Carbon Screen-Printed Electrodes Modified With Composite Films Based On Silica For H2o2 Determination

In this study, a nanostructured screen-printed carbon electrode (nanoSPCE) was modified with silica-based composite films containing metal oxides (MnO2 or CuO) without and with graphene oxide (GO). According to scanning electron microscopy results, uniform thin films with encapsulated metal oxides and GO were formed on the surface of nanoSPCEs. The electrochemical parameters of the modified electrodes were measured by cyclic voltammetry for the non-enzymatic determination of H2O2. Because of the combined action of GO and metal oxides, the modified electrodes have improved electrocatalytic performance for the determination of H2O2 in phosphate buffer solutions. NanoSPCE/MnO2/GO/SiO2 and nanoSPCE/CuO/GO/SiO2 exhibited stable current-voltage responses and good sensing for H2O2 with a wide linear detection range of 0.005-0.5 mM and 0.05-0.3 mM, respectively.