Kang T F, Shen G L, Yu R Q
Talanta. 1996 Nov;43(11):2007-13. doi: 10.1016/0039-9140(96)01990-X.
The permselectivity of neurotransmitters such as dopamine, epinephrine, and norepinephrine at overoxidized polypyrrole (OPPY)-film-coated glassy carbon electrodes has been investigated. The chemically-modified electrodes exhibit attractive permselectivity and antifouling properties of rejecting anionic species, e.g. ascorbate, etc. Compared with the response of neurotransmitters at modified electrodes overoxidized in phosphate buffer solution (pH 7.4), higher sensitivity and reversibility response can be obtained at modified electrodes overoxidized in sodium hydroxide solution. The effect of film thickness on the permselective response was tested. Rotating disk electrode experiments were used to determine the apparent diffusion coefficients of several electroactive solutes in the OPPY films. The influence of the hydrophobicity of the organic ions on the permeability within the polymer films was discussed. Dopamine and epinephrine were determined at the 1 x 10(-6)-1 x 10(-4) M level by means of voltammetry after an exposure period of 2 min in 0.1 M phosphate buffer (pH 7.4) with detection limits of 8 x 10(-7) M and 6 x 10(-7) M respectively.
研究了多巴胺、肾上腺素和去甲肾上腺素等神经递质在过氧化聚吡咯（OPPY）膜修饰玻碳电极上的渗透选择性。化学修饰电极表现出吸引人的渗透选择性和抗污性能，可排斥阴离子物种，如抗坏血酸等。与在磷酸盐缓冲溶液（pH 7.4）中过氧化的修饰电极上神经递质的响应相比，在氢氧化钠溶液中过氧化的修饰电极可获得更高的灵敏度和可逆响应。测试了膜厚度对渗透选择性响应的影响。采用旋转圆盘电极实验测定了几种电活性溶质在OPPY膜中的表观扩散系数。讨论了有机离子的疏水性对聚合物膜内渗透性的影响。在0.1 M磷酸盐缓冲液（pH 7.4）中暴露2分钟后，通过伏安法在1×10⁻⁶ - 1×10⁻⁴ M水平测定多巴胺和肾上腺素，检测限分别为8×10⁻⁷ M和6×10⁻⁷ M。
