Towards room temperature magnetic sensing of a single electron spin in biological systems

We report on recent progress of room temperature sensing for biological applications using nitrogen-vacancy (NV) centers in diamond. First, we discuss progress made toward measuring the magnetic field of a single electron spin using as a sensor the electron spin of an NV in bulk diamond. This is approached by attaching commercially available nitroxide spin labels to the functionalized surface of the bulk diamond, and using a nearby NV center as a sensor. In addition, we present progress toward the study of functionalized nanodiamonds in living cells used as single spin label probes of local magnetic field environments. The ability to sense magnetic fields with sub-micrometer resolution with sensitivity capable of detecting a single electron spin is of major importance to the biological sciences.