After reviewing briefly the concept of zero magnetic field nuclear magnetic resonance (ZULF NMR), Dmitry Budker describes a recent proposal to use single NV center sensors to measure single nuclear spins in ZULF NMR [1].
Figure taken from [1], An optical trap might hold a single molecule in a ZULF NMR setup. A single NV center, a few nanometers below it, acts as the detection method. Figure build by John W. Blanchard.
References: Extreme nuclear magnetic resonance: zero field, single spins, dark matter…, Dmitry Budker, arXiv:1905.08851 (2019).