Spectroelectrochemical Evaluation of a ZnO Optically Transparent Electrode Prepared by the Spin-spray Technique

We present a novel zinc oxide (ZnO) optically transparent electrode (OTE) prepared by the spin-spray technique for spectroelectrochemistry. The spin-spray technique can deposit ZnO film at a low cost, high rate deposition, and at a low temperature (<100 °C) in a single step. This new technique provides good optical transparency and electrical conductivity for ZnO. The electrochemical and spectroelectrochemical properties of the ZnO electrode were investigated for varying thicknesses of ZnO using methylene blue as a redox indicator. A ZnO OTE chip that includes three electrodes on a glass chip was developed for thin-layer spectroelectrochemistry. Moreover, the ZnO films were successfully applied in an electrochemical-localized surface plasmon resonance (LSPR) method for methylene blue detection by using them as a transparent conducting substrate for loading gold nanoparticles.