A nanostructured sensor of hydrogen peroxide

Abstract

A nanostructured electrochemical sensor of hydrogen peroxide was fabricated growing self-standing Pd nanowires (Pd NWs) into polycarbonate (PC) membranes through a simple metal galvanic deposition. Conditions of deposition were adjusted in order to attain 2–5 μm long Pd wires. Characterization of Pd-NWs was performed by scanning electrode microscopy, energy-dispersive X-ray spectroscopy and X-ray diffraction. Properties of the nanostructured sensor were studied by cyclic voltammetry and chronoamperometry in phosphate buffer—ethanol solution. Addition of pure ethanol to the test solution was essential in order to increase wettability of the nanostructures. Sensing features were compared with those of both compact and nanoparticle film. Results show stable behavior and sensitive response of Pd NWs towards H2O2 with a wide linear dependence over H2O2 concentration for the electrodes consisting of long Pd nanowires/nanotubes, which display an increase of sensitivity and lower limit of detection (LOD) in comparison with the other sensors. Also the linear-response interval widens with electrode specific surface area. Accuracy and selectivity (towards different electroactive species) is excellent.