Nano TiO 2–Au–KI film sensor for the electrocatalytic oxidation of hydrogen peroxide

Abstract

A glassy carbon and indium tin oxide (ITO) electrodes have been modified with the nano TiO 2–Au–KI film by the adsorption of TiO 2 nanoparticles on the electrodes followed with the electrochemical depositions of nano Au and KI film. Further the nano TiO 2–Au–KI film modified ITO was examined by scanning electron microscopy (SEM) and atomic force microscopy (AFM) techniques. From the microscopic results, the adsorbed nano TiO 2 particles size were found in the range of 70–100 nm. Here the electrochemical depositions of nano Au were formed as a flower shape were in the size range of 230 nm to 1 μm. Next the electrochemical behavior of nano TiO 2–Au–KI film has been examined in different pH solutions. The nano TiO 2–Au–KI film modified glassy carbon electrode (GCE) showed good electrocatalytic activity towards the oxidation of H 2O 2 in phosphate buffer solutions (pH 7.0). The linear range of detection for H 2O 2 oxidation using nano TiO 2–Au–KI film was found as 1 × 10 −5 to 1 × 10 −4 M and 1 × 10 −9 to 1 × 10 −7 M in CV and differential pulse voltammetry (DPV) techniques. The practical applications of nano TiO 2–Au–KI film was evaluated by analyzing the real samples such as antiseptic and contact lens cleaner solutions containing H 2O 2.