Green synthesis of copper oxide nanoparticles decorated reduced graphene oxide for high sensitive detection of glucose.

A non-enzymatic glucose sensor based on pencil graphite electrode (PGE) modified by copper oxide nanoparticles decorated reduced graphene oxide (CuO(NP)/rGO-PGE) was prepared. XRD patterns showed partially electrochemically reduction of GO and monoclinic structure of CuO on the PGE. The prepared CuO(NP)/rGO exhibited a nanoporous structure by scanning electron microscopy (SEM). Transmittance electron microscopy (TEM) revealed copper oxide nanoparticles were well distributed on rGO and had semispherical shapes with diameter 3-5 nm. Cyclic voltammetry at CuO(NP)/rGO-PGE showed the immobilized CuO(NP)s were highly stable in alkaline solutions and had high electrocatalytic activity toward glucose oxidation. Using amperometry, the detection limit of [0.091 (±0.003) μM] and concentration sensitivity of [4760 (±3.2) μA mM-1 cm-2] for glucose was obtained at optimum conditions. The applicability of the sensor was evaluated to determine the glucose concentration in human blood serum samples and the experimental results were comparable with those measured by traditional spectrophotometric methods. The preparation of CuO(NP)/rGO-PGE was reproducible, very simple, fast and inexpensive for practical application.