Facile Synthesis of ZnMnO@rGO Microspheres for Ultrasensitive Electrochemical Detection of Hydrogen Peroxide from Human Breast Cancer Cells.

Mixed transition-metal oxides have witnessed increasing attention in catalysts and electrocatalysts. Herein, reduced graphene oxide-wrapped ZnMnO microspheres (ZnMnO@rGO) were facilely synthesized through the solvothermal technique. The microstructure and morphology of ZnMnO@rGO microspheres were analyzed under Raman, X-ray photoelectron, X-ray diffraction, and energy-dispersive spectroscopies and scanning electron microscopy. The synthesized ZnMnO@rGO was employed as an excellent electrocatalyst for the reduction of hydrogen peroxide (HO). The ZnMnO@rGO-modified glassy carbon electrode (ZnMnO@rGO/GCE) exhibited a linear detection to HO in a wide concentration range of 0.03-6000 μM with a detection limit of 0.012 μM. The biosensor was evaluated to determine HO secreted by human breast cancer cells (MCF-7), indicating its promising applications in physiology and diagnosis.