Highly sensitive enzyme-free glucose sensor based on CuO-NiO nanocomposites by electrospinning

CuO-NiO nanocomposites have been prepared after calcining fiber mats at 450 degrees C by electrospinning technique. The samples are characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and transmission electron microscopy (TEM) techniques. SEM micrographs depict regular nanofibers without beads. The XRD and TEM results confirm that as-synthesized materials are the composite nanoparticles composed of the crystal phases of CuO and NiO. An enzyme-free glucose sensor has been first fabricated with nanocomposites CuO-NiO-modified on glassy carbon electrode (GCE). Cyclic voltammetry and current-time curve techniques are mainly used to enlighten the electrochemical properties of the modified electrode (CuO-NiO/GCE) in alkaline aqueous solutions. Experimental parameters like applied potential and concentration of modifier on GCE have been optimized, and the analytical performances of as-fabricated biosensor for glucose determination have been investigated in detail. Under optimal conditions (8.0 mu L modifier, +0.55 V), CuO-NiO/GCE exhibits excellent properties in glucose detection for the concentrations with a fast response (similar to 1s), a low detection limit of 0.08 mu M (S/N = 3), a wide range of 0.2 mu M-1.0 mM with a linear correlation coefficient of 0.998 and a very high sensitivity of 4022 mu A mM(-1) cm(-2). In addition CuO-NiO/GCE shows good selectivity, reproducibility and longtime stability. Excellent electrochemical catalytic performance for glucose demonstrates that as-synthesized nanocomposite CuO-NiO is an outstanding and promising electrode material toward glucose.