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Glucose holds significant importance in disease diagnosis as well as beverage quality monitoring. The high‐efficiency electrochemical sensor plays a crucial role in the electrochemical conversion technology. Ni(OH)2 nanosheets are provided with high specific surface area and redox activity that are widely used in electrochemistry. Conductive metal‐organic frameworks (cMOFs) perfectly combine the structural controllability of organic materials with the long‐range ordering of inorganic materials that possess the characteristic of high electron mobility. Based on the above considerations, the combination of Ni(OH)2 and Ni‐HHTP (HHTP=2,3,6,7,10,11‐hexahydroxytriphenylene) as an electrode modification material is designed to enhance electrochemical performance. In this work, to improve glucose detection, a sequence of Ni(OH)2@NiCo‐HHTP and NiM‐LDH@Ni‐HHTP (M=Co2+, Mn2+, Cu2+, LDH=layered double hydroxide) are successfully synthesised by doping metals into Ni‐HHTP and Ni(OH)2, respectively. As a result, NiCu‐LDH@Ni‐HHTP showed the best excellent glucose detection sensitivity. [ABSTRACT FROM AUTHOR]

Developing functional electrode materials for enzyme-free glucose electrochemical sensing is indispensable and challenging for rapid detection and instant diagnosis. Optimizing the microstructure of electrodes to enhance molecule accessibility, facilitate rapid mass transfer, and enlarge electrochemical active surface area is critical prerequisite for improving the electrochemical analytical performance. Herein, we develop a flexible graphene foam electrode with high conductivity and multilayer channel structure achieving efficient enzyme-free glucose sensor through one-step electrodeposition of nickel. The almost defect-free graphitic structure and layered multi-channel configuration enable the graphene foam to exhibit high conductivity, large specific surface area, and excellent mechanical performance. These properties result in efficient electron transmission and mass transfer, enabling the graphene foam to function as an excellent electrode substrate material in electrochemical sensors. Thus, the detecting electrode (Ni/GF) produced by electrodepositing nickel on graphene foam, demonstrates elevated sensitivity (1719.4 μA mM−1 cm−2), low limit of detection (0.2 μM), exceptional stability, and excellent flexibility for glucose detection. More importantly, the prepared electrode has been successfully applied to artificial sweat and tea, indicating its practical utility. The attractive analytical outcomes suggest that our layered multi-channel graphene foam has the potential to serve as a crucial foundational working electrode for designing efficient electrochemical sensor. [Display omitted] • The graphene foam (GF) featuring a multi-channel structure was developed. • The GF can be used as a flexible three-dimensional scaffold for loading active materials and improving electron transfer. • The GF decorated with Ni layer (Ni/GF) is proposed as a highly efficient electrode for the enzyme-free glucose detection. • Excellent performance of Ni/GF electrode in real samples confirms their potential for practical applications. [ABSTRACT FROM AUTHOR]

Glucose electrochemical sensors based on nanostructures of CuO/Cu(OH)2 onto graphene paper were prepared by thermal (solid) and nanosecond pulsed laser (molten phase) dewetting of a CuO layer 6 nm thin deposited by sputtering. Dewetted systems, obtained without the use of any binder, act as array of nanoelectrodes. Solid state and molten phase dewetting produce nanostructures of copper oxide-hydroxide with different average size, shape and surface composition. Molten phase dewetting originates particles with size below 100 nm, while solid state dewetting produces particles with average size of about 200 nm. Moreover, molten phase dewetting produce drop-shaped nanostructures, conversely nanostructures derived from solid state dewetting are multifaceted. X-ray photoelectron spectroscopy (XPS) characterization revealed that the surface of nanostructures is formed by a copper(II) species CuO and Cu(OH)2. Shape of anodic branch of the cyclic voltammograms of glucose in alkali solution evidenced a convergent diffusion mechanism. Analytical performances in amperometric mode are as good as or better than other sensors based on copper oxide. Amperometric detection of glucose was done at potential as low as 0.4 V versus saturated calomel electrode by both types of electrodes. Linear range from 50 ÎĽ M to 10 mM, sensitivity ranging from 7 to 43 ÎĽ A cmâˆ'2 mMâˆ'1 and detection limit of 7 ÎĽ M was obtained. Good analytical performances were obtained by laser dewetted electrodes with a low copper content up to 1.2 by atoms percentage of the surface. Analytical performance of the proposed electrodes is compliant for the determination of glucose both in blood serum, saliva or tear. [ABSTRACT FROM AUTHOR]

Nanostructures of Cu2O/CuO hydroxide suitable for the electrochemical determination of glucose are obtained by solid‐state dewetting of CuO layers 6, 8, and 31 nm thin deposited by sputtering onto 240 μm‐thick graphene paper. Solid‐state dewetting in nitrogen produces a partial decomposition of CuO into Cu2O and Cu. X‐ray diffraction patterns reveal the presence of high‐index crystallographic facets, which are reactive and useful toward glucose oxidation to gluconolactone. Typically, morphology studied by scanning electron microscopy reveals faceted nanoparticles with an average size below 200 nm. X‐ray photoelectron spectroscopy shows that the nanostructure surfaces of Cu2O and metallic copper exposed to natural ambient are promptly reoxidized and hydroxidized to a mixture of CuO and Cu(OH)2. Electrochemical characterization in amperometric mode reveals linear response to glucose concentration in the range from 50 to 10 × 10−3 m, sensitivity up to 83 μA cm−2 mm−1, and limit of detection up to 3.6 × 10−6 m. Good combination of low cost and simplicity of preparation with low limit of detection, high sensitivity, and wide linear range makes the proposed electrodes suitable for a variety of applications ranging from health to food and beverage industries. [ABSTRACT FROM AUTHOR]