The effect of surface termination on glucose oxidation using Ni‐modified diamond electrodes

Abstract Abstractauthoren This study describes the decoration of hydrogen‐ and oxygen‐terminated boron‐doped diamond electrodes (BDD) with three different loadings of Ni. The Ni was deposited electrochemically for 600, 400, and 100 s on both hydrogen‐terminated BDD (BDDH) and oxygen‐terminated BDD (BDDO). Scanning electron microscopy (SEM) showed that all Ni particles were roughly spherical in shape, but distribution and size varied with electrode termination: a uniform coverage with a particle size dependent on deposition duration was achieved on BDDH, but on BDDO the particles are deposited primarily along surface ridges and had similar sizes for all three deposition times. The performance of the samples was then tested using glucose sensing as an exemplar application. It was found that glucose oxidation varies greatly between electrodes at concentrations similar to those found in human blood. The variability between the samples was attributed to surface differences between electrodes and the difference in particle location. Amperometry using BDDs decorated with the 100 s Ni deposition gave a stable current response with respect to glucose concentration in the range 0.1–13 mM with much higher glucose oxidation currents being observed for the Ni nanoparticles deposited on the hydrogenated diamond surface.