环芬化合物膜修饰电极对8-氮鸟嘌呤的电催化研究

用循环伏安法在石墨碳电极上制备环芳化合物膜修饰电极 ,研究该修饰电极的性质及电催化性能。该电极在pH <9的PBS溶液中能稳定存在 ,膜的循环伏安图上有两对氧化还原峰 ,峰电位随pH值的增大而负移。在pH =7.9的PBS中 ,氧化峰电流与扫速平方根υ1/ 2 在 10 0～ 5 0 0mV·S-1范围内成正比 ,表明电荷在膜中的传递受扩散影响。在pH =7.9的弱碱性溶液中该修饰电极对 8-氮鸟嘌呤有明显的电催化作用 ,且有一质子和一电子参与反应。在 1.0× 10 -4～1.0× 10 -2 mol·L-1范围内峰电流与 8-氮鸟嘌呤浓度呈线性关系。

The Studies on a Novel Cyclophane Modified Graphite Electrode and Electrocatalytic Oxidation of 8 - Azaguanine

The graphite electrode chemically modified with a novel cyclophane (abbreviated as(bis edtapdn)H 4)by cyclic voltammetry was prepared.The cyclic voltammograms of the film electrode in PBS(pH=7.9) exhibited two pairs of redox waves,E p.a1 =0.425?V,E p.c1 =0.275?V,E p.a2 =0.775?V,E p.c2 =0.425?V. However,the peak potentials of these redox wavse shifted positively with pH decline,and the current increased in line with the square root of scan rates.The (bis edtapdn)H 4film electrode showed stable and quasi reversible electrochemical behavior in PBS (pH<9)and a good catalytic ability to the 8 azaguanine.The catalytic current peak was increased much more and the peak potential was shifted negatively 150mV than the bare graphite electrode.