Stable luminescent films and hollow spheres comprising CdTe nanoparticles

CdTe nanoparticles (CdTe-NPs) capped by 3-mercaptopropionic acid were synthesized and used to self-assemble (SA) with poly(allylamine hydrochloride) (PAH) layer-by-layer via electrostatic interaction to form luminescent multilayer films. Composite particles were prepared with polymer or SiO2 beads as the core and PAH/CdTe-NP SA films as the shell. The composite particles were dissolved out of the core with tetrahydrofuran (THF) or HF to prepare hollow spheres, then treated with 1-ethyl-3-(3-dimethyl-aminopropyl)-carbodiimide hydrochloride (EDC) in aqueous solution to form stable hollow spheres with a crosslinked PAH/CdTe-NP shell. Both the crosslinked films and the hollow spheres with a high luminescence are very stable in aqueous solutions at a wide range of pH.