导电聚苯胺电极柱识别天冬氨酸对映体的研究

Identification of Aspartic Acid Enantiomers with Conductive Polyaniline Electrode Column

以苯胺为单体,L-天冬氨酸(L-Asp)为模板分子,采用化学氧化法合成了掺杂L-Asp的导电聚苯胺(PAn)。将PAn作为固定相填充到多孔陶瓷管中制备导电PAn电极柱,并以此电极柱作为工作电极。循环伏安图表明PAn电极柱具有良好的电化学活性。在电极柱上施加-0.6 V的还原电位,PAn中掺杂的L-Asp发生脱掺杂,从而在PAn膜上留下了与L-Asp完全匹配的空穴。由于PAn具有掺杂/脱掺杂完全可逆的独特性能,因此对带有分子印迹的PAn电极柱施加0.5 V的正电位后,由于存在强烈的分子印迹作用,L-Asp在电极柱上被富集,而D-天冬氨酸(D-Asp)的富集效果远低于L-Asp,从而实现对Asp对映体的识别。

Conductive polyaniline （PAn） was synthesized by chemical oxidation using L-Asp as template molecules. And a conductive PAn electrode column was fabricated by filling PAn into porous ceramic tube and used as working electrode. The cyclic voltamogramms （CV） showed that the PAn electrode column had good eleetroaetivity. L-Asp anions were excluded from the PAn stationary phase when a constant negative potential of-0.6 V was applied to the electrode column, so cavities complementary to L-Asp anion in shape were left in the PAn stationary phase. The doping/de-doping process of PAn was fully reversible. Based on its unique property of doping/de-doping, when a constant positive potential of 0. 5 V was applied to the electrode column, L-Asp anions were enriched by the stationary phase because of the effect of strong molecular imprinting. However, comparing with that of L-Asp, the enrichment efficiency of D-Asp anions was very poor. Therefore, the identification of Asp enantiomers was realized with the novel electrode column.