多壁碳纳米管/纳米Ag-TiO_2膜DNA电化学生物传感器  

Electrochemical Deoxyribonucleic Acid Biosensor Based on Multi-walled Carbon Nanotubes/Ag-TiO_2 Composite Film for Label-free Phosphinothricin Acetyltransferase Gene Detection by Electrochemical Impedance Spectroscopy

作　　者：周娜[1] 杨涛[1] 焦奎[1] 宋彩霞[1] 

机构地区：[1]青岛科技大学化学与分子工程学院,青岛266042

出　　处：《分析化学》2010年第3期301-306,共6页Chinese Journal of Analytical Chemistry

基　　金：国家自然科学基金(Nos.20635020;20805025;20975057)项目;教育部博士点基金(No.20060426001);青岛市基础研究项目(No.09-1-3-25-jch)资助

摘　　要：基于多壁碳纳米管/纳米Ag-TiO2复合膜制备了高灵敏度的DNA电化学生物传感器。将Ag-TiO2复合物与适量分散于N,N-二甲基甲酰胺中的多壁碳纳米管(MWNT)相混合,形成均匀稳定的混合溶液,将其滴涂于裸碳糊电极表面,制得MWNT/Ag-TiO2修饰碳糊电极。碳纳米管大的比表面积和良好的电子传递性能与Ag-TiO2纳米复合物良好的生物相容性和对DNA极好的吸附能力的协同作用,显著提高了DNA探针的固载和DNA杂交的检测灵敏度。应用循环伏安法和电化学交流阻抗谱分别对传感膜的制备和DNA的固定与杂交进行了表征。以电化学交流阻抗谱法对转基因植物外源草丁膦乙酰转移酶基因片段进行了检测,线性范围为1.0×10-11～1.0×10-6mol/L,检出限为3.12×10-12mol/L。A highly sensitive electrochemical deoxyribonucleic acid（ DNA） biosensor based on multi-walled carbon nanotubes（ MWNT） /Ag-TiO2 composite film was developed. The solution containing Ag-TiO2-MWNT composite was casted on the carbon paste electrode surface to form a robust film,which combine the advantages of the good biocompatibility of Ag-TiO2 naocomposite and the fine conductivity,as well as the large active surface area of carbon nanotubes. The composite could greatly improve the immobilization capacity of the probe DNA. The morphologies and electrochemistry of the nanocomposite film were investigated by scanning electron microscopy and electrochemical techniques including electrochemical impedance spectroscopy and cyclic voltammetry,respectively. DNA hybridization events were monitored by a label-free method of electrochemical impedance spectroscopy. This label-free electrochemical impedance DNA biosensor showed high sensitivity and selectivity for phosphinothricin acetyltransferase gene sequence assay. The multicomponents films also displayed a high stability during repeated regeneration and hybridization process.

关 键 词：DNA电化学传感器 多壁碳纳米管 Ag/TiO2复合物 草丁膦乙酰转移酶基因 交流阻抗谱 

分 类 号：TP212.3[自动化与计算机技术—检测技术与自动化装置]