Synthesis of differently sized silver nanoparticles on a screen-printed electrode sensitized with a nanocomposites consisting of reduced graphene oxide and cerium(IV) oxide for nonenzymatic sensing of hydrogen peroxide

The authors describe a screen-printed and disposable electrode for the nonenzymatic determination of hydrogen peroxide (H2O2). It is based on the controllable synthesis and deposition of silver nanoparticles (AgNPs) of different sizes on a nanocomposite consisting of reduced graphene oxide and cerium (IV) oxide (rGO@CeO2) that was placed on a screen-printed electrode (SPE). X-ray powder diffractometry and Fourier transform infrared spectroscopy were used to characterize the composition of the hybrid nanomaterials. Electrochemical impedance spectroscopy and scanning electron microscopy were employed to study the interfacial properties and morphologies of different electrodes. The sensor was investigated by cyclic voltammetry and chronoamperometry (i-t plots). After optimization, the modified SPE showed a good performance towards the electrocatalytic reduction of H2O2, best at a working potential of -0.3 V (vs. Ag/AgCl). Features of merit include a broad linear analytical range extending from 0.5 mu M to 12 mM, and a limit of detection as low as 0.21 mu M (at an S/N ratio of 3). The sensor is simple, quick, stable and reliable. It was applied to the determination of H2O2 in (spiked) contact lens care solutions with good accuracy and recovery.