Regular papers

Comparison of the photoluminescence properties of semiconductor quantum dots and non-blinking diamond nanoparticles. Observation of the diffusion of diamond nanoparticles in living cells

¹ Laboratoire de Photonique Quantique et Moléculaire, Ecole Normale Supérieure de Cachan, UMR CNRS 8537, Cachan, France
² Laboratoire Structure et Activité des Biomolécules Normales et Pathologiques, Université Evry-Val-d’Essonne and INSERM U829, Evry, France
³ Laboratoire CEMHTI (Conditions Extrêmes et Matériaux : Haute Température et Irradiation), UPR CNRS 3079, Orléans, France

^* francois.treussart@ens-cachan.fr

Received: 9 December 2008

Abstract

Long-term observations of photoluminescence at the single-molecule level were until recently very difficult, due to the photobleaching of organic fluorophore molecules. Although inorganic semiconductor nanocrystals can overcome this difficulty showing very low photo-bleaching yield, they suffer from photoblinking. A new marker has been recently introduced, relying on diamond nanoparticles containing photoluminescent color centers. In this work we compare the photoluminescence of single quantum dots (QDs) to the one of nanodiamonds containing a single-color center. Contrary to other markers, photoluminescent nanodiamonds present a perfect photostability and no photoblinking. At saturation of their excitation, nanodiamonds photoluminescence intensity with a single NV-color center is only three times smaller than one of the single QDs. Moreover, the bright and stable photoluminescence of nanodiamonds allows wide field observations of single nanoparticles motion. We demonstrate the possibility of recording the trajectory of such single particle in culture cells.