Surface renewable sol-gel composite electrode derived from 3-aminopropyl trimethoxy silane with covalently immobilized thionin.
Surface renewable sol-gel composite electrode derived from 3-aminopropyl trimethoxy silane with covalently immobilized thionin.
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DOI：
10.1016/j.bios.2007.06.003
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发表时间：
2007-12
影响因子：
12.6
通讯作者：
K. Thenmozhi;S. Narayanan
中科院分区：
文献类型：
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作者：
K. Thenmozhi;S. Narayanan
采用溶胶-凝胶技术对水溶性介质硫氨酸进行共价固定化，构建了一种体修饰、无泄漏的复合电极。这种可再生复合电极通过戊二醛交联为硫蛋白提供了稳定的固定基质。在电极组合物中，溶胶-凝胶前驱体3-氨基丙基三甲氧基硅烷作为固定硫离子的宿主，从而防止其泄漏。另外的前体甲基三甲氧基硅烷赋予疏水性并限制修饰电极的润湿部分。在0.2 ~−0.6V的电位范围内，修饰电极的循环伏安特性显示出稳定的氧化还原峰，其形式电位为−0.273V，与固定化硫离子对应。该化学修饰电极在−0.35V的低电位下表现出良好的还原h2o2的电催化活性。改性电极的还原电流在3.44×10−6M ~ 3.07×10−3M范围内呈线性增加，检测限为1.38×10−6M。在计时电流测量过程中，该电极的响应稳定且快速（5s），显示了该电极在流动系统分析中的潜在应用前景。低电位操作（−0.35V）有利于选择性测定H2O2。复合电极在表面结垢时具有明显的抛光优势，制备简单，化学和机械稳定性好，经济且长期稳定性显著（1年以上）。本传感器对h2o2测定的适用性为其他具有生物学意义的分析物的检测提供了一种方法。
Sol–gel technique has been used for the covalent immobilization of the water-soluble mediator, thionin to construct a bulk modified, leak free composite electrode. This renewable composite electrode provides stable immobilization matrix for thionin via glutaraldehyde crosslinking. In the electrode composition the sol–gel precursor 3-aminopropyltrimethoxy silane serves as the host for immobilization of thionin, thereby preventing its leakage. An additional precursor methyl trimethoxy silane endows hydrophobicity and limits the wetting section of the modified electrode. Cyclic voltammetric characterization of the modified electrode in the potential range of 0.2 to −0.6V exhibited stable redox peaks with a formal potential of −0.273V, corresponding to immobilized thionin. This chemically modified electrode exhibits good electrocatalytic activity for the reduction of H2O2at a lower potential of −0.35V. The reduction current of the modified electrode increases linearly in the range of 3.44×10−6M to 3.07×10−3M H2O2with a detection limit of 1.38×10−6M. The stable and quick response (5s) during chronoamperometry shows the potential application of the modified electrode for flow system analysis. The low potential operation (−0.35V) favoured selective determination of H2O2. The composite electrode exhibits distinct advantages of polishing in the event of surface fouling as well as simple preparation, good chemical and mechanical stability, economical and remarkable long-term stability (more than 1 year). The applicability of the present sensor for H2O2determination proposes a method for the detection of other biologically significant analytes.