Boron doped diamond/metal nanocatalyst hybrid electrode arrays for analytical applications

We report on the development of sensor arrays comprising synthetic boron doped diamond (BDD) electrodes modified with metal catalyst nanoparticles. The latter are deposited onto the BDD electrodes surface by a physical vapor deposition process followed by de-wetting under oxygen-free atmosphere in high temperature conditions. The mean size of the particles is in the order of 10 nm, as characterized by scanning electron microscopy (SEM) image processing and small-angle X-ray scattering (SAXS). The particles are made of e.g. platinum, iridium, gold, ruthenium or alloys thereof and showed good adhesion, and good electrochemical reactivity towards a wide range of redox analytes. Sensor arrays composed of 4 BDD electrodes each modified with a different nano-catalyst were mounted and tested for various analytical applications. For instance such a sensor array was able to detect online and discriminate the presence in tap water of the following contaminants: Imidacloprid, Dimethyl methylphosphonate (DMMP) or hydrogen peroxide, chosen for demonstration purpose.