IQST Grad School Project

Hyperpolarized nano-diamonds as molecular imaging and sensing probes for MRI

Project Description:

The ability to recognize molecular processes using novel imaging techniques is crucial for medicine, biology and biochemistry in the 21st century. Non-invasively detecting small numbers of molecular probes, to help image particular targets or pathways in vivo, is currently undergoing a technological revolution. Recent breakthroughs in molecular hyperpolarization proved a more than 10,000-fold increase in sensitivity on conventional magnetic resonance imaging (MRI) systems, thus providing insight into previously unseen metabolic processes. They variety of molecules which can be used in hyperpolarized MRI is unfortunately very limited, as the signal increase decays with the T1 relaxation time of the molecule. Our project goal is the development and realization of a novel hyperpolarization scheme for nano-diamonds (NDs), using the unique properties of Nitrogen-Vacancy (NV) centres. Nanodiamond present three attractive advantages as hyperpolarized molecular markers: (1) Diamond 13C spins have extraordinarily long relaxation times (up to hours in bulk diamonds), (2) NV centres are optically active, and can reach over 90% polarization even at room temperature, and (3) Nanodiamonds are biologically inert. However, transferring the polarization from the NV centres to the nuclear spins present several significant challenges compared to typical dynamic nuclear polarization (DNP) systems. Namely the large zero-field splitting and random orientation of the NV centres, and the relatively weak interaction with the surrounding nuclear spins. In this project we will develop polarization schemes which can overcome the challenges of DNP in nanodiamonds and achieve a high room-temperature hyperpolarization of nanodiamond ensembles

Selection of recent publications:

Resonance-inclined optical nuclear spin polarization of liquids in diamond structures Q. Chen, I. Schwarz, F. Jelezko, A. Retzker, and M. B. Plenio Phys. Rev. B 93, 060408(R) (2016)

Optically induced dynamic nuclear spin polarisation in diamond J. Scheuer, I. Schwarz, Q. Chen, D. Schulze-Sünninghausen, P. Carl, P. Höfer, A. Retzker, H. Sumiya, J. Isoya, B. Luy, M.B. Plenio, B. Naydenov, and F. Jelezko New Journal of Physics 18, 013040 (2016)

Optical hyperpolarization of 13C nuclear spins in nanodiamond ensembles Chen, I. Schwarz, F. Jelezko, A. Retzker, M.B. Plenio Phys. Rev. B 92, 184420 (2015)