960化工网
Synthesis and self-assembly of hierarchical SiO2–QDs@SiO2 nanostructures and their photoluminescence applications for fingerprint detection and cell imaging
Wenjun Dong,Yan Cheng,Liang Luo,Xiaoyun Li,Lina Wang,Chunguang Li,Lifeng Wang
RSC Advances Pub Date : 08/18/2014 00:00:00 , DOI:10.1039/C4RA04925J
Abstract

Hierarchical SiO2–QDs@SiO2 (QDs = CdTe, PbTe or PbS) nanostructures have been prepared by an integrated synthesis and self-assembly strategy using 3-mercaptopropionic acid (MPA) to stabilize the QDs and NaOH to control the self-assembly of QDs on the SiO2 nanobead carriers. 3–10 nm QDs covered with a 1–2 nm SiO2 shells were separately embedded on the surface of 50 nm SiO2 nanobead carriers, resulting in hierarchical SiO2–QDs@SiO2 nanostructures. MPA and NaOH played important roles in the nucleation and growth of QDs, etching the SiO2 nanobead carriers to the colloidal surface, and the self-assembly of the QDs on viscous SiO2 nanobead carriers. The hierarchical SiO2–QDs@SiO2 nanostructures possess various advantages: (I) the growth of QDs and their self-assembly on SiO2 nanobead carriers were performed in a one-pot reaction by a facile aqueous phase refluxing approach; (II) the SiO2 shell with 1–2 nm in thickness can prevent the leakage of toxic Cd2+ or Pb2+ and avoid photobleaching or environmental pollution; (III) the surface of hierarchical SiO2–QDs@SiO2 nanostructures can be easily functionalized through silane-coupling chemistry. Because of the excellent photoluminescence and biocompatibility, the hierarchical SiO2–QDs@SiO2 nanostructures modified by carboxyl (–COOH) active group can be available for covalent coupling to various biomolecules, which have shown potential applications in fingerprint detection and in vivo cell imaging.

Graphical abstract: Synthesis and self-assembly of hierarchical SiO2–QDs@SiO2 nanostructures and their photoluminescence applications for fingerprint detection and cell imaging
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