SABRE polarized low field rare-spin spectroscopy

Area of Science:

• Nuclear Magnetic Resonance (NMR) Spectroscopy
• Hyperpolarization Techniques
• Spectroscopy

Background:

• High-field NMR is crucial for chemical and biomolecular structure analysis but requires expensive superconducting magnets.
• Low-field NMR offers a compact and accessible alternative but suffers from low signal sensitivity due to weak thermal polarization.
• Hyperpolarization methods can overcome low magnetic field limitations by significantly increasing nuclear spin polarization.

Purpose of the Study:

• To investigate the combination of Signal Amplification By Reversible Exchange (SABRE) with low-field, high-homogeneity electromagnets.
• To demonstrate the feasibility of achieving high-resolution NMR spectra at millitesla (mT) magnetic fields.
• To analyze the spin dynamics and spectral characteristics of SABRE-enhanced low-field NMR.

Main Methods:

• Utilized Signal Amplification By Reversible Exchange (SABRE) hyperpolarization.
• Employed high-homogeneity electromagnets operating at magnetic fields between 1 mT and 10 mT.
• Simulated spectral data and spin dynamics using the SPINACH software package.

Main Results:

• Achieved high-resolution 1H, 13C, 15N, and 19F NMR spectra with single-scan acquisition at mT fields.
• Observed complex spectra in the strong coupling regime, demonstrating chemical specificity.
• Simulations using SPINACH accurately reproduced experimental spectra and identified spin order terms.

Conclusions:

• The integration of SABRE hyperpolarization with low-field NMR instruments provides a significant sensitivity enhancement.
• This approach enables sensitive detection of rare spins with low gyromagnetic ratios at low magnetic fields.
• The developed method offers a powerful and accessible tool for chemical and biomolecular characterization.