A novel δ-MnO2 with carbon nanotubes nanocomposite as an enzyme-free sensor for hydrogen peroxide electrosensing

Abstract

We have reported the synthesis and application of a δ-MnO₂ with carbon nanotubes (δ-MnO₂/CNTs) nanocomposite as an enzyme-free sensor for the detection of H₂O₂ through an electroreduction reaction, where δ-MnO₂ serves as the catalytic center and CNTs as the highly conductive base material. The δ-MnO₂/CNTs nanocomposite was synthesized via a simple and single-step hydrothermal process in alkaline solution without using any surfactants or templates. The electrochemical properties of the δ-MnO₂/CNTs on a glassy carbon electrode were investigated by cyclic voltammetry, and amperometry. It was found that, under optimized conditions, the sensor fabricated electrode provides linear amperometric responses for H₂O₂ in a large concentration range from 0.05 to 22 mM and a detection limit of 1 μM with a comparatively high sensitivity of 243.9 μA mM⁻¹ cm⁻². In addition, the δ-MnO₂/CNTs modified GCE exhibits excellent selectivity, and good reproducibility for H₂O₂ detection. It is promising that the proposed H₂O₂ sensor can be used as an effective tool to measure the H₂O₂ in practical samples.