【摘要】 采用不同电化学方法对神经递质多巴胺（ＤＡ）在蒙脱土修饰电极上的行为进行了研究，结果发现，蒙脱土修饰膜对ＤＡ有明显的富集作用。在ｐＨ ７．４时，ＤＡ强烈地富集在蒙脱土膜内，并显示完好的伏安响应；而抗坏血酸（ＡＡ）和ＤＡ的代谢产物３，４－二羟基苯乙酸（ＤＯＰＡＣ）则无任何响应。采用计时库仑法测定了 ＤＡ在蒙脱土膜内的表观扩散系数为 ２．３ ×１０－９ｃｍ２／ｓ，并计算了异相电子转移速率常数为 ２．７×１０－５ｃｍ／ｓ。在选定的条件下，ＤＡ在蒙脱土膜电极上的溶出电流与浓度在８．０×１０－６～２．２×１０－５ｍｏｌ／Ｌ范围内具有线性关系，表明该电极可用于ＤＡ的溶出伏安测定。更多还原

【Abstract】 The electrochemical behavior of dopamine on the montmorillonite-modified elec- trode was studied by cyclic voltammetry. The cationic dopamine was strongly accumulated on the modified electrode at pH= 7. 4, while anionic ascorbic acid and 3, 4-dihydroxyphenyl acetic acid were not. The linear relationship between the stripping current and concentration for DA existed in the range of 8. 0×10-6 - 2. 2 × 10-5 mol/L. The apparent diffusion coeffi- cient of DA in the film determined by chronocoulometry was 2. 3 × 10-9 cm2/s. The rate con- stant of the heterogeneous electron transfer was calculated to be 2. 7 × 10-5 cm/s.更多还原