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 μm over a 1 cm(2) field of view, and we show how the technique has the potential to yield images with combined high sensitivity (∼100 fg nanodiamond) AND high spatial resolution (∼100 μm) over organism-scale fields of view, features which are mutually exclusive in existing imaging modalities except at the shallowest imaging depths.