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Zero and ultra-low field nuclear magnetic resonance

Periodic Reporting for period 1 - ZULF (Zero and ultra-low field nuclear magnetic resonance)

Reporting period: 2018-02-01 to 2020-01-31

Nuclear magnetic resonance (NMR) is a powerful technique employed in numerous diverse areas of modern science and industry from medicine to quantum computing. Its most well-known application, the Magnetic Resonance Imaging (MRI), has become so embedded in public consciousness, that the number of MRI scanners per capita is often treated as a measure of quality of a healthcare system in a given country. Conventional MRI requires very strong magnets. These are very expensive, heavy and put limitations of the use of the techniques on patients with cochlear implants or cardiac pacemakers.
Recent progress in physics and chemistry have enabled detection of NMR signals at Zero and Ultra-Low magnetic Fields (ZULF). The ZULF Innovative Training Network (ITN) is dedicated to developing, exploring, and applying methods of NMR in this regime and through this research provide training to 11 Early Stage Researchers (ESR). In the ITN framework, the world-leading experts in diverse fields and disciplines comprising the ZULF consortium gained the ability to effectively collaborate and fully exploit their unique individual teaching methods, domain knowledge, and practical expertise.
The main scientific objective of the project is to go beyond the state-of-the-art in NMR under ZULF conditions by pushing the boundary in hyperpolarization and magnetometry research. By the end of the action, this will result in demonstrations of advanced sensor technologies and protocols for chemical substance recognition, as well as novel schemes for more fundamental research, such as searches for the 5th force and parity non-conservation in chiral molecules, some of the burning questions of the modern science.
ZULF touches essentially every area in which conventional NMR and MRI is having an impact. It will lead to strengthening of European innovation capacity by numerous links to practical applications. These will boost competitiveness of several branches of European economy including the food industry, drug innovation and monitoring, chemical engineering, chemical-process control.
Despite being still at a relatively early stage the project generated several breakthroughs, significantly enhancing the capabilities of ZULF NMR. Laurynas Dagys from the University of Southampton (SOTON) elaborated the theoretical framework of ZULF NMR. Before his contribution the description was only partial. He furthermore created a dedicated add-on to broadly used NMR calculation software – Spin Dynamica – that is already in use by other consortium members in their research.
We are investigating nearly all known hyperpolarization schemes. James Ellis from the Johannes Gutenberg University (JGU) in Mainz studied polarization by parahydrogen (PHIP) under ZULF by the so-called magnetic-field sweeping. Together with the International Tomography Center in Novosibirsk, he also demonstrated that ZULF NMR may be used for reaction monitoring of heterogeneous samples in metal containers. At the University of York (UoY), Aminata Sakho worked on a different approach to ZULF using parahydrogen, called Signal Amplification By Reversible Exchange (SABRE). The research resulted in a demonstration of NMR at the Earth magnetic field, with polarization of up to 3%, over a hundred times larger than in high-field NMR spectrometers.
Quentin Chappuis from the University Claude Bernard in Lyon (UCBL) explored the so-called Dynamic Nuclear Polarization (DNP) technique, where the polarization of electrons, which can be very strongly polarized, is being transferred to the nuclei, thus enhancing polarization of the latter by orders of magnitude. First DNP-hyperpolarized spectra at zero field were obtained by him working with James Eills from JGU. Kirill Sheberstov, also from JGU demonstrated first photochemically-induced DNP under ZULF conditions. Finally, Anjusha Vijayakumar from the University of Ulm (UULM) and Domingo Olivares from the Italian Institute of Technology (IIT) shown a novel technique, exploring the so-called spin echo, that enhanced sensitivity of the magnetic-field measurement in sensors using nanodiamond samples, and enabled detection of signals of truly individual molecules.
Vladimir Kontul and Seyma Alcicek, ESRs from the Jagiellonian University (UJ) worked on the development of an optical atomic magnetometer of simpler and hence more reliable construction, with enhanced usefulness for ZULF NMR. Their activities resulted in construction of a sensor using of a single light beam and a single photodiode, which is characterized by the sensitivity of 30 fT/Hz1/2 and 300 Hz bandwidth, parameters exceeding those of commercially available optical sensors. Portable and potentially commercial ZULF NMR apparatus is currently under development.
The University of Torino (UNITO) ESR Oksana Bondar used PHIP-hyperpolarized [1-13C] pyruvate to investigate the metabolism in three prostate cancer cell lines characterized by different aggressiveness. It was concluded that parahydrogen-hyperpolarized metabolites can be used for monitoring metabolism in-cells and in-vivo.
Significant effort was also put on ZULF NMR using conventional thermally-polarized samples (I.e. polarized using permanent magnet). These activities focus on measurement of spectra of new molecules not being explored in ZULF NMR by UJ Seyma Alcicek, and also on characterization of liquids in multiphase materials across the micro to millitesla field range done by Sven Bodenstedt from the Institute of Photonic Sciences (ICFO). These will have important implications for imaging techniques under ZULF.
As we continue enhancing the capabilities of ZULF NMR new research avenues open, such as investigations of parity-nonconservation, a fundamental property of Nature that is expected to play a crucial role in understanding of excess of matter over antimatter in early Universe. Some initial stages were already performed in this context by Kiril Sherbesov at JGU. Simultaneously, research exploiting the so-called spin-gravity coupling, conducted at UJ and led by Seyma Alcicek will be directed toward the 5th force searches. That is a hypothetical, yet theoretically predicted, force that may be related to the origins of dark matter or dark energy.
Significant efforts will also be made to detect ZULF NMR spectra of truly single molecules. To enable this, UULM and IIT will focus on further development of the measurement technique that will increase the sensitivity of their nanodiamond-based sensors. This will lead to the first observations of dynamics of a single nuclear system at very weak or truly zero magnetic field. Independently, the work led by ICFO in collaboration with UJ will aim at selective addressing specific spins, manipulation of intramolecular interactions and studies of dynamics of isolated nuclei under ZULF conditions.
Many groups (JGU, UNITO, UoY, SOTON, UCBL, UJ) will now work on combining hyperpolarization with ZULF NMR. The proof-of-principle experiment has already been performed. New compounds are investigated that can be used at ZULF to increase our understanding of the dynamics of the processes and the role of various experimental factors. This activity, led by UJ in collaboration with JGU and ICFO, should lead to construction of a small and portable experimental system with software dedicated to pattern recognition, that will allow for chemical fingerprinting, and hence open means for commercialization of ZULF NMR and its real-life applications.
Logos of project beneficiaries
Commemorative photo form the network meeting in Lyon
ZULF NMR project logo