Preparation of fluorescent SiO2 particles with single CdTe nanocrystal cores by the reverse microemulsion method

Highly fluorescent CdTe@SiO2 core-shell-structured spheres (see Figure) are prepared via hydrolysis and condensation of tetraethyl orthosilicate in water-in-oil emulsions. Systematic results reveal that the electrostatic interactions between negatively charged CdTe nanocrystals (NCs) and silica intermediates play a critical role in determining the final structures of the resultant particles. Following this mechanism, the number of CdTe NCs encapsulated in silica spheres is successfully tuned.