Luminescent Nanoparticles of Silica-Encapsulated Cadmium–Tellurium (CdTe) Quantum Dots with a Core–Shell Structure: Preparation and Characterization
✍ Scribed by Haitao Dong; Yan Liu; Zhiqiang Ye; Wenzhu Zhang; Guilan Wang; Zhiguang Liu; Jingli Yuan
- Publisher
- John Wiley and Sons
- Year
- 2009
- Tongue
- German
- Weight
- 536 KB
- Volume
- 92
- Category
- Article
- ISSN
- 0018-019X
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✦ Synopsis
Abstract
Water‐soluble thioglycolic acid (TGA)‐capped CdTe quantum dots (QDs) were synthesized in aqueous medium, and then encapsulated in a silica nanosphere by copolymerization of the TGA‐capped CdTe conjugated with (3‐aminopropyl)triethoxysilane (APS‐CdTe conjugate), free (3‐aminopropyl)triethoxysilane (=3‐(triethoxysilyl)propan‐1‐amine; APS), and tetraethyl orthosilicate (TEOS) in a H~2~O‐in‐oil reverse microemulsion consisting of Triton X‐100, octanol, cyclohexane, and H~2~O in the presence of aqueous NH~3~ solution. The characterizations by transmission electron microscopy (TEM) and luminescence spectroscopy shows that the luminescent nanoparticles are monodisperse, spherical, and uniform in size, ca. 50 nm in diameter with a regular core–shell structure. In addition, primary amino groups directly introduced to the nanoparticle's surface by using free APS in the nanoparticle preparation enable the nanoparticles to be used easier as a biolabel. The effects of pH and metal cations on the luminescence of the nanoparticles also suggest that the new nanoparticles could be useful probes for luminescent sensings of pH and Cu^2+^ ion.