A highly sensitive H2O2 sensor based on zinc oxide nanorod arrays film sensing interface

Abstract

A highly sensitive sensor for the determination of H₂O₂ is presented in this paper. The constant-current electrochemical deposition (ECD) was used to synthesize ZnO nanorod arrays on indium-tin oxide (ITO) substrate. It was found that high temperature sintering could improve the intensity and stability of the photocurrent of ZnO nanorod arrays modified electrode. Meanwhile, it was found that H₂O₂ could greatly enhance the photocurrent of ZnO nanorod arrays modified electrode, based on which a highly sensitive sensor could be developed for the detection of H₂O₂ with a detection limit of 2.0 × 10⁻¹³ mol L⁻¹. The ZnO nanorod electrode was characterized by XRD, SEM and XPS. The XPS results showed that H₂O₂ removed the lattice oxygen from ZnO surface and then resulted in the increase of photocurrent. It is believed that more highly sensitive sensors can be developed to detect the bioactive compounds which can produce H₂O₂ through an enzymatic reaction.