Sodium dodecyl benzene sulfonate functionalized graphene for confined electrochemical growth of metal/oxide nanocomposites for sensing application

The electrochemical fructose sensor attracts considerable attention in the food industry and for clinical applications. Here, a novel fructose biosensor was developed based on immobilization of highly dispersed CuO-Cu nanocomposites on Graphene that was non-covalently functionalized by sodium dodecyl benzene sulfonate (SOBS) (denoted briefly as SDBS/GR/CuO-Cu). The structure and morphology of SDBS/GR/CuO-Cu were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The electrochemistry and electrocatalysis were evaluated by cyclic voltammetry (CV). The fructose sensing performances were evaluated by chronoamperometry (i-t). Those properties were also compared with that of CuO-Cu. Results revealed the distinctly enhanced sensing properties of SDBS/GR/CuO-Cu towards fructose, showing significantly lowered overpotential of +0.40 V, ultrafast (<1 s) and ultra-sensitive current response (932 mu Am M-1 cm(-2)) in a wide linear range of 3-1000 mu M, with satisfactory reproducibility and stability. Those could be ascribed to the good electrical conductivity, large specific surface area, high dispersing ability and chemical stability of GR upon being functionalized non-covalently by SDBS, as well as the outstanding cation anchoring ability of SDBS on GR to resist aggregation among Cu-based nanoparticles during electro-reduction. More importantly, an improved selectivity in fructose detection was achieved. SDBS/GR/CuO-Cu is one of the promising electrode materials for electrochemical detection of fructose. (C) 2013 Elsevier B.V. All rights reserved.