Intracellular Relaxometry, Challenges, and Future Directions

properties on the basis of their magnetic surroundings. Since optical signals can be detected more sensitively than small magnetic signals, this technique allows unprecedented sensitivity. Recently, NV center-based relaxometry has been used for measurements in living cells with subcellular resolution. The aim of this Outlook is to identify challenges in the field, including controlling the location of sensing particles, limitations in reproducibility, and issues arising from biocompatibility. We further provide an outlook and point to new directions in the field. These include new diamond materials with NV centers, other defects, or even entirely new materials that might replace diamonds. We further discuss new and more challenging samples, such as tissues or even entire organisms, that might be investigated with NV centers. Then, we address future challenges that have to be resolved in order to achieve this goal. Finally, we discuss new quantities that could be measured with NV centers in the future.

Automated summary

This article introduces the NV center-based relaxometry technique, which utilizes the sensitivity of optical signals to detect properties based on the magnetic surroundings. The challenges of this technique, including controlling the location of sensing particles, reproducibility limitations, and biocompatibility issues, are discussed. The article also provides an outlook on new directions and future challenges in the field.