细胞色素c在马铃薯膳食纤维修饰电极上的直接电化学行为

Direct Electrochemistry of Cytochrome c at Potato Dietary Fiber Modified Electrode

用水蒸汽爆破和氧化法对马铃薯废渣（PR）进行处理制备马铃薯膳食纤维（PDF），并用红外光谱法、扫描电镜等方法对膳食纤维进行表征。结果表明，马铃薯渣中的半乳聚糖在蒸汽爆破下由长链断成短链，且由原来的块状变成片状、无规则的空间网层结构，断链的半乳糖醛基在氧化作用下生成羧基 所得到的PDF具有比表面积大、吸附位点多等特点。将马铃薯膳食纤维与聚乙烯醇（PVA）制备成水凝胶修饰到玻碳电极表面，研究细胞色素c（Cyt c）在该电极上的直接电化学，探讨了马铃薯膳食纤维与Cyt c间的相互作用，构建了新型过氧化氢生物传感器。用计时电流法测定过氧化氢的线性范围为8.0×10^-6～2.4×10^-4mol/L，检出限为4.0×10^-6mol/L。

Potato dietary fiber （PDF） was prepared from the waste residue of potato by steam explosion and oxidation. The structure and morphology of potato dietary fiber were investigated by IR and SEM. After a series of physical and chemical treatments, the long chains of galactan in potato residue turned into short chains,the original blocks became irregular platelike net-bedded structure, and the aldehyde groups of galactose changed into carboxyl groups. PDF had the characteristics of larger specific surface area and high thermal stability. A novel electrochemical sensor was developed by modifying the surface of glassy carbon electrode with PDF and polyvinyl alcohol. The direct electron transfer of cytochrome c immobilized on this modified electrode was studied. The interactions between cytochrome c and PDF were investigated by UVvis and electrochemical methods. A new biosensor of hydrogen peroxide with a linear calibration range of 8.0×10^-6～2.4×10^-4 mol/L and a detection limit of 4.0×10^-6 mol/L was constructed.