Nano- and Microscale Nuclear Magnetic Resonance Imaging

Traditional Nuclear Magnetic Resonance (NMR) is a key tool for determining the structure of organic and biological molecules. However, it suffers from low sensitivity, typically requiring millimetre-scale samples and large magnetic fields. This limitation hinders the analysis of mass-limited samples and prevents detailed NMR spectroscopy of single cells or individual proteins under near-physiological conditions, which is crucial for applications in metabolomics, disease diagnosis, and drug discovery targeting membrane proteins.

The development of NV-based magnetometry enables NMR spectroscopy and imaging at the nanoscale and microscale under ambient conditions. By placing a sample near NV centres in diamond, small sensing volumes ranging from (4 nm)³ to (10 µm)³ can be achieved. These quantum sensors provide a wide magnetic field sensing bandwidth, allowing detection of multiple spin species. High spectral resolution and sensitivity have been demonstrated, including single-proton detection and detection of small sample volumes.

NV-based NMR expands the capability for chemical analysis and structural determination to previously inaccessible nanoscale and microscale samples. This allows for in-depth studies of single-cell structure and function, metabolomics, and disease diagnosis. It also enables single-protein detection and the determination of membrane protein structures and dynamics, which could significantly aid drug discovery. The technology provides chemical contrast for high-resolution imaging and is being developed for higher sensitivity, resolution, and ease of use.