Layer-by-Layer Assembled Fe3O4@C@CdTe Core/Shell Microspheres as Separable Luminescent Probe for Sensitive Sensing of Cu2+ Ions

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• 作者：Hengguo Wang ; Lei Sun ; Yapeng Li ; Xiaoliang Fei ; Mingda Sun ; Chaoqun Zhang ; Yaoxian Li ; Qingbiao Yang
• 刊名：Langmuir
• 出版年：2011
• 出版时间：September 20, 2011
• 年：2011
• 卷：27
• 期：18
• 页码：11609-11615
• 全文大小：932K
• 年卷期：v.27,no.18(September 20, 2011)
• ISSN：1520-5827

文摘

A novel multifunctional microsphere with a fluorescent CdTe quantum dots (QDs) shell and a magnetic core (Fe₃O₄) has been successfully developed and prepared by a combination of the hydrothermal method and layer-by-layer (LBL) self-assembly technique. The resulting fluorescent Fe₃O₄@C@CdTe core/shell microspheres are utilized as a chemosensor for ultrasensitive Cu²⁺ ion detection. The fluorescence of the obtained chemosensor could be quenched effectively by Cu²⁺ ions. The quenching mechanism was studied and the results showed the existence of both static and dynamic quenching processes. However, static quenching is the more prominent of the two. The modified Stern鈥揤olmer equation showed a good linear response (R² = 0.9957) in the range 1鈥?0 渭M with a quenching constant (K_sv) of 4.9 脳 10⁴ M^鈥?. Most importantly, magnetic measurements showed that the Fe₃O₄@C@CdTe core/shell microspheres were superparamagnetic and they could be separated and collected easily using a commercial magnet in 10 s. These results obtained not only provide a way to solve the embarrassments in practical sensing applications of QDs, but also enable the fabrication of other multifunctional nanostructure-based hybrid nanomaterials.