Annealing temperature regulating the dispersity and composition of nickel-carbon nanoparticles for enhanced glucose sensing

Design of electrodes with both excellent electrocatalytic activity and facile synthesis process is the pivotal challenge in the progress of non-enzymatic glucose sensors. In this work, a series of highly dispersed nickel-carbon nanoparticles modified boron doped diamond composite electrodes were fabricated after the boron doped diamond films with a sputtering nickel layer being annealed at different temperature in hydrogen atmosphere. The surface morphology and interface structure of nickel-carbon nanoparticles modified boron doped diamond samples were characterized detailedly with the increase of annealing temperature. The charge transfer of synthesized electrodes was improved with the increasing content of sp2 carbon and the improvement of crystallinity of nickel. Therefore, the volcano-type electrocatalytic performance trend was observed with the composite electrode prepared after annealing at 500 °C presenting the best glucose sensing performance with the sensitivities of 1730 and 1081 μA cm−2 mM−1 in glucose concentration ranges of 0.01–2.12 and 2.12–9.06 mM respectively and a low detection limit of 0.2 μM (S/N = 3).