检测牛奶中过氧化氢的电化学酶传感器的研制

构建一种基于聚硫堇的丝网印刷电化学酶传感器，用于牛奶中过氧化氢的检测。将硫堇电聚合在丝网印刷碳电极上，用壳聚糖二氧化硅溶胶凝胶包埋辣根过氧化酶并固定于聚硫堇电极表面，制成新型过氧化氢生物传感器。结果显示：在牛奶标液中加入不同浓度的过氧化氢后，该酶传感器的响应电流与过氧化氢浓度在3×10-5～1.5×10-3mol/L范围内呈良好的线性关系(R＝0.9964)，最低检出限为1.675×10-5mol/L。该传感器应用于牛奶中过氧化氢的检测与国标碘量法基本一致，其加样回收率范围为85.6%～89.4%。该酶传感器灵敏快速(15min)、制作方便、样品处理简单，有望用于牛奶中过氧化氢的快速检测。

Fabrication of Enzyme Biosensor for Hydrogen Peroxide Detection in Milk

An electrochemical enzyme biosensor was developed to determine hydrogen peroxide in milk. Thionine was electropolymerized on screen-printed electrode, followed by coating the electrode surface with horseradish peroxidase embedded in chitosan-silica sol-gel. The results showed that the response current of the sensor was linearly related to the concentration of hydrogen peroxide in milk samples over the range of 3×10-5 to 1.5×10-3 mol /L with a detection limit of 1.675 ×10-5 mol /L. Recovery rates ranging from 85.6% to 89.4% were obtained in the determination of real samples using the sensor and the results were agreed with those obtained from the Chinese national standard by iodometry method. This method is sensitive, fast and convenient and has potential for applications in the determination of hydrogen peroxide in milk.