Reactive oxygen species (ROS) such as the superoxide anion radical (O2-•) play an essential role on normal cellular growth and homeostasis. However, excess ROS generated by perturbing O2-• homeostasis under various conditions of oxidative stress induce high radical toxicity, resulting in many diseases such as a cancer, brain and mitocondrial infarction, and inflammation. Therefore, quantitative measurement of O2 1• in vivo is important for clarifying their relationship under various conditions. However, in most cases, the biological significance and mechanism of the O2 1• generation are not well understood yet. We have developed a O21• sensor composed of a thin film of N-methylimidazole-coordinated iron meso-tetra (3-thienyl) porphyrin ((Im)2FeT3ThP) for the electrochemical detection of O2-•. The microsensor displayed high selectivity and activity for the oxidation of O2 -• and showed a linear relationship between electric current and O2-• concentration. In this study, we have designed and synthesized a novel hexa-coordinated iron (III) porphyrin compound, which is more stable than the meso-tetra (3-thienyl) porphyrin coordinating imidazoles. This compound was electropolymerized onto the electrode and used as a O2 -• sensor. The redox potential of the electrode suggests that the molecular structure in the electropolymerized film is maintained. This novel modified electrode displayed a high activity for the oxidation of O2-• even in the presence of H2O2 and showed a linear relationship between the electric current and O2-• concentration.
ASJC Scopus subject areas