Synthesis and characterization of MgO/ZnO composite nanosheets for biosensor

• Novel MgO/ZnO composite nanosheets with zigzag edges were synthesized.
• The interim ZnO as a template were introduced to describe the formation process.
• A hydrogen peroxide biosensor was developed on the base of these composite nanosheets.
• The corresponding biosensor showed high sensitivity, wide linear response range, and low detection limit.

MgO/ZnO composite nanosheets with a molar ratio of Mg to Zn of 20/1 were synthesized successfully by a thermal evaporation method. The morphology and structure of the composite nanosheets were characterized and the results demonstrated that the composite nanosheets were polycrystalline with an average thickness of about 5–10 nm. Different from the former reports, it was noted that many composite nanosheets had zigzag edges with angles of 120°. The interim ZnO as a template were introduced to describe the formation of these novel MgO/ZnO nanosheets. Electrochemical experiments showed that these MgO/ZnO composite nanosheets could be used as good materials for immobilization of horseradish peroxidase for the fabrication of efficient H2O2 biosensor.