Preparation of PdCu Decorated Screen Printed Carbon Electrodes for Non-Enzymatic Hydrogen Peroxide Sensors

In the last couple of years, Pd and its alloys gained considerable interest for non-enzymatic hydrogen peroxide (H₂O₂) and glucose sensing applications. Although Pd shows lower catalytic activity than Pt, its eco-friendly nature and low cost make it a promising catalyst material for many applications ranging from fuel cells to biosensors. Great effort has been devoted to improve the catalytic activity of Pd using various methods such as preparation of Pd nanostructures with different morphologies and alloy formation with transitional metals. In this work, Pd and PdCu alloys with varying compositions were deposited via a simple electrodeposition method on screen printed carbon electrodes (SPCEs) to fabricate non-enzymatic H₂O₂ sensors. Our results showed that co-deposition of Pd and Cu improved the electrochemical activity of the prepared electrodes significantly compared to pure Pd decorated SPCEs. The highest electrochemical activity was obtained from PdCu electrodes with (7:3) molar ratio. The sensitivity of this electrode to H₂O₂ was found to be -390.5 µA mM^-1 cm^-2 at the working potential of -300 mV (vs. Ag/AgCI). In addition, the electrodes showed a wide linear range of 0.5-6 mM and a low detection limit (0.3 µM).