Recombinant Mn Peroxidase from Corn Grain Has an Excellent Electrocatalytic Effect in a Designed Amperometric Biosensor To Detect Hydrogen Peroxide at Low Concentrations

For the first time, we introduce a novel enzymatic biosensor using recombinant plant-produced Mn peroxidase (PPMP) extracted from corn grain to fabricate a facile, fast, and cost-beneficial biosensor for electrochemical detection of hydrogen peroxide (H2O2). The PPMP-modified gold electrode (PPMP/Au) showed excellent amperometric detection for the selective and sensitive enzymatic detection of H2O2. A wide linear range of 0.005–2.5 mM and a lower detection limit (LOD) of 1.3 μM (1.3 × 10–6 mol L–1) were observed. The newly developed biosensor also displayed high sensitivity with a detection limit of 8.2 μM using linear sweep voltammetry (LSV) and 7.0 μM when applying cyclic voltammetry. The modified electrode also showed excellent electrochemical performance for the determination of H2O2 in orange juice as low as 7.5 μM when applying LSV and 2.6 μM using an amperometric technique. It is expected that the modified gold electrode has the potential for applications in bioassays, environmental chemistry, and food chemistry.