Palladium nanostructures from galvanic displacement as hydrogen peroxide sensor

Electroless plating of palladium on silicon has been developed, resulting in the formation of palladium films and nanoparticles. The deposition process has been monitored by atomic and Kelvin probe force microscopies (AFM/KPFM), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) in order to understand the deposition mechanism. A fabrication process is developed to yield a high density of Pd particles, while ensuring the formation of a palladium thin film underneath. The formed substrates have been used as amperometric sensors without further modification for the determination of hydrogen peroxide concentrations. The substrates are found to exhibit excellent linear electrocatalytic response down to the micromolar range and under an applied potential of 0.0 V, with the lowest quantifiable concentration of 1 μM. The simplicity in substrate fabrication coupled with the potential for integration in microfabrication processes, as well as the low applied potential needed in the measurements, offers the possibility of using the device in enzymatic biosensors with low interference signals.