Controlled synthesis and electrochemical application of skein-shaped NiO nanostructures

A simple, economical and mild solution chemistry method was used to synthesize diverse nickel oxide (NiO) nanostructures employing methionine as a growth-directing agent. The as-synthesized NiO nanostructures were observed to possess a unique skein-shape morphology with uniform spherical distribution. The NiO nanoskein (NiO NSk) formation was extensively studied using X-ray diffraction (XRD), X-ray photoelectron microscopy (XPS), scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) techniques, respectively. The unique NiO NSks exhibited better electrocatalytic activity towards glucose oxidation in alkaline media, enabling the development of a highly sensitive non-enzymatic glucose sensor. The observed analytical properties included high sensitivity (1915 μA mM−1 cm−2), wide linear range (0.1–5.0 mM), low detection limit (0.7 μM), higher stability and reproducibility. Moreover, the sensor is selective in the presence of interfering species such as ascorbic acid (AA), uric acid (UA) and dopamine (DP) during the non-enzymatic glucose sensing. The worthy-of-notice electrocatalytic activity and economical feasible preparation of NiO NSk-shaped electroactive material for direct glucose-sensing applications make the present study of high interest for the fabrication of low-cost devices. A NiO NSk-based glucose sensor has also been employed for glucose determination in human serum with adequate results, suggesting high potential for the routine monitoring of glucose from biotechnology, clinical and food industry samples.