A Hydrogen Peroxide Electrochemical Sensor Based on Core-Shell MnO₂-SiO₂-Ag Nanocomposite

Abstract

A core-shell nanocomposite of manganese dioxide-silicon dioxide-silver nanoparticles (MnO2-SiO2-Ag) was synthesized via hierarchical assembly successfully and further fabricated in an electrochemical sensor of hydrogen peroxide (H2O2). The composites were characterized by transmission electron microscope (TEM), X-ray diffractometer (XRD), UV-visible spectroscopy and Fourier transform infrared spectrum (FTIR). The electrochemical investigation conducted by cyclic voltammetry, electrochemical impedance spectroscopy and chronoamperometry, reveals that the composites have excellent catalytic property toward H2O2. The sensor could detect H2O2 with a wide linear range from 2.0 μmol·L−1 to 8.86 mmol·L−1 and a low detection limit of 0.7 μmol·L−1 in N2-saturated phosphate buffer solution (PBS, pH 7.2). The sensor also shows reproducible and good stability. The study indicates MnO2-SiO2-Ag nanocomposite has great potential in the further practical applications.