Preparation and characterization of overcoated II-VI quantum dots.
A convenient route for the synthesis of high-quality overcoated II-VI quantum dots (QDs) is reported in this paper. Simple salts, such as Cd(Ac)2 and Zn(Ac)2 were used to replace organometallics, whose disadvantage is obvious. Size-tunable core/shell structured QDs (CdSe/ZnS, CdSe/CdS, etc.) were synthesized. They were of narrow size distribution and had good monodispersivity and photoluminescence (PL) properties. The spectrum was symmetrical and sharp-pointed (with the full width at half-maximum (fwhm) of about 20-30 nm). The quantum yield (QY) was improved to 60-80% from 20-30% for bare QDs and remained stable at least for 6 months. The primary overcoated QDs were modified with biomacromolecules by a direct mechanical rubbing strategy, which is very simple and fast. The results obtained by UV-vis, PL, atomic force microscopy (AFM), and fluorescence microscopy imaging showed that the modified QDs were of good fluorescent and monodisperse characteristics. They are likely to be used further for biological labels.
Xie
Hai-Yan
HY
College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, P. R. China.
Liang
Jian-Gong
JG
Liu
Yi
Y
Zhang
Zhi-Ling
ZL
Pang
Dai-Wen
DW
He
Zhi-Ke
ZK
Lu
Zhe-Xue
ZX
Huang
Wei-Hua
WH
D019187:Cadmium Compounds / Q000032:analysis / Q000737:chemistry*; D020099:Coated Materials, Biocompatible / Q000032:analysis / Q000737:chemistry*; D003460:Crystallization / Q000379:methods; D008422:Materials Testing; D008856:Microscopy, Fluorescence / Q000379:methods*; D010316:Particle Size; D045663:Quantum Dots; D018036:Selenium Compounds / Q000032:analysis / Q000737:chemistry*; D012710:Serum Albumin, Bovine / Q000032:analysis / Q000737:chemistry* / Q000648:ultrastructure*; D013440:Sulfides / Q000032:analysis / Q000737:chemistry*; D017967:Zinc Compounds / Q000032:analysis / Q000737:chemistry*
D019187:Cadmium Compounds; D020099:Coated Materials, Biocompatible; D018036:Selenium Compounds; D013440:Sulfides; D017967:Zinc Compounds; C034939:cadmium sulfide; D012710:Serum Albumin, Bovine; C044696:zinc selenide