crystal orientations. The signal of the hyperpolarized carbon-13 spins showed an enhancement of NMR/MRI signal sensitivity by many orders of magnitude above what is ordinarily possible with conventional NMR/MRI magnets at room temperature. Furthermore, this hyperpolarization was achieved with microwaves, rather than relying on precise magnetic fields for hyperpolarization transfer.
(From left) Claudia Avalos, Keunhong Jeong and Jonathan King were part of a team
led by Alex Pines that used microwaves to enhance NMR/MRI signal sensitivity
many orders of magnitude above what is ordinarily possible with conventional
NMR/MRI magnets at room temperature. (Photo by Roy Kaltschmidt)
The authors report the observation of a bulk nuclear spin polarization of six-percent, which is an NMR signal enhancement of approximately 170,000 times over thermal equilibrium. The signal of the hyperpolarized spins was detected in situ with a standard NMR probe without the need for sample shuttling or precise crystal orientation. The authors believe this new hyperpolarization technique should enable orders of magnitude sensitivity enhancement for NMR studies of solids and liquids under ambient conditions.