辣根过氧化物酶在石墨电极上的固定化及其对H_2O_2的响应

Immobilization of horseradish peroxidase on graphite electrode and its response to H_2O_2

基础电极的选择和酶、抗体、DNA等生物活性分子的固定化方法都是影响生物传感器性能的关键因素.以石墨电极(GE)为基础电极,基于辣根过氧化物酶(HRP)对H2O2氧化邻苯二胺(OPD)生成2,3-二氨基吩嗪(DAP)反应体系的高效催化作用,研究了HRP固定化技术.分别利用再生丝素、聚乙二醇、壳聚糖包埋固定HRP,并以HRP修饰GE为指示电极,通过电位法测定H2O2浓度,对不同的固定化方法进行评价.结果表明,利用再生丝素包埋法制备的HRP/GE电极对H2O2具有更好响应性能,其工作曲线斜率为54.97,检测下限为8.82×10-8 mol.dm-3,线性范围为3.53×10-7～8.82×10-4 mol.dm-3.所提出的HRP/GE具有制备简单、成本低廉、响应快、灵敏度高等优良性能,具有较好的应用前景.

Immobilization techniques of bioactive molecules and selectetion of electrode materials are the key procedure for preparation of biosensors.In the present work,horseradish peroxidase（HRP） were immobilized on the graphite electrode（GE） by embedding methods with regenerated silk fibroin,polyethylene glycol and chitosan,respectively.The response performance of HRP modified GEs（HRP/GEs） to H2O2 were studied kinetically in the reaction system of the two substrates H2O2 and o-phenylenediamine.The regenerated silk fibroin embedded HRP/GEs showed a better sensitivity（54.97mV/decede） with a linear range of 3.53×10-7~ 8.82×10-4 mol·dm-3 and the detection limit of 8.82×10-8 mol·dm-3.The resulting HRP/GE showed low cost,simple preparation,rapid response,high sensitivity and good application prospect.