Diamond nanoparticles as photoluminescent nanoprobes for biology and   near-field optics
  We present results showing the potential of diamond nanoparticles with size less than 50 nm as photoluminescent nanoprobes for serving as stable point-like emitters attached at the tip apex of a near-field optical microscope to achieve enhanced spatial resolution. 
A. Cuche, Y. Sonnefraud, O. Faklaris, D. Garrot, J.-P. Boudou, T.   Sauvage, J.-F. Roch, F. Treussart, S. Huant