Electrochemical Sensing of DNA Immobilization and Hybridization Based on Carbon Nanotubes/Nano Zinc Oxide/Chitosan Composite Film and Its Application
A novel and sensitive electrochemical DNA biosensor based on ZnO nanoparticles and multi-walled carbon nanotubes (MWNTs) for DNA immobilization and enhanced hybridization detection is described. The MWNTs/nano ZnO/chitosan-modified glassy carbon electrode (GCE) was fabricated and oligonucleotides were immobilized on the modified electrode. The hybridization reaction on the electrode was monitored by differential pulse voltammetry (DPV) using methylene blue (MB) as an indicator. As compared with previous DNA sensors with oligonucleotides directly incorporated on carbon electrodes, this carbon nanotube-based assay with its large surface area and good charge-transport characteristics increased DNA attachment quantity and complementary DNA detection sensitivity. The difference of the cathodic peak currents of MB in differential pulse voltammetry between before and after the hybridization of the probe DNA was used as the signal for the detection of the target DNA. The sequence-specific DNA of PAT gene in the transgenic plants was detected with a detection range from 1.0×10-11 mol/L to 1.0×10-6 mol/L, and a detection limit of 2.8×10-12 mol/L (3σ). This is the first application of carbon nanotubes combined with nano ZnO to the fabrication of an electrochemical DNA biosensor with a favorable performance for the rapid detection of specific hybridization.
Multi-walled carbon nanotubes ZnO nanoparticles Chitosan DNA sensor Methylene blue
张伟 杨涛 焦奎 李智
青岛科技大学化学与分子工程学院,山东青岛 266042
国际会议
成都
英文
2007-11-19（万方平台首次上网日期，不代表论文的发表时间）