Amperometric detection of hydrogen peroxide at a Prussian Blue-modified FTO electrode

This research focuses on the use of a Prussian Blue (PB)-modified optically transparent electrode for sensing hydrogen peroxide (H2O2). The PB thin films were deposited galvanostatically onto F-doped tin oxide (FTO) glass substrates. Then a reliable and reproducible detection was achieved by exerting a constant bias of −0.2 V (versus Ag/AgCl/saturated KCl) at the PB-modified FTO electrode immersed in an H2O2 solution containing 0.1 M KCl, pH 2. The dynamic range of detection was found to lie between 50 μM and 50 mM, and the sensitivity was ca. 58.1 mA/cm2 M. But it was also observed that the dissolved oxygen interfered the H2O2 sensing. Better sensing results could be obtained if the solution was pre-purged with N2. To sum up, this study possesses the potential to eliminate the use of costly platinum or glassy carbon in a PB-based H2O2 sensor and may provide the basis for optical sensing.