Synthesis of Co3O4-NiO nano-needles for amperometric sensing of glucose

In this paper, needle-like Co3O4-NiO nanocomposites with excellent electrocatalytic activity were served as electrode matrix for constructing novel electrochemical glucose sensor. The Co3O4-NiO nanocomposites were synthesized via a simple two-step procedure, showing a uniform geometric size with average length and diameter about 465 and 25 nm, respectively. The Co3O4-NiO composites exhibited random distributed nano-needles were investigated by scanning electron microscopy, transmission electron microscopy, X-ray diffraction and X-ray photoelectron spectroscopy. In addition, the needle-like Co3O4-NiO nanocomposites were used as an electrode material for constructing nonenzymatic electrochemical glucose sensor and their electrocatalytic performances were evaluated by cyclic voltammetry and amperometry techniques. The sensor exhibited a wide linear response in the 1 mu M to 3.4 mM and 3.4 mM to 12.2 mM glucose concentration ranges, a low detection limit of 0.81 mu M and a high sensitivity of 62 mA M-1 cm(-2) (S/N = 3). Furthermore, the prepared sensor was utilized to detect the glucose levels in human serum, and satisfactory results were obtained. It demonstrated that needle-like Co3O4-NiO nanocomposites are promising materials in practical electrochemical sensing.