Molecular Imaging by Optically Detected Electron Spin Resonance of Nitrogen-Vacancies in Nanodiamonds

We propose a novel biomedical imaging technique, called nanodiamond imaging, that noninvasively records the three-dimensional distribution of biologically tagged nanodiamonds in vivo. Our technique performs optically detected electron spin resonance of nitrogen-vacancy centers in nanodiamonds, a nontoxic nanomaterial that is easily biologically functionalized. We demonstrate the feasibility of the technique by imaging multiple nanodiamond targets within pieces of chicken breast; it is the first demonstration of imaging within scattering tissue by optically detected magnetic resonance. We achieve a sensitivity equivalent to 740 pg of nanodiamond in 100 s of measurement time and a spatial resolution of 800 mu m over a 1 cm(2) field of view, and we show how the technique has the potential to yield images with combined high sensitivity (similar to 100 fg nanodiamond) AND high spatial resolution (similar to 100 mu m) over organism-scale fields of view, features which are mutually exclusive in existing imaging modalities except at the shallowest imaging depths.