Interfacing Silver Nanoparticles with Hematene Nanosheets for the Electrochemical Sensing of Hydrogen Peroxide

Abstract

Background: Hydrogen peroxide (H2O2) is an important metabolite that plays a crucial role in enzymatic reactions in living organisms. However, it acts as a reactive oxygen species (ROS) that causes various chronic diseases. The main challenging aspects in detecting H2O2 in body cells are the ultra-lowlevel concentrations and its reactivity. Hence, it is highly essential to develop a platform for H2O2 with high sensitivity and selectivity. Objective: In this work, we report an electrochemical biosensor for hydrogen peroxide (H2O2) by interfacing 3-dimensional silver nanoparticles (Ag-NPs) with 2-dimensional hematene (HMT) nanosheets. Methods: The two-dimensional nanomaterial, HMT, was exfoliated from natural iron ore hematite (α- Fe2O3) and characterized by Raman spectroscopy. The morphology of the Ag nanoparticles and HMT was imaged by scanning electron microscope. Electrochemical characterization of Ag/HMT modified glassy carbon electrode (GCE) was performed by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Results: The fabricated sensor showed a wide linearity range of H2O2 concentrations from 0.99 μM to 1110 μM and a low detection limit of 0.16 μM using CV. Further, the sensor was successfully applied for the electrochemical sensing of hydrogen peroxide using chronoamperometry (CA) from 20 μM to 1110 μM (LOD 5.5 μM). Conclusion: The proposed electrochemical sensor for H2O2 is fast responding with a high sensitivity, and shows selectivity in the presence of biologically important molecules. These consequences suggested that the formation of heterostructures between 2D and 3D nanomaterials unveils the possibility of stable and selective electrochemical sensors for bioanalytics.