A novel application of iron oxide nanoparticles for detection of hydrogen peroxide in acid rain

Determining the concentration of hydrogen peroxide (H2O2) is of great importance in food, pharmaceutical, environmental and clinical analyses. Horseradish peroxidase (HRP), an enzyme specifically catalyzing the oxidative reaction of H2O2 to develop color reaction, has been widely used for measuring H2O2 concentration. However, owing to the instability and high cost of this enzyme, discovering efficient mimics of peroxidase has been important to conquer these disadvantages of protein catalyst. Recently we have found that Fe3O4 magnetic nanoparticles (Fe3O4 MNPs) possess intrinsic peroxidase-like activity, which can catalyze oxidation of various peroxidase substrates in the presence of H2O2. Based on this finding, we developed a spectrometric method using Fe3O4 MNPs as a catalyst to determine H2O2 in rainwater. Our data show that the Fe3O4 MNPs are efficient catalysts to determine H2O2 in rainwater. Compared to HRP, the Fe3O4 MNPs are reusable and economical and these characteristics make the particles a board range of applications in determining H2O2 in the rainwater. (C) 2008 Elsevier B.V. All rights reserved.