Nanoscale NMR Spectroscopy and Imaging of Multiple Nuclear Species
Figure 4: Optical MRI of multi-species sample with sub-micrometre structure. [Reprinted by permission from Macmillan Publishers Ltd: Nature Nanotechnology ©2015]
Nuclear magnetic resonance (NMR) spectroscopy and magnetic resonance imaging (MRI) provide non-invasive information about multiple nuclear species in bulk matter, with wide-ranging applications from basic physics and chemistry to biomedical imaging. However, the spatial resolution of conventional NMR and MRI is limited to several micrometres even at large magnetic fields (>1 T), which is inadequate for many frontier scientific applications such as single-molecule NMR spectroscopy and in vivo MRI of individual biological cells. A promising approach for nanoscale NMR and MRI exploits optical measurements of nitrogen–vacancy (NV) colour centres in diamond, which provide a combination of magnetic field sensitivity and nanoscale spatial resolution unmatched by any existing technology, while operating under ambient conditions in a robust, solid-state system. Recently, single, shallow NV centres were used to demonstrate NMR of nanoscale ensembles of proton spins, consisting of a statistical polarization equivalent to ∼100–1,000 spins in uniform samples covering the surface of a bulk diamond chip. In a new study published in Nature Nanotechnology, a team of scientists led by Dr. Ronald Walsworth realize nanoscale NMR spectroscopy and MRI of multiple nuclear species (1H, 19F, 31P) in non-uniform (spatially structured) samples under ambient conditions and at moderate magnetic fields (∼20 mT) using two complementary sensor modalities. The team consisted of researchers from Harvard Physics, Chemistry and Chemical Biology, CfA, SEAS, and Hebrew University, and included, among others, grad student Igor Lovchinsky, research scientists Alexander Sushkov and Huiliang Zhang, and Professors Mikhail Lukin, Hongkun Park, and Amir Yacoby.
See S.J. DeVience, L.M. Pham, I. Lovchinsky, A.O. Sushkov, N. Bar-Gill, C. Belthangady, F. Casola, M. Corbett, H. Zhang, M.Lukin, H. Park, A. Yacoby & R.L. Walsworth, "Nanoscale NMR spectroscopy and imaging of multiple nuclear species," Nature Nanotechnology doi:10.1038/nnano.2014.313 (published online 5 Jan 2015).