The effect of heat treatment time on the carbon-coated nickel nanoparticles modified boron-doped diamond composite electrode for non-enzymatic glucose sensing

Abstract

A series of carbon-coated nickel nanoparticle modified boron-doped diamond (Ni(C)-BDD) composite electrodes with different amounts of carbon coating were fabricated. The effects of heat treatment time on the electrochemical performance of the Ni(C)-BDD electrodes for glucose detection were investigated. The morphology and composition of the composite electrodes were assessed by scanning electron microscopy and Raman spectroscopy. Ni catalyzed the carbon inside boron-doped diamond (BDD) into graphite layer which was coated on the surface of Ni nanoparticles at high temperature. As thermal catalytic treatment time prolonged, the carbon coated on Ni nanoparticles became more and more obvious. Electrochemical results indicate that the Ni(C)-BDD composite electrode shows excellent electrochemical performance for glucose oxidation. Compared to the 5min-Ni(C)-BDD electrode, the 30 and 60min-Ni(C)-BDD electrodes need longer heat treatment time, and in return the Ni nanoparticles are covered by more carbon layer, and the current response after one-month measurement is 81.11% and 81.55%, respectively. The 60min-Ni(C)-BDD electrode has a sensitivity of 1130 and 420 μA·mM−1·cm−2 in the detection range of 1μM to 4mM and 4 to 10mM, respectively, its LOD is 0.69μM, and the current response after one month's test remains 81.55% of the initial value. The composite electrode has high sensitivity, good selectivity and long-term stability for glucose detection.