Controlled synthesis and electrochemical application of skein-shaped NiO nanostructures

Developments of the Electroactive Materials for Non-Enzymatic Glucose Sensing and Their Mechanisms

A comprehensive review of the electroactive materials for non-enzymatic glucose sensing and sensing devices has been performed in this work. A general introduction for glucose sensing, a facile electrochemical technique for glucose detection, and explanations of fundamental mechanisms for the electro-oxidation of glucose via the electrochemical technique are conducted. The glucose sensing materials are classified into five major systems: (1) mono-metallic materials, (2) bi-metallic materials, (3) metallic-oxide compounds, (4) metallic-hydroxide materials, and (5) metal-metal derivatives. The performances of various systems within this decade have been compared and explained in terms of sensitivity, linear regime, the limit of detection (LOD), and detection potentials. Some promising materials and practicable methodologies for the further developments of glucose sensors have been proposed. Firstly, the atomic deposition of alloys is expected to enhance the selectivity, which is considered to be lacking in non-enzymatic glucose sensing. Secondly, by using the modification of the hydrophilicity of the metallic-oxides, a promoted current response from the electro-oxidation of glucose is expected. Lastly, by taking the advantage of the redistribution phenomenon of the oxide particles, the usage of the noble metals is foreseen to be reduced.

Fabrication of RGO-NiCo2O4 nanorods composite from deep eutectic solvents for nonenzymatic amperometric sensing of glucose

A novel reduced graphene oxide supported nickel cobaltate nanorods composite (RGO-NiCo₂O₄) was prepared by a simple ionothermal method in deep eutectic solvents for the first time. Electrochemical results demonstrated that the obtained nanocomposite modified glassy carbon electrode exhibited excellent electrocatalytic performance towards the oxidation of glucose with a wide double-linear range from 1 μM to 25 mM and a low detection limit of 0.35 μM (S/N = 3). NiCo₂O₄ nanorods with many small interconnected nanoparticles provided many electrocatalytic active sites, while RGO with large surface area offered good electrical conductivity. The synergistic effect between NiCo₂O₄ nanorods and RGO contributed to the enhanced sensing ability of the hybrid nanostructure. This sensitive glucose sensor can be also used for the practical detection of glucose in human serum.

Modern Approach to the Synthesis of Ni(OH)2 Decorated Sulfur Doped Carbon Nanoparticles for the Nonenzymatic Glucose Sensor

As a growing aspect of materials science, there are an enormous number of synthesis routes that have been identified to produce materials, particularly through simple methodologies. In this way, the present study focuses on the easiest way to prepare sulfur doped carbon nanoparticles (SDCNs) using a flame synthesis method and has also demonstrated a novel route to synthesize Ni(OH)2 decorated SDCNs by a simple adsorption cum precipitation method. The SDCNs are alternative candidates to prestigious carbon materials such as graphene, carbon nanotubes, and fullerenes. Moreover, SDCNs provide excellent support to the Ni(2+) ion adsorption and initiate the formation of Ni(OH)2. The formation of Ni(OH)2 on the SDCN matrix was confirmed by Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy, X-ray diffraction (XRD), selected area diffraction pattern (SAED), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). After these meticulous structural evaluations, we have described the mechanism for the formation of Ni(OH)2 on an SDCN matrix. The as-prepared Ni(OH)2 decorated SDCN nanocomposites were used as an electrode material for nonenzymatic glucose sensors. The fabricated glucose sensor exhibited a wide linear concentration range, 0.0001-5.22 mM and 5.22-10.22 mM, and a low-level detection limit of 28 nM. Additionally, it reveals excellent selectivity in the potentially interfering ions and also possesses a good stability. The practicality of the fabricated glucose sensor was also demonstrated toward glucose detection in biological samples.