Nanostructured palladium doped nickel electrodes for immobilization of oxidases through nickel nanoparticles.

The present investigation deals with the development, characterization and application of nanostructured Pd doped Ni electrodes (Pd@Ni), which uses the electrochemical properties of Pd in synergy with the magnetic properties of Ni for biosensors development. The Pd@Ni electrodes have been characterized by X-ray diffraction, scanning electron microscopy with energy dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy. It has been shown that palladium presented spherical assemblies ranging 150–200 nm medium diameter size that covers large areas of the electrode surface while metallic nickel, which confers magnetic properties, showed a uniform granular structure with sizes between 20 and 50 nm. Cyclic voltammetry and electrochemical impedance spectroscopy were performed to understand the electrochemical process at the Pd@Ni electrodes in neutral media. The Pd@Ni electrodes were applied for the electrochemical detection of H 2 O 2. Finally, Ni nanoparticles (NiNP) functionalized with the model enzyme glucose oxidase (GOx-NiNP) have been attached to the Pd@Ni electrode solely through magnetic interactions, and the obtained GOx-NiNP/Pd@Ni biosensor applied for glucose determination in aqueous solutions by fixed potential amperometry at −0.05 V (vs Ag/AgCl) with reduced interferences. Image 10197 • Palladium doped nickel electrodes and nickel nanoparticles. • Benefits from the catalytic effect of Pd and the magnetic properties of Ni. • Oxidase immobilization solely through magnetic interactions. • Palladium doped nickel electrodes for the detection of H 2 O 2. • Biosensor operates at low potential values avoiding interfering compounds. [ABSTRACT FROM AUTHOR]