金电极自组装基因分子膜的制备及电化学检测

Preparation and electrochemical determination of gold electrode modified with thiolated capture probe through self-assembling

采用分子自组装技术制备巯基修饰的基因分子膜修饰金电极,用于竞争式杂交检测黄孢原毛平革菌木素过氧化物酶编码基因。通过差分脉冲伏安法、循环伏安法、交流阻抗法和电流—时间曲线法优化自组装时间和信号探针的最佳响应浓度,研究目标基因的线性检测范围和再生性能。结果表明:修饰金电极最优自组装时间为15 h,信号探针的最佳响应浓度为0.51×10-6 mol/L,目标基因的线性检测范围为7.51×10-12-1.05×10-9 mol/L,检测下限为7.51×10-13 mol/L。该修饰电极具有良好的再生性能。

A gold electrode with thiolated capture probe through self-assembling based on the competitive hybridization for detection of target sequence of lignin peroxidase （lip） gene of Phanerochaete chrysosporium was developed. Following hybridizations with competitively hybridized with the target nucleic acid and biotinylated response probe, streptavidin-horseradish peroxidase （HRP） conjugate was applied to the electrode. The electrochemical behavior was analyzed by cyclic voltammetry, electrochemical impedance spectroscopy, current--time curve and differential pulse voltammetry. The results show that the best time for self-assembling is 15 h, and the optimum concentration of response probe is 0.51×10^-6 mol/L. A good linear correlation between the current and the concentration of the target nucleic acid concentration is found in the concentration range from 7.51×10^-12 mol/L to 1.05×10^-9 mol/L. The detection limit is 7.51×10^-13 mol/L. The modified electrode exhibits high sensitivity, precision, stability and reproducibility.