State Key Laboratory Base of Eco-chemical Engineering, College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao, 266042, People's Republic of China.
Anal Chem. 2011 May 15;83(10):3873-80. doi: 10.1021/ac200383z. Epub 2011 Apr 19.
In this work, a novel dendrimer/CdSe-ZnS-quantum dot nanocluster (NC) was fabricated and used as an electrochemiluminescence (ECL) probe for versatile assays of cancer cells for the first time. A large number of CdSe-ZnS-quantum dots (QDs) were labeled on the NCs due to the many functional amine groups within the NCs, which could significantly amplify the QD's ECL signal. Capture DNA was specially designed as a high-affinity aptamer to the target cell; a novel ECL biosensor for cancer cells was directly accomplished by using the biobarcode technique to avoid cross-reaction. Moreover, magnetic beads (MBs) for aptamers immobilization were combined with the dendrimer/QD NCs probe for signal-on ECL assay of cancer cells, which greatly simplified the separation procedures and favored for the sensitivity improvement. In particular, a novel cycle-amplifying technique using a DNA device on MBs was further employed in the ECL assay of cancer cells, which greatly improved the sensitivity. To the best of our knowledge, this is the first study that the novel dendrimer/QD NCs probe combined with a DNA device cycle-amplifying technique was employed in the ECL assays of cells. Excellent discrimination against target and control cells is demonstrated, indicating that the ECL assays have great potential to provide a sensitive, selective, cost-effective, and convenient approach for early and accurate detection of cancer cells.
在这项工作中，我们首次制备了一种新型树状大分子/CdSe-ZnS-量子点纳米团簇（NC），并将其用作电化学发光（ECL）探针，用于多功能癌细胞分析。由于 NC 内含有大量的功能胺基，因此可以将大量的 CdSe-ZnS-量子点（QDs）标记在 NC 上，从而显著放大 QD 的 ECL 信号。捕获 DNA 被专门设计为目标细胞的高亲和力适体；通过使用生物条形码技术直接完成新型 ECL 生物传感器用于癌细胞的检测，从而避免了交叉反应。此外，用于适体固定的磁性珠（MBs）与树枝状大分子/QD NCs 探针结合，用于癌细胞的信号开启 ECL 分析，这大大简化了分离程序，有利于提高灵敏度。特别是，在癌细胞的 ECL 分析中进一步采用了一种基于 MBs 的 DNA 器件的新型循环放大技术，大大提高了灵敏度。据我们所知，这是首次将新型树状大分子/QD NCs 探针与 DNA 器件循环放大技术结合应用于细胞的 ECL 分析中。对靶细胞和对照细胞的出色区分表明，ECL 分析具有提供敏感、选择性、经济高效且方便的早期和准确检测癌细胞的巨大潜力。
