肌红蛋白-壳聚糖-金胶纳米复合薄膜修饰电极的电化学性质

Electrochemical Property of Myoglobin-chitosan-colloid Gold Film Modified Glass Carbon Electrode

在pH=5.4的HAc-NaAc缓冲溶液中,肌红蛋白-壳聚糖-金胶薄膜修饰电极在-0.20 V(vs.Ag/AgC l)处有一对准可逆的氧化还原峰,为Mb血红素辅基Fe(Ⅲ)/Fe(Ⅱ)电对的特征峰.在壳聚糖-金胶纳米复合薄膜的微环境中,肌红蛋白与玻碳电极之间的电子传递明显加快.考察了扫速、溶液pH值及支持电解质浓度等因素对肌红蛋白电子传递的影响.紫外光谱结果表明,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-金胶纳米复合薄膜修饰电极还可用于溶解氧的催化还原.

Myoglobin（Mb）-chitosan-colloidal gold films were made by casting a solution of Mb, chitosan and colloidal gold on glass carbon electrodes. Mb incorporated in chitosan-colloidal gold films gave a pair of. stable, well-defined, and quasi-reversible cyclic vohammetric 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 heine Fe（Ⅱ ）/Fe（ Ⅲ ） redox couple. The effects of scan rate, pH and concentration of buffer solutions on the electrochemical behavior of Mb were studied in detail. Position of the Sorer absorbance band suggests that Mb in chitosan- colloidal gold kept its secondary structure similar to the native states. Oxygen was catalytically reduced by Mb in chitosan-colloidal gold films.