Nonenzymatic multispecies sensor based on Cu-Ni nanoparticle dispersion on doped grapheme

A non -enzymatic sensing platform was developed for detecting glucose and hydrogen peroxide using nitrogen doped graphene decorated with copper-nickel nanoparticles. The synthesized CuNi-NGr composite presented excellent electrocatalytic interaction with glucose and hydrogen peroxide owing to the synergistic effect of copper, nickel and N-graphene. The enhanced performance of the active materials was due to the presence of nitrogen based active sites with high contents in pyridinic and graphitic N as well as the electrocatalytic activity of distributed copper and nickel nanoparticles on graphene. Amperometric analysis showed that the sensitivity of CuNi-NGr based electrode was 7143 mu A.mM(-1).cm(-2) at low (0.01 mu M to 1 mM), and 1030 mu A.mM(-1).cm-(2) at high concentrations (2 to 20 mM) of glucose. The detection responses had corresponding linear ranges as functions of concentration with limit of detection (LOD): 10 nM at S/N =3. For hydrogen peroxide, the fabricated electrode showed detection sensitivity of 954 mu A.mM(-1).cm(-2) with LOD of 10 mu M (S/N = 3) and linear response within 0.01 to 1 mM. On testing, the electrode displayed excellent reproducibility, stability and selectivity for detecting glucose and H2O2 simultaneously in aqueous electrolytes. The sensor was shown to be effective in analyzing glucose and H2O2 present in human urine with excellent recovery. (C) 2016 Elsevier Ltd. All rights reserved.