色氨酸在多壁碳纳米管-Nafion修饰玻碳电极上的电化学行为及测定

采用滴涂法制备了多壁碳纳米管-Nafion修饰玻碳电极(MWCNTs-Nafion/GCE),基于此修饰电极,建立了发酵液中色氨酸的电化学检测方法。结果表明:在pH 4.0的磷酸盐缓冲溶液中,色氨酸在MWCNTs-Nafion/GCE电极上有良好的响应,氧化峰电势为1.01 V,在5×10-7-2×10-4mol/L范围内,色氨酸氧化峰电流与其浓度呈良好的线性关系,线性方程为:Ip(10-6 A)=2.432×104 C(mol/L)+3.1452,R2为0.9973,检测限为2.7×10-8mol/L(S/N=3),回收率在98.3%~104.3%之间,相对标准偏差≤3.0%。该方法操作简单、结果稳定、选择性和灵敏度良好。

Electrochemical Behavior and Determination of Tryptophan on Multiwalled Carbon Nanotubes-Nafion Modified Glass Carbon Electrode

A multiwalled carbon nanotubes-Nafion modified glass carbon electrode （MWCNTs-Nafion/GCE） was developed by drop coating method. Based on the modified electrode, a novel electrochemical determination method of tryptophan in fermented liquids was established. The result shows that the MWCNTs-Nafion/GCE electrode exhibits good electrocatalytic activity to tryptophan. With pH 4.0 phosphate buffer solution as supporting electrolyte, at 1.01 V, the oxidation peak currents of tryptophan are in good proportion to the concentrations of tryptophan. The corresponding linear equation is Ip（10-6 A）=2.432× 104 C （mol/L）＋3.1452, R2=0.9973, the linear range of tryptophan concentration is from 5 ×10-7 to 2 × 104 mol/L, the detection limit is 2.7×10-8 mol/L （S/N=3）. This method can be successfully applied to the detection of tryptophan in fermented liquids, the recovery is within 98.3 %-1043 %, RSD≤ 3.0 %. The selectivity and sensitivity of this method are satisfactory, the operation is facile and the results are stable.