Acta Chimica Sinica ›› 2011, Vol. 69 ›› Issue (23): 2843-2850.DOI: 10.6023/A1106031 Previous Articles     Next Articles

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龚会平, 刘绍璞, 殷鹏飞, 闫曙光, 范小青, 何佑秋*   

  1. (西南大学化学化工学院 重庆 400715)
  • 投稿日期:2011-06-03 修回日期:2011-07-19 发布日期:2011-08-15
  • 通讯作者: 何佑秋

Study on the Interaction between CdTe Quantum Dot-Acridine Orange-Calf Thymus DNA by Fluorescence Reversible Control

GONG Hui-Ping, LIU Shao-Pu, YIN Peng-Fei, YAN Shu-Guang, FAN Xiao-Qing, HE You-Qiu   

  1. (School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715)
  • Received:2011-06-03 Revised:2011-07-19 Published:2011-08-15

Glutathione (GSH)-capped CdTe quantum dots (GSH-CdTe QDs) were synthesized in aqueous solution. In pH 7.4 Tris-HCl buffer medium, acridine orange (AO) was adsorbed to the surfaces of GSH-CdTe QDs via electrostatic attraction and formed ground state complex, which resulted in the quenching of the fluorescence of GSH-CdTe QDs. Adding ctDNA to GSH-CdTe QDs-AO system leaded to the fluorescence intensity of GSH-CdTe QDs recover, which can be explained by that the addition of ctDNA to the system induced AO to dissociate from the surface of GSH-CdTe QDs and embed into its double helix structure. According to the fluorescence quencher and restoration for GSH-CdTe QDs, fluorescence reversible control of QDs was realized. The fluorescence intensity change of GSH-CdTe QDs-AO system aroused by the addition of ctDNA was proportional to the ctDNA concentration in a certain range, and its detection limit was 0.13 ng•mL-1. Based on it, the simple, rapid, accurate and sensitive methods had been proposed to determine ctDNA. The interaction of GSH-CdTe QDs-AO-ctDNA was studied by resonance Rayleigh scattering (RRS), absorption spectra and image of atomic force microscopy. The interaction mechanism was discussed and corresponding model of interaction was built.

Key words: CdTe quantum dot, acridine orange, calf thymus DNA, fluorescence reversible control