单壁碳纳米管化学修饰电极的制备及其测定鸟嘌呤的研究

Fabrication of Single-wall Carbon Nanotube-Modified Electrode and Its Determination of Guanine

报告了一种制备单壁碳纳米管化学修饰电极的方法,并研究了鸟嘌呤在此修饰电极上的电化学行为.鸟嘌呤在单壁碳纳米管修饰玻碳电极上出现一个灵敏的氧化峰,峰电流位于0.64V(vs.SCE).与裸玻碳电极相比,单壁碳纳米管修饰电极显著提高鸟嘌呤的氧化峰电流.优化了各项测定参数,建立了一种直接测定鸟嘌呤的电分析方法.氧化峰电流与鸟嘌呤的浓度在5×10～8-2 × 10-5mol/L之间有很好的线性关系,开路富集3min,检出限为2×10～8mol/L.该方法检测限低、分析速度快、重现性好、准确可靠.

In this paper, a novel technique to construct single -wall carbon nanotube (SWNT) film coated electrode was described. The electrochemical behavior of guanine at the SWNT - modified glassy carbon electrode (GCE) was investigated. In 0. 1 mol/L phosphate buffer (pH 7. 0) , guanine (G) yields a well - defined and sensitive oxidation peak at the SWNT - film coated GCE. The oxidation peak potential is about 0.64 V vs. SCE. The oxidation peak current enhances significantly at the SWNT - modified GCE in comparison with that at the bare GCE. The experiment parameters such as buffer PH, accumulation time, the amount of SWNT - DHP suspension and scan rate, were optimized. The oxidation peak current is proportional to the concentration of G over the range from 5 × 10 -8 to 2 × 10 -5 mol/L. The detection limit is 2 ×10 ~8 mol/L at 3 min accumulation.