Department of Chemistry, Jilin University, Changchun, 130021, People's Republic of China.
Langmuir. 2011 Sep 20;27(18):11609-15. doi: 10.1021/la202295b. Epub 2011 Aug 24.
A novel multifunctional microsphere with a fluorescent CdTe quantum dots (QDs) shell and a magnetic core (Fe(3)O(4)) has been successfully developed and prepared by a combination of the hydrothermal method and layer-by-layer (LBL) self-assembly technique. The resulting fluorescent Fe(3)O(4)@C@CdTe core/shell microspheres are utilized as a chemosensor for ultrasensitive Cu(2+) ion detection. The fluorescence of the obtained chemosensor could be quenched effectively by Cu(2+) 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-Volmer equation showed a good linear response (R(2) = 0.9957) in the range 1-10 μM with a quenching constant (K(sv)) of 4.9 × 10(4) M(-1). Most importantly, magnetic measurements showed that the Fe(3)O(4)@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.
一种具有荧光 CdTe 量子点（QDs）壳和磁性核（Fe(3)O(4)）的新型多功能微球，通过水热法和层层自组装技术的结合成功开发和制备。所得荧光 Fe(3)O(4)@C@CdTe 核/壳微球被用作超灵敏 Cu(2+)离子检测的化学传感器。所得化学传感器的荧光可以被 Cu(2+)离子有效猝灭。研究了猝灭机制，结果表明存在静态和动态猝灭过程。然而，静态猝灭是更为突出的一种。修饰后的 Stern-Volmer 方程在 1-10 μM 的范围内呈现出良好的线性响应（R(2) = 0.9957），猝灭常数（K(sv)）为 4.9 × 10(4) M(-1)。最重要的是，磁性测量表明，Fe(3)O(4)@C@CdTe 核/壳微球具有超顺磁性，它们可以在 10 秒内使用商用磁铁轻松分离和收集。这些结果不仅提供了解决 QDs 在实际传感应用中的尴尬问题的方法，而且还能够制造其他基于多功能纳米结构的混合纳米材料。
