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An amperometric non-enzymatic glucose sensor was developed based on nitrogen-doped graphene with dispersed copper nanoparticles (Cu-NGr). The sensing element was tested in conjunction with a modified glassy carbon electrode for glucose detection. The Cu-NGr composite was prepared by one pot synthesis from a mixture of graphene oxide, copper nitrate and uric acid, followed by thermal annealing at 900°C for 1h. Detailed characterizations showed homogeneous copper nanoparticle dispersion and the presence of significant proportion of graphitic nitrogen. The developed electrode presented high electrocatalytic activity towards glucose through synergetic effect of copper nanoparticles and nitrogen-doped graphene. Amperometric analysis confirmed high glucose sensitivity and ultra-low detection of 10nM glucose over a linear range. The sensor was tested for direct application to detect glucose in food samples for which the sensor displayed high selectivity with excellent reproducibility and recovery in complex food materials., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

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 μA.mM −1 .cm −2 at low (0.01 μM to 1 mM), and 1030 μA.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 μA.mM −1 .cm −2 with LOD of 10 μM (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 H 2 O 2 simultaneously in aqueous electrolytes. The sensor was shown to be effective in analyzing glucose and H 2 O 2 present in human urine with excellent recovery. [ABSTRACT FROM AUTHOR]