Nonenzymatic electrochemical assay for hydrogen peroxide detection based on green synthesized MnO₂ nanosheets

Abstract

In this study, manganese oxide (MnO2) nanosheets were successfully prepared with a green and cost-effective method by using Gum Arabic as they both reduce agent and template in the absence of other additives. The composition, crystalline structure and morphology of the synthesized MnO2 nanosheets were studied using different characterization methods. The TEM and FESEM images show that the prepared MnO2 exhibits wrinkle-like nanolayer morphology. Then, the performance of the synthesized MnO2 was investigated for electrochemical detection of hydrogen peroxide (H2O2). The electrochemical sensing of H2O2 based on MnO2 nanosheets modified carbon ionic liquid electrode (MnO2/CILE) was constructed by a pasting method and its electrocatalytic performance was studied using cyclic voltammetry and amperometry. Compared with the bare CILE, the MnO2/CILE electrode exhibited good electrocatalytic behavior for H2O2 reduction in alkaline solutions. The fabricated nonenzymatic H2O2 sensor also showed a linear relationship over an extensive concentration range of 5.0 μM to 10.0 mM (r2 = 0.998) with a LOD of 1.0 μM and a response time of fewer than 5 s. In addition, the developed electrochemical sensor displayed excellent anti-interfering ability, good recovery and also good reproducibility on the H2O2 detection in urine samples. The simple synthesis of MnO2 nanosheets and good electrocatalytic activity reveal the promising usefulness of the fabricated sensor for detection of H2O2.