纳米金-Nafion修饰金电极电化学阻抗法测定人端粒DNA

Electrochemical impedance spectroscopic detection of human telomere DNA based on gold nanoparticle nafion modified gold electrode

报道了基于纳米金-Nation修饰金电极检测人端粒DNA的电化学阻抗传感器。将纳米金与Nation混合超声得到纳米金-Nation纳米材料，将此纳米材料滴涂于金电极表面获得纳米金．Nation修饰电极。再将探针人端粒ssDNA滴涂在修饰电极上制备电化学阻抗传感器。利用扫描显微镜对纳米材料的形貌进行了表征。利用循环伏安法和电化学阻抗法对传感器进行了表征及目标人端粒DNA的定量测定。在最优化实验条件下，电化学阻抗传感器响应信号（△Ret）与目标人端粒DNA浓度的对数（1gc）在0．001～1．0nmol/L范围内呈良好线性关系。检出限为3．0pmol／L。对0．5nmol／L的目标人端粒DNA7次平行测定，相对标准偏差RSD为3．5％。

The electrochemical impedance sensor based on the electrode modified with gold nanoparticles （GNPs）-Nation films was developed for the detection of human telomere DNA（DNA）. A new nanocomposite films （GNPs-Nafion） were obtained by mixing gold nanoparticle and nation after ultrasonic dispersion. The GNPs-Nafion nanocomposites were further cast onto a gold electrode to fabricate a novel modified electrode （ GNPs-Nafion/Au）, which was a platform for immobilizing the capturing probe of DNA, as the electrochemical impedance sensor. The electrode modification were characterized by scanning electron microscopy （SEM）. Cyclic vohammetry and electrochemical impedance technology were used to monitor the fabrication process of the electrochemical sensor and quantitative determination of the target DNA hybridization. Under the optimization of experimental conditions, the response signal of the electrochemical impedance sensor （△Rt） was linear with the logarithm of complementary DNA concentrations from 0. 001 to 1.0 nmol/L with a detection limit of 3.0 pmol/L （ SiN = 3 ）. The relative standard deviation obtained was 3.5% with 7 times in parallel determination of 0. 5 nmol/L target DNA. The sensor showed a wide linear range, high sensitivity, no labeling, can be used for the detection of other sequence DNA analysis.