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

Abstract

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.