Sensitive single-color fluorescence "off-on" switch system for dsDNA detection based on quantum dots-ruthenium assembling dyads.
Sensitive single-color fluorescence "off-on" switch system for dsDNA detection based on quantum dots-ruthenium assembling dyads.
复制标题
DOI：
10.1016/j.bios.2013.12.059
复制
发表时间：
2014-06
影响因子：
12.6
通讯作者：
Rui Zhang;Dongxu Zhao;Hui-Guo Ding;Yan-Xiang Huang;Haizheng Zhong;Hai‐Yan Xie
中科院分区：
文献类型：
--
作者：
Rui Zhang;Dongxu Zhao;Hui-Guo Ding;Yan-Xiang Huang;Haizheng Zhong;Hai‐Yan Xie
由于快速、高灵敏度检测DNA的重要性，我们提出了一种基于新型单色荧光"关-开"开关系统的双链DNA检测方法。水溶性谷胱甘肽封端的碲化镉量子点（在605 nm处的发射）的制备利用量子点的容易调谐的发射特性。首先，量子点被Ru（phen）2（dppz）2+完全猝灭，形成量子点-Ru组装体。然后，在加入dsDNA的情况下，Ru（phen）2（dppz）2+从CdTe QD中除去，产生游离的CdTe QD和Ru-dsDNA复合物。它们都可以在相同的波长下被激发，并发出重叠的荧光。这种单色荧光"关-开"信号对dsDNA的浓度敏感。当使用0.5 nM CdTe量子点时，可检测到浓度为10 pg/mL的天然dsDNA，ssDNA、RNA或BSA对该体系无干扰，并对B型肝炎病毒（HBV）患者的dsDNA样品进行了检测。与荧光定量PCR检测结果比较，差异无统计学意义（P> 0. 05），对于DNA浓度较低的样本，该系统能提供更准确的检测结果，表明该"开关"系统可能具有临床应用价值。对于该系统，不需要化学缀合或标记探针，并且可以在不到半小时内检测未修饰的天然DNA靶标。因此，一个简单，快速，灵敏，低成本，高选择性和实用的双链DNA检测系统已被描述。
Due to the high importance of detecting DNA with both fast speed and high sensitivity, we proposed a new dsDNA detection method relying on a novel single-color fluorescence “off–on” switch system. Water-soluble glutathione capped CdTe QDs (emission at 605 nm) was prepared for taking advantage of the readily tunable emission property of QDs. Initially, QDs was completely quenched by the Ru(phen)2(dppz)2+, as the spontaneous formation of QDs-Ru assembling dyads. Then, in the case of the addition of dsDNA, the Ru(phen)2(dppz)2+was removed away from the CdTe QDs, producing free CdTe QDs and the Ru-dsDNA complex. Both of them could be excited at the same wavelength and emit overlaid fluorescence. This single-color fluorescence “off–on” signal was sensitive to the concentration of dsDNA. Native dsDNA with the concentration of 10 pg/mL could be detected when 0.5 nM CdTe QDs was used, and ssDNA, RNA or BSA had no interference on it. With this system, the dsDNA samples of hepatitis B virus (HBV) patients were tested. The results were in good agreement with those detected by fluorescence quantitative PCR (P>0.05), and for those samples with very low DNA concentrations, this system could provide more accurate results, demonstrating the possible clinical applicability of this “off–on” switch system. For this system, chemical conjugation or labeling of probes is not required, and unmodified native DNA targets could be detected in less than half an hour. Therefore, a simple, fast, sensitive, low cost, highly selective and practically applicable detection system for dsDNA has been described.