Rare earth element detection via optically detected magnetic resonance using nitrogen vacancies in nanodiamonds

Quantum sensors provide sensitivity that is unattainable by classical sensors, allowing detection of the weak magnetic fields generated by the electron spins of rare earth elements (REEs). A specific electronic spin state in nitrogen vacancy (NV) centers in nanodiamonds has energies that are highly sensitive to the change in local electromagnetic fields, temperature, and pressure, and thus can be used to engineer sensors for the detection of these physical quantities. In this study, we conduct optically detected magnetic resonance (ODMR) using NV centers in nanodiamonds to detect the presence of nearby REEs. We observed an additional Zeeman splitting of ~1.17 MHz/mT per μM of Gd relative to the Zeeman splitting observed in the absence of Gd, revealing the potential to use this technique for REE detection.