DNA在纳米金修饰聚2,6-吡啶二甲酸膜电极上的固定杂交及与3-氨基酚噁嗪的相互作用

Immobilization and Hybridization of DNA on Poly-2,6-pyridinedicarboxylic Acid Film Modified by Nanogold and Interaction with 2-Amininophenoxazine-3-one

在聚2,6-吡啶二甲酸(PDC)膜修饰的玻碳电极上采用电沉积和浸泡结合法制备成纳米金修饰电极(NG/PDC/GCE)。将单链DNA(ssDNA)固定在NG/PDC/GCE电极上制得DNA电化学传感器。采用微分脉冲伏安法(DPV)和交流阻抗谱技术对DNA的固定和杂交进行了表征。实验表明,纳米金修饰于PDC膜上可大大提高DNA探针的固定量。同时采用紫外-可见光谱法研究了在Tris-HCl(pH 6．8)缓冲溶液中3-氨基酚噁嗪(AP)与双链DNA(dsDNA)的相互作用,进而采用交流阻抗谱技术对固定在NG/PDC/ GCE电极上的dsDNA与AP的相互作用进行了表征。结果表明,固定于纳米金土的DNA结构并未改变,仍能与小分子相互作用。

The poly-2,6-pyridinedicarboxylic acid film was tabricated by electro-polymerizing 2,6-pyridinedicarboxylic acid on the glassy carbon electrode（GCE）. The gold nanoparticles（NG）were modified on the PDC/GCE to prepare NG/PDC/GCE electrode via the combined method of electrodeposition and immersing adsorption of NG, and then ssDNA was immobilized on the NG/PDC/GCE electrode by the interaction of NG to DNA. The immobilization of NG, the immobilization and hybridization of DNA were characterized, respectively, by the differential pulse voltammetry（DPV） and electrochemical impedance spectroscopy（EIS）. EIS was used to the indicator-free detection of the target DNA. The NG modified on the PDC enhanced dramatically the immobilization amount of the DNA. Additionally, the interaction between dsDNA immobilized on the NG/PDC/GCE electrode and 2-amininophenoxazine-3-one was also investigated.