Label-free sensing of thrombin based on quantum dots and thrombin binding aptamer.
Label-free sensing of thrombin based on quantum dots and thrombin binding aptamer.
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DOI：
10.1016/j.talanta.2013.01.003
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发表时间：
2013-03
期刊：
影响因子：
6.1
通讯作者：
Xiangyu Zhang;Ruoxin Hu;Na Shao
中科院分区：
文献类型：
--
作者：
Xiangyu Zhang;Ruoxin Hu;Na Shao
A facile and sensitive label-free approach for detection of thrombin based on CdTe quantum dots (QDs) and thrombin binding aptamer (TBA) is presented. The crude QDs can be “activated” with fluorescence enhancement by adding extra Cd2+to the solution in basic medium. As a result, the positively charged Cd2+-activating CdTe QDs could interact with the negatively charged TBA, leading to fluorescence quenching. When thrombin was added, TBA was induced to form a G-quadruplex structure and combined specifically with its target, releasing the QDs with a recovery of the fluorescence intensity. The sensing approach is based on the strongly specific interactions between TBA and thrombin over the electrostatic interactions between TBA and positively charged QDs. Based on the fluorescence enhancement of QDs, selective detection of thrombin was successfully achieved. A linear response for thrombin was observed in the range from 1.4nM to 21nM with a detection limit of 0.70nM.
