壳聚糖/DNA/血红蛋白/多壁碳纳米管复合膜修饰玻碳电极的制备及其电化学行为的研究

Preparation of Modified GCE by Composite Film of CTS/DNA/Hb/ MWCNTs and Study on Its Electrochemical Behavior

将多壁碳纳米管(MWCNTs)分散在壳聚糖(CTS)中并滴涂在玻碳电极表面,烘干后依次滴加血红蛋白(Hb)、DNA及CTS溶液.制成了壳聚糖/DNA/血红蛋白/多壁碳纳米管复合膜修饰的GCE(简示为CTS/DNA/Hb/MWCNTs/GCE)。采用方波伏安法及循环伏安法研究了膜内DNA的电化学行为。结果表明:在pH 5.8的磷酸盐缓冲溶液中,复合膜内的DNA在电极上于0.46 V(vs.SCE)处有一个明显的氧化峰,DNA氧化峰电流与其质量在1.0～5.0μg范围内呈线性关系,检出限(3S/N)为0.5μg。

Multi-walled carbon nanotubes （MWCNTs） were dispersed in chitosan （CTS） and dropped on the surface of glassy carbon electrode （GCE）, after drying solutions of hemoglobin （Hb）, DNA and CTS were successively dropped on the above electrode, to form the composite film modified CR3E or named abbreviately as CTS/DNA/Hb/MWCNTs/GCE. The electrochemical property of the modified electrode was studied by square wave voltammetry and cyclic voltammetry. It was found that DNA in film showed an obvious oxidative peak at the potential of 0. 46 V （vs. SCE） in phosphate buffer solution of pH 5. 8. Linear relationship between values of oxidative peak current and mass of DNA in the composite film was obtained in the range of 1.0--5.0 μg. Value of detection limit （3S/N） was found 0. 5 μg.