Designing a Hydrogen Peroxide Biosensor Using Catalase and Modified Electrode with Magnesium Oxide Nanoparticles

Abstract

In this study a combination of biology, electrochemistry and nanotechnology was used in designing a biosensor capable of detecting hydrogen peroxide (H2O2) using a modified carbon paste electrode (CPE) with magnesium oxide nanoparticles (MgO NPs) and catalase (CAT) enzyme. Synthesized MgO NPs were studied by Ultraviolet-Visible Spectroscopy (UV-VIS), X-Ray Diffraction (XRD), and Transmission Electron Microscope (TEM). All electrochemical studies were conducted using Cyclic Voltammetry (CV). Results revealed that the CAT/MgO NPs/CPE complex produced a pair of well-defined redox peaks with formal potential E-0 = 100 +/- 2. The existence of Fe ((III/II)) structure in CAT molecule was an important factor that allowed the enzyme to participate in iron (Fe ((III/II))) oxidation-reduction reactions; and these reactions that made it possible to design a biosensor for detecting H2O2. The designed biosensor was able to detect H2O2 in the range of 50-190 mu M. also designed biosensor has a high degree of stability and retained 92% of its original activity after a given duration.