Observing the confinement potential of bacterial pore-forming toxin receptors inside rafts with nonblinking Eu(3+)-doped oxide nanoparticles.

We track single toxin receptors on the apical cell membrane of MDCK cells with Eu-doped oxide nanoparticles coupled to two toxins of the pore-forming toxin family: α-toxin of Clostridium septicum and ε-toxin of Clostridium perfringens. These nonblinking and photostable labels do not perturb the motion of the toxin receptors and yield long uninterrupted trajectories with mean localization precision of 30 nm for acquisition times of 51.3 ms.

High temperature strategy for oxide nanoparticle synthesis.

Compared with noble metals and quantum dots, dielectric complex oxide nanoparticles are significantly less popular due to their high crystallization temperature, making difficult their synthesis in the 10-100 nm range for which surface effects are reduced. We report here an original process permitting thermal annealing of complex oxide nanoparticles at high temperature without aggregation and growth. Thus, after thermal treatment, these annealed particles can be dispersed in water, leading to concentrated aqueous colloidal dispersions containing isolated highly crystalline particles.

Organic functionalization of luminescent oxide nanoparticles toward their application as biological probes.

Luminescent inorganic nanoparticles are now widely studied for their applications as biological probes for in vitro or in vivo experiments. The functionalization of the particles is a key step toward these applications, since it determines the control of the coupling between the particles and the biological species of interest. This paper is devoted to the case of rare earth doped oxide nanoparticles and their functionalization through their surface encapsulation with a functional polysiloxane shell.