Synthesis of aqueous CdTe quantum dots embedded silica nanoparticles and their applications as fluorescence probes

This paper presents the synthesis of aqueous CdTe QDs embedded silica nanoparticles by reverse microemulsion method and their applications as fluorescence probes in bioassay and cell imaging. With the aim of embedding more CdTe QDs in silica spheres, we use poly(dimethyldiallyl ammonium chloride) to balance the electrostatic repulsion between CdTe QDs and silica intermediates. By modifying the surface of CdTe/SiO2 composite nanoparticles with amino and methylphosphonate groups, biologically functionalized and monodisperse CdTe/SiO2 composite nanoparticles can be obtained. In this work, CdTe/SiO2 composite nanoparticles are conjugated with biotin-labeled mouse IgG via covalent binding. The biotin-labeled mouse IgG on the CdTe/SiO2 composite nanoparticles surface can recognize FITC-labeled avidin and avidin on the surface of polystyrene microspheres by protein–protein binding. Finally, the CdTe/SiO2 composite nanoparticles with secondary antibody are used to label the MG63 osteosarcoma cell with primary antibody successfully, which demonstrates that the application of CdTe/SiO2 composite nanoparticles as fluorescent probes in bioassay and fluorescence imaging is feasible.