In this study, novel nickel oxide (NiO) flowers like nanostructures were fabricated onto gold coated glass substrate by hydrothermal method using high alkaline pH medium. The structural study of nickel oxide nanostructures was performed by scanning electron microscopy (SEM) and X-ray differaction (XRD) techniques. Nickel oxide nanostructures are highly dense, uniform and possess good crystalline quality. The so prepared structures were investigated for their electrochemical properties by cyclic voltammetry and amperometric techniques. The nickel oxide flower like morphology has shown good electrochemical performances for the oxidation of glucose. The presented sensing material was able to detected glucose in a wide range of concentration of 0.001 mM to 8 mM with a high sensitivity (123 μmA/mM) and regression coefficient of 0.99. Moreover, the NiO nanostructures based sensor is highly reproducible, stable, exhibiting a fast response time and selective in the response. All the obtained results indicate the potential use of this material in the development of enzyme free sensors for the detection of glucose.
Due to increase in the number of diabetes patients, the accurate and sensitive detection of glucose has drawn the attention of researchers towards the simple and cheap fabrication of glucose sensors [
The nickel oxide (NiO) nanomaterial with homogenous size and well defined dispersion is highly demanded for the various applications such as designing ceramic, magnetic, electrochromic and heterogeneous catalytic materials [
The hydrothermal method for the growth of various nanomaterials is also known as super-heated hydrothermal solution based method. Hydrothermal method is considered environmentally benign and it can be used for the growth of various nanomaterials even in strong solvents in the closed system. Moreover, hydrothermal method is inexpensive, simple and yields high purity of desired product, thus it is a highly suitable method from industrial point of view. To date, several methods have been proposed for the synthesis of NiO nanoparticles and nanorods, but few reports have been published for the preparation of porous nanosheets [17,18]. Nickel oxide is the material which can easily be grown by hydrothermal method with high yield on the substrate.
In this work, novel NiO nanoflowers have been synthesized by the hydrothermal method and successfully applied for the development of enzyme free glucose sensor by cyclic voltammetry and amperometric measurements. The sensor electrode is very stable, reproducible, repeatable, sensitive and selective.
Nickel nitrate hexahydrate, hexamethylenetetramine, 25% ammonia, nitric acid d-glucose, ascorbic acid, uric acid and dopamine were purchased from Sigma Aldrich Sweden. All other chemical used were of analytical standard.
The coating of gold layer on the glass substrate was done according to our previous work [
Scanning electron microscopy and X-ray differaction techniques were used for the morphological and crystal studies of prepared NiO nanostructures respectively. The prepared NiO nanostructures were used for the development of enzyme free glucose sensor and the electrochemical measurements were performed by the potentiostat/galvanostat FRA 2 µ Autolab type (III) model. The electrochemical cell used in the proposed work was a three electrode system, NiO nanostructures were used as the working electrode, platinum wire as counter electrode and silver-silver chloride wire as reference electrode. The glucose solution was prepared in the deionized water and all measurements were carried out in 0.1 M NaOH solution with successive addition of glucose solution.
The morphology of as prepared NiO nanostructures was investigated by using the scanning electron microscopy and the obtained nanostructures are shown in
The electro catalytic activity of NiO flower-like nanostructured electrode taword the oxidation of glucose was studied by cyclic voltammetry (CV).