基于有机-无机杂化材料的硝酸还原酶电极的研究

在制备由聚乙烯醇和二氧化硅溶胶凝胶掺杂而成的有机-无机杂化材料的基础上，将硝酸还原酶用此杂化材料包埋固定在金盘电极上，利用甲基紫精为电子媒介体，制得高性能的安培型硝酸还原酶电极。此酶电极可以在-0.68 V（SCE）下对硝酸根进行测定，最适pH值为7.0，载酶量为7.2 mU。在选定的工作条件下，此酶电极的灵敏度和线性范围分别为2.53 nA/(μmol·L^-1)和0.01～0.36 mmol/L ，平均响应时间为12.1 s左右。

Amperometric Nitrate Reductase Biosensors Based on Organic-inorganic Hybrid Material

An organic-inorganic hybrid material based on sol-gel derived SiO₂ and PVA has been obtained. Nitrate reductase is immobilized with this hybrid material on gold electrode surface and an amperometric nitrate reductase biosensor of high performance has been fabricated. The nitrate reduction reaction is driven by the enzyme and methyl viologen which is used as the electron transfer mediator. The developed sensor is applied to detect nitrate with operating potential of -0.68V (vs. SCE). Optimum pH is 7.0 and enzymes loading are 7.2 mU. Under selective conditions the biosensor shows sensitivity of 2.53 nA/(μmol·L^-1) and a linear range of 0.01～0.36 mmol/L. The average response time is 12.1 s.