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化学学报
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化学学报 ›› 2011, Vol. 69 ›› Issue (16): 1903-1908. 上一篇    下一篇

研究论文

细胞色素c在植物凝胶-离子液体复合膜修饰电极上的直接电化学

张亚*,1，郑建斌2   

  1. (1榆林学院化学与化工学院 榆林 719000)
    (2西北大学分析科学研究所 西安 710069)
  • 投稿日期:2010-12-27 修回日期:2011-03-21 发布日期:2011-04-20
  • 通讯作者: 张亚 E-mail:zhangya1103@126.com
  • 基金资助:

    陕西省科技厅;陕西省教育厅;榆林市科技局;榆林学院

Direct Electrochemistry of Cytochrome c Immobilized on Geuam Gum-Ionic Liquids Composite Film Modified Electrode

Zhang Ya*,1 Zheng Jianbin2   

  1. (1 Department of Chemistry and Chemical Engineering, Yulin College, Yulin 719000)
    (2 Institute of Analytical Science, Northwest University, Xian 710069)
  • Received:2010-12-27 Revised:2011-03-21 Published:2011-04-20

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1091

被引次数

10

用植物凝胶(GG)和亲水性离子液体(ILs)氯化1-庚基-3-甲基咪唑([HMIM]Cl)制得一种有效的复合膜(GG-ILs). 将细胞色素c (Cyt c)包埋在该复合膜中并修饰于玻碳电极(GCE)表面, 构置了细胞色素c修饰玻碳电极(GG-Cyt c-ILs/GCE). 紫外-可见光谱表明, 复合膜内的Cyt c仍保持其原始构象. 在pH 7.0的磷酸盐缓冲溶液中, GG-Cyt c-ILs/GCE产生了一对峰形良好、几乎对称的氧化还原峰, 说明Cyt c与电极之间发生了直接电子传递, Cyt c在电极表面直接电子转移的速率常数ks为3.87 s－1. Cyt c修饰电极对过氧化氢的还原有电催化作用, 其表观米氏常数Km为0.56 mmol•L–1, 催化电流与过氧化氢浓度在1.0×10－6～2.7×10－4 mol•L－1范围内呈线性关系, 检出限为5.0×10－7 mol•L－1. GG-ILs复合膜可用于构置第三代无试剂的H2O2传感器.

关键词: 细胞色素c, 离子液体, 植物凝胶, 电化学, 电催化

A robust and effective composite film based on geuam gum (GG) and hydrophilic ionic liquid (ILs) 1-heptyl-3-methyl-imidazolium chloride ([HMIM]Cl) was prepared. The composite film can be readily used as an immobilization matrix to entrap cytochrome c (Cyt c). UV-Vis spectroscopy showed that Cyt c retained its native structure in the composite film. A pair of well-defined and quasi-reversible redox peaks of Cyt c was obtained in 0.10 mol•L－1 pH 7.0 phosphate buffer solution (PBS) at the GG-Cyt c-ILs composite film modified glassy carbon electrode (GG-Cyt c-ILs/GCE), indicating the direct electron transfer between Cyt c and the underlying electrode. The electron transfer rate constant (ks) of Cyt c on the electrode surface was 3.87 s－1. The GG-Cyt c-ILs/GCE showed an excellent electrocatalytic activity toward the reduction of H2O2. The catalytic peak current was linear to H2O2 concentration in the range of 1.0×10－6～2.7×10－4 mol•L－1, with a detection limit of 5.0×10－7 mol•L－1. The apparent Michaelis-Menten constant (Km) was estimated to be 0.56 mmol•L－1. Based on the GG-ILs composite film, a third-generation reagentless biosensor could be constructed for the determination of H2O2.

Key words: cytochrome c, ionic liquid, geuam gum, electrochemistry, electrocatalysis