Cascaded FRET in Conjugated Polymer/Quantum Dot/Dye-Labeled DNA Complexes for DNA Hybridization Detection
Cascaded FRET in Conjugated Polymer/Quantum Dot/Dye-Labeled DNA Complexes for DNA Hybridization Detection
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DOI：
10.1021/nn901324y
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发表时间：
2009-12-01
期刊：
影响因子：
17.1
通讯作者：
Rogach, Andrey L.
中科院分区：
文献类型：
--
作者：
Jiang, Guoxin;Susha, Andrei S.;Rogach, Andrey L.
水溶性荧光共轭聚合物聚[9，9-双]的静电配合物（3 '-（（N，N-二甲基）-N-乙基铵）丙基）-2，7-芴-alt-1，4-亚苯基]二溴化物（PDFD）和水溶性CdTe量子点（QD）被设计为提供用于DNA杂交检测的级联FRET，PDFD在检测方案中具有两个功能：作为光捕获天线，它通过第一级FRET增强QD的发射，并反转QD的表面电荷的符号，从而提供带正电荷的表面以允许带负电荷的染料标记的DNA与所得复合物相互作用。这种相互作用导致第二级FRET到标记在探针DNA上的红外发射染料，提供了区分互补和非互补DNA的可靠的信号开启感测平台。一个详细的光谱研究提供了一个明确的描述，在设计的聚合物/量子点/DNA复合物的物理过程，提供了足够的潜力，进一步提高灵敏度和选择性。
Electrostatic complexes of a water-soluble fluorescent conjugated polymer, poly[9,9-bis(3'-((N,N-dimethyl)-N-ethylammonium)propyl)-2,7-fluorene-alt-1,4-phenylene]dibromide (PDFD), and water-soluble CdTe quantum dots (QDs) are designed to provide a cascaded FRET for DNA hybridization detection, PDFD has two functions in the detection scheme: as a light-harvesting antenna, it enhances the emission of QDs by the first level FRET and inverts the sign of the surface charge of QDs, thus providing a positively charged surface to allow negatively charged dye-labeled DNA to interact with the resulting complex. This interaction causes the second level FRET to infrared-emitting dye labeled on the probe DNA, providing a reliable signal-on sensing platform discriminating between complementary and non-complementary DNA. A detailed spectroscopic study offers a clear description of photophysical processes in the designed polymer/QD/DNA complex, providing ample potential for further sensitivity and selectivity improvements.