复合高分子膜修饰电极直接测定大脑内源性神经递质

Determination of the Neurotransmitter in the Brain Using Composite Polymer Microelectrodes

采用阳离子交换剂Ｎａｆｉｏｎ和醋酸纤维素复合修饰的碳纤维电极具有电荷选择性和尺寸选择性．对复杂样品具有独特的选择性和抗干扰性．在动物活体伏安分析中，该复合修饰电极成功地抑制了神经递质代谢产物、抗坏血酸和尿酸等电化学活性物质在电极表面的反应，直接检测了脑内神经递质多巴胺的氧化电流．该电极采用静电浸渍法多次涂布，使电极的复合膜牢固，并具有很好的分析性能．同时，对复合修饰电极的作用机理进行了探讨．

A composite polymer carbon fiber electrode modified with Nafion and cellulose acetate is described.The incorporation of ion exchanging polymer to the cellulose acetate domain allows the binding of counterionic reactants, while maintaining the size exclusion discriminative properties of cellulose acetate.In vivo voltammetry,the modified microelectrode inhabits the oxidation of some neurotransmitter metabolites and electroactive compounds,such as DOPAC, 5-HIAA, HVA, AA and UA;and successfully detects the oxidative current of neurotransmitter DA.