抗坏血酸在半胱氨酸自组装膜上的电化学行为及应用

The Electrochemistry of Ascorbic Acid on Cysteine Self-Assembled Monolayers and Its Application in Food Analysis

半胱氨酸自组装修饰金修饰电极对抗坏血酸(Vc)具有很高的电催化氧化活性.在pH 2.0的0.1 mol/L缓冲溶液中,可得到一对准可逆的氧化还原峰.电极反应受扩散控制.氧化峰电流与抗坏血酸浓度在5.0×10-6～1.1×10-3 mol/L范围内成线性关系,检测限为1.0×10-6 mol/L.该分析方法应用于果汁中的抗坏血酸分析,结果令人满意.

The cysteine self-assembled monolayers modified electrode show an excellent electrocatlysis response for the ascorbic acid. A pair of well-defined redox peaks was obtained. The electrode reaction is a diffusion-controlled process. The oxidative peak current is proportional to the concentration of ascorbic acid in the range of 5.0 × 10^-6- 1.1 × 10^-3mol/L by voltammetry. The detection limit is down to 1.0 × 10^-6 moll L. The modified electrode can be used for the determination of ascorbic acid in the juice with satisfactory results.