Prussian blue@Au nanoparticles/SiO2 cavity/ITO electrodes: application as a hydrogen peroxide sensor

We developed a Prussian blue@Au nanoparticles/SiO2-cavities/indium tin oxide (ITO) electrode for a novel non-enzymatic hydrogen peroxide detection. The ordered SiO2 cavities were fabricated on the ITO electrode using the close-packed ordered polystyrene spheres (PS) as templates. The PB@Au nanoparticles were prepared using a two-step process in which gold nanoparticles were deposited at the bottom of the SiO2 cavity by electrochemical methods, while Prussian blue was introduced into the AuNP surface by chemical deposition. The submicron-sized conductive region and the domain-limiting effect of the insulating SiO2 cavity give the electrode the characteristics of a microelectrode, enabling it to exhibit unique electrochemical properties during the electrochemical reduction of H2O2. The proposed PB@Au/SiO2 cavity/ITO electrode was further used for detecting H2O2 with a wide linearity range of 0.08–8 mM and a low detection limit of 0.3 μM.