肌红蛋白-壳聚糖-金胶纳米复合修饰电极的电催化

Electrocatalysis of Myoglobin-chitosan-Au Colloid Film Modified Glass Carbon Electrode

在pH 5.4的HAc-NaAc缓冲溶液中,肌红蛋白-壳聚糖-金胶薄膜修饰电极(Mb-Ch itosan-Au colloid/GCE)于-0.20 V(vs.Ag/AgC l)处有一对准可逆的氧化还原峰,即Mb血红素辅基Fe(Ⅲ)/Fe(Ⅱ)电对的特征峰.本实验条件下,肌红蛋白与玻碳电极之间的电子传递明显加快,并考察了扫速、溶液pH及支持电解质浓度等因素对肌红蛋白电子传递的影响.紫外光谱图表明:肌红蛋白在壳聚糖-金胶溶液中依然保持其原始构象.该肌红蛋白-壳聚糖-金胶纳米修饰电极还能电催化溶解氧的还原.

The cyclic vohammgram of Mb/AAO/Au Colloid/GCE shows a pair of well-defined and nearly reversible peaks at about - 0.20 V （ vs. Ag/AgCl） in 0.1 mol/L NaAc-HAc buffer （ pH = 5.4） , being the characteristic peaks of the Mb heme Fe（ Ⅲ） / Fe（ Ⅱ）redox couples. The electron transfer between Mb and the electrode was greatly enhanced under present testing conditions. The effects of scan rate, pH and buffers concentration on the electrochemical behaviors of Mb were studied in detail. Position of the Soret absorbance band suggested that Mb in chitosan-coltoidal gold hept its secondary structure similar to the native states. Oxygen was catalytically reduced by Mb in chitosan-colloidal gold films.