We used of Nanoscience, biology and electrochemistry in designing a new hydrogen peroxide biosensor by using modified Carbon Paste Electrode with catalase enzyme and Mn2O3 Nanoparticles. Cyclic voltammetry method as a general method in electrochemical studies was performed using an Autolab potentiostat. A conventional threeelectrode cell was employed throughout the experiments. The produced Mn2O3 Nanoparticles was characterized by XRD, UV-visible, SEM and TEM analysis. The direct electrochemistry behavior of CAT / Mn2O3 Nps/ CPE was studied and a pair of well-defined redox peaks was observed at the CAT / Mn2O3 Nps/ CPE in a 0.1 mol L−1 phosphate buffer solution (PBS) of pH 7.0 at a scan rate of 100mVs−1 compared to the Mn2O3 Nps/ CPE. Its anodic peak potential and cathodic peak potential were located at −150mV and −200mV (vs. SCE), respectively. The formal potential (Eo) of Catalase, estimated as the midpoint of reduction and oxidation potentials, was - (175 ± 2) mV. The presented experiment has introduced a new biosensor for the sensitive determination of H2O2 in the solution in the range of 15-135 μM.
