Nuclear magnetic resonance (NMR) spectroscopy is a powerful analytical technique with routine applications throughout the chemical and physical sciences. The magnetic resonance effect derives from a relatively weak interaction between certain atomic nuclei and external magnetic fields. While this interaction can be used to obtain detailed molecular-level information, it leads to a relatively weak, field-dependent NMR signal response. Standard laboratory NMR spectrometers feature a magnetic field in the range of 7 – 23 T that is generated by a superconducting magnet. While advantageous in terms of maximising sensitivity, the need for a large superconducting magnet limits the use of NMR spectroscopy for applications such as industrial process monitoring, where cost, size, and portability are critical. In recent years, there has been an increased interest in cheaper and more portable NMR and MRI instruments, from benchtop NMR spectrometers that operate in the 1-2T regime down to ultra-low-field detectors that work in the Earth’s magnetic field and below. These low-cost and portable NMR spectrometers have opened up new possibilities for using NMR spectroscopy outside of the standard laboratory environment. However, there are limitations associated with performing NMR spectroscopy in weaker magnetic fields. The low sensitivity of NMR is exacerbated at low magnetic field and spectral dispersion reduces linearly with magnetic field, leading to a loss in chemically discriminating information.
One route to overcoming the sensitivity limitation of low-field NMR is to use hyperpolarisation. Hyperpolarisation is a general term for a range of methods that boost the signal-to-noise ratio of NMR spectroscopy by essentially increasing the fraction of ‘visible’ nuclei in the experiment, often by several orders of magnitude. Of particular interest to this project are liquid-state Overhauser Dynamic Nuclear Polarisation, where the source of polarisation is an unpaired electron, and signal amplification by reversible exchange (SABRE), where the source of hyperpolarisation is the singlet nuclear isomer of H2, parahydrogen. These methods are of particular interest because they can provide renewable hyperpolarisation, without significantly compromising the size, cost and portability of the low-field NMR approach. The goal of this project is to explore the relative advantages of these two hyperpolarisation approaches for signal enhancement in ultra-low magnetic fields (e.g. the Earth’s magnetic field) for different classes of molecules and different potential applications.
This project will suit someone with a background in physics or chemistry who is interested in developing fundamental skills in magnetic resonance including hyperpolarisation and low-field NMR. This project will involve the design and implementation of hyperpolarisation experiments with low-field (µT – mT) detection, data analysis and instrumentation development, where appropriate.
The project will be carried out under the supervision of Dr Meghan Halse. Throughout the project, the student will gain advanced training in low-field NMR and hyperpolarisation with additional skills in the theoretical basis of NMR, advanced data analysis and NMR instrumentation. This project will be carried out within the broader context of hyperpolarisation research at York. Therefore, in addition to meetings within the Halse research group, the student will also be exposed to the wider range of expertise within the Centre for Hyperpolarisation in Magnetic Resonance (CHyM) on topics including NMR spectroscopy, hyperpolarisation, MR theory, photochemistry, catalysis and kinetics.
All Chemistry research students have access to our innovative Doctoral Training in Chemistry (iDTC): cohort-based training to support the development of scientific, transferable and employability skills: https://www.york.ac.uk/chemistry/postgraduate/idtc/
The Department of Chemistry holds an Athena SWAN Gold Award and is committed to supporting equality and diversity for all staff and students. The Department strives to provide a working environment which allows all staff and students to contribute fully, to flourish, and to excel: https://www.york.ac.uk/chemistry/ed/
You should expect hold or expect to achieve the equivalent of at least a UK upper second class degree in Chemistry or a related subject. Please check the entry requirements for your country: https://www.york.ac.uk/study/international/your-country/
This project is available to students from any country who can fund their own studies. The Department of Chemistry at the University of York is pleased to offer Wild Fund Scholarships. Applications are welcomed from those who meet the PhD entry criteria from any country outside the UK. Scholarships will be awarded on supervisor support, academic merit, country of origin, expressed financial need and departmental strategy. For further details and deadlines, please see our website: View Website