NMR quantum sensing using Nitrogen–Vacancy Centers in Diamond

Elucidating molecular structure at the single- to few-molecule level is an important topic in analytical chemistry, biochemistry, and molecular biology. The nitrogen–vacancy (NV) center in diamond is a promising sensing tool to achieve this resolution for nanoscale nuclear magnetic resonance (NMR) spectroscopy and imaging.

In this talk, we report on recent strategies to improve NMR spectroscopy methods by new measurement schemes with NV centers. These allow us to physically map the nuclear spin signals of individual ¹³C atoms and to measure their inter-nuclear couplings at room temperature. Individual ¹³C atoms in the atomistic environment of the NV center serve as an ideal test bed for the long-term goal of imaging individual molecules that are attached to the diamond surface. Towards this goal, we report on our ongoing work on bringing NV centers close to the surface and preparing surfaces in a controlled manner. We chemically functionalize the diamond surface with monolayers of fluorinated molecules and show that ¹⁹F NMR signals can be detected using single NVs. We give an outlook on the steps needed to perform NMR measurements at the single-molecule level and to expand the suite of characterization methods necessary for spin mapping above the diamond surface.