基于碳纳米管组装电化学传感器测定金丝桃苷的含量

目的:采用单壁碳纳米管(SWCNTs)修饰玻碳电极(GCE),制作电化学传感器,研究金丝桃苷在传感器表面的电化学行为,建立一种简单的、高灵敏的金丝桃苷的电化学检测新方法。方法:将羧基化SWCNTs滴在GCE表面,采用循环伏安法(CV)研究了金丝桃苷在传感器表面的电化学行为,并对测量条件进行了优化。结果:和裸GCE电极相比较,金丝桃苷在GCE/SWCNTs电极表面的氧化峰电流和还原峰电流均急剧增加,氧化峰电流和还原峰电流与扫描速度的平方根成正比,说明金丝桃苷在修饰电极表面的反应是受扩散控制的过程。在缓冲液的pH为6.0、碳纳米管的用量为10 μL、检测电位为0.34 V的优化条件下时,金丝桃苷浓度在3.0×10^-9~1.0×10^-7范围内与氧化电流呈现良好的线性关系,检出限为2.41×10^-9 mol/L(S/N=3)。结论:该方法灵敏度高,简单易行,具有较好的重现性及稳定性,可用于金丝桃苷的检测。

Determination of Hyperoside Based on a Electrochemical Sensor Assembled with Carbon Nanotubes

Objective:A simple and highly sensitive electrochemical sensor for hyperoside was developed based on a glassy carbon electrode(GCE)modified with carboxylic group-functionalized single-walled carbon nanotubes(SWCNTs)and the electrochemical behavior of hyperoside on the surface of the sensor was studied. Methods:The electrochemical behavior of hyperoside on the surface of the sensor was investigated by cyclic voltammetry(CV). Results:The oxidation peak current and reduction peak current of hyperoside on modified electrode greatly increased compared with bare GCE. Under the optimum conditions:pH of buffer solution was 6.0,the amount of carbon nanotubes was 10 μL and the detection potential was 0.34 V,the oxidation current was linear over a range from 3.0×10-9 to 1.0×10-7 mol/L with a detection limit of 2.41×10-9 mol/L. Conclusion:The sensor had high sensitivity,good reproducibility and stability,and could be used for the detection of hyperoside.