苯胺红T与辣根过氧化氢酶共固定无试剂过氧化氢传感器的研制

Reagentless Hydrogen Peroxide Biosensor Based on the Coimmobilization of Safranine T and Horseradish Peroxidase by Their Cross-Linking Effect

将辣根过氧化氢酶(HRP)与氧化还原型染料苯胺红T(ST)用戊二醛交联共固定在玻碳电极的表面,制得了无试剂过氧化氢传感器。该传感器在水溶液中显示了很好的电化学活性。苯胺红的表现覆盖度为9.22×10-11mol/cm2,苯胺红与玻碳电极之间的异相电子转移速率常数为0.066 s-1,研究了响应时间、检测限、检测电位、溶液pH和测定温度等因素对传感器性能的影响。在优化条件下,该传感器对过氧化氢的最低检测限为1.0×l0-7mol/L。多巴胺、抗坏血酸和尿酸等不干扰过氧化氢的测定。而且,该酶电极显示了较好的稳定性。

A novel reagentless H2O2 sensor, based on the coimmobilization of horseradish peroxide （HRP） and the redox dye safranine T （ST） by their cross-linking with glutaradehyde on the surface of a glassy carbon electrode, was fabricated. The resulting modified electrode exhibited good electrochemical activity in aqueous solution, and the electron transfer rate constant between the derivative safranine T and glassy car- bon electrode was about 0.066s^-1 （calculated from laviron＇s method）. The apparent surface coverage of ST was about 9.22×10^-11mol/cm^2. It was found ST could mediate the electron transfer of HRP with the electrode substrate. Performance and characteristics of the biosensor were evaluated with respect to response time, detection limit, applied potential, pH and temperature. The results indicated that this biosensor is of high sensitivity to hydrogen peroxide with a low detection limit down to 1.0×10.7mol/L. Moreover, dopamine, ascorbic acid and uric acid did not interfere with the determination of H2O2. Meanwhile, this enzyme electrode also showed good stability and reproducibility for long-term use.