Recombinant horseradish peroxidase - and cytochrome c-based two-electrode system for detection of superoxide radicals
- 作者：Shipovskov ; Stepan ; Ferapontova ; Elena E. ; Gazaryan ; Irina ; Ruzgas ; Tautgirdas
- 关键词：Superoxide radical ; Hydrogen peroxide ; Cytochrome c ; Recombinant horseradish peroxidase ; Bi-electrode system
- 刊名：Bioelectrochemistry
- 出版年：2004
- 期刊代码：7_15675394
- 类别：ch
- 出版时间：June, 2004
- 卷：63
- 期：1-2
- 页码：277-280
- 文件大小：126 K
摘要
The reliable detection of a superoxide anion radical O2
− is complicated by its spontaneous dismutation reaction to H2O2 at acidic pHs. To simultaneously detect both O2− and H2O2 produced in the course of its spontaneous dismutation, an electrochemical two-electrode system based on cytochrome c (cyt c) and recombinant horseradish peroxidase (rHRP) was applied. Therewith, a limited applicability of the cyt c system for the reliable monitoring of O2− in acidic and neutral solutions was shown. It was demonstrated that both the reaction of O2− dismutation to H2O2 and the reaction between the formed H2O2 and O2− chemically decrease the amount of the initially present O2−, decreasing the sensitivity and reliability of the electrochemical detection at acidic pH. However, by appropriately varying solution pH, the concentration of O2− initially injected in the system can be estimated from the analysis of calibration curves for H2O2 obtained with highly sensitive rHRP-modified electrode system at pH 6.0 and 7.0.
− is complicated by its spontaneous dismutation reaction to H2O2 at acidic pHs. To simultaneously detect both O2− and H2O2 produced in the course of its spontaneous dismutation, an electrochemical two-electrode system based on cytochrome c (cyt c) and recombinant horseradish peroxidase (rHRP) was applied. Therewith, a limited applicability of the cyt c system for the reliable monitoring of O2− in acidic and neutral solutions was shown. It was demonstrated that both the reaction of O2− dismutation to H2O2 and the reaction between the formed H2O2 and O2− chemically decrease the amount of the initially present O2−, decreasing the sensitivity and reliability of the electrochemical detection at acidic pH. However, by appropriately varying solution pH, the concentration of O2− initially injected in the system can be estimated from the analysis of calibration curves for H2O2 obtained with highly sensitive rHRP-modified electrode system at pH 6.0 and 7.0.