Superparamagnetic Fe2O3 Beads-CdSe/ZnS quantum dots core-shell nanocomposite particles for cell separation
Superparamagnetic Fe2O3 Beads-CdSe/ZnS quantum dots core-shell nanocomposite particles for cell separation
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DOI：
10.1021/nl035010n
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发表时间：
2004-03-01
期刊：
影响因子：
10.8
通讯作者：
Rosenzweig, Z
中科院分区：
文献类型：
--
作者：
Wang, DS;He, JB;Rosenzweig, Z
本文报道了一种新型的纳米复合粒子的合成方法，该纳米复合粒子由聚合物包覆的γ-Fe 2 O3超顺磁性核和CdSe/ZnS量子点（QDs）壳组成。通过巯基-金属键的形成将单层量子点结合到巯基修饰的磁珠的表面以形成发光/磁性纳米复合颗粒。透射电子显微镜（TEM）和能量色散谱（EDS）被用来表征的尺寸，尺寸分布，和组成的发光/磁性纳米粒子。其平均直径为30 nm，尺寸变化为15%。纳米颗粒经羧基修饰以增加其在水溶液中的混溶性。与单个发光QD相比，观察到发光/磁性颗粒的发光量子产率降低3倍，并且它们的发射峰轻微蓝移。然而，颗粒是明亮的，并且使用常规荧光显微镜容易观察到。此外，没有观察到量子点的发光峰的明显加宽。发光/磁性纳米粒子容易从溶液中分离的磁性倾析使用永磁体。这种新粒子可用于包括发光检测和磁分离在内的各种生物分析测定。为了证明其效用，我们将抗环素E抗体固定在其表面上，并使用抗体包被的颗粒从血清溶液中分离MCF-7乳腺癌细胞。抗环素E抗体特异性结合细胞周期素，一种在乳腺癌细胞表面特异性表达的蛋白质。由于发光/磁性纳米复合颗粒的强发光，分离的乳腺细胞容易通过荧光成像显微镜观察。
This paper describes the synthesis of new nanocomposite nanoparticles that consist of polymer coated gamma-Fe2O3 superparamagnetic cores and CdSe/ZnS quantum dots (QDs) shell. A single layer of QDs was bound to the surface of thiol-modified magnetic beads through the formation of thiol-metal bonds to form luminescent/magnetic nanocomposite particles. Transmission electron microscopy (TEM) and energy disperse spectroscopy (EDS) were used to characterize the size, size distribution, and composition of the luminescent/magnetic nanoparticles. Their average diameter was 30 nm with a size variation of 15%. The nanoparticles were modified with carboxylic groups to increase their miscibility in aqueous solution. A 3-fold decrease in the luminescence quantum yield of the luminescent/magnetic particles and a slight blue shift in their emission peaks compared to individual luminescent QDs were observed. However, the particles were bright and were easily observed using a conventional fluorescence microscope. Additionally, no apparent broadening of the luminescence peak of the QDs could be seen. The luminescent/magnetic nanoparticles were easily separated from solution by magnetic decantation using a permanent magnet. The new particles could be used in a variety of bioanalytical assays involving luminescence detection and magnetic separation. To demonstrate their utility we immobilized anticycline E antibodies on their surface and used the antibody coated particles to separate MCF-7 breast cancer cells from serum solutions. Anticycline E antibodies bind specifically to cycline, a protein which is specifically expressed on the surface of breast cancer cells. The separated breast cells were easily observed by fluorescence imaging microscopy due to the strong luminescence of the luminescent/magnetic nanocomposite particles.