High-Quality Fluorescent Nanodiamonds for Bio-Quantum Sensing

Fluorescent nanodiamonds (NDs) containing nitrogen-vacancy (NV) centers have attaracted much attention for their use in precise nanoscale sensing in biology, like measuring minute temperature changes [1], [2] or detecting reactive oxygen species inside cells [3]. However, the sensitivity of these sensors depends strongly on the spin properties of the NV centers. Improving both the NV spin properties and optical brightness at the same time has been difficult because of the substitutional nitrogen atoms that are not converted into NV centers.