Design a biosensor by using Modified glassy carbon electrode With HRP Enzyme and Zro2 Nanoparticles for Detect of H2O2 was studied. The heme group of HRP Enzyme played an important role in reduction (Fe2+) an oxidation (Fe3+) state in our electrochemical experiments. The phase characterization of ZrO2 nanoparticles was performed by X-ray diffraction (XRD) using a D/Max-RA diffractometer with CuKα radiation. The absorbance properties of prepared nanoparticles were measured and recorded by using a TU-1901 double-beam UV-visible spectrophotometer. The morphologies and particle sizes of the samples were characterized by JEM-200CX transmission electron microscopy (TEM). The formal potential (E0) for the HRP redox reaction on the HRP / ZrO2 NPs/ GCE was equal to +0.49. This experiment has introduced a new biosensor for determination of H2O2 in the range of 50 to 400 μM
