CuO/Cu composite nanospheres on a TiO2 nanotube array for amperometric sensing of glucose

Glucose and UA sensing based on Cu nanoparticle decorated Nif/GO flexible electrode

A novel, green, and facile approach has been developed to construct an ultrasensitive flexible enzyme-less electrochemical sensor on the basis of chitosan and graphene oxide composites decorated with Cu nanoparticles supported on nickel foam (Nif/Cs/GO@Cu), in which GO functions as the intermediate between Nif and Cu nanoparticles. The Nif/Cs/GO@Cu sensing platform was successfully fabricated by the drop casting method to load Cs/GO onto Nif followed by an additionally electrodeposition to support Cu nanoparticles on Nif/Cs/GO. Impressively, the Nif/Cs/GO@Cu exhibited much higher electrocatalytic activity for glucose and UA oxidation as compared to that of Nif or Nif@Cu. For glucose and UA at about 0.6 V and 0.1 V (vs. Ag/AgCl), linearity could be obtained in the concentration ranges 5 µM-4 mM and 5-345 µM; the sensitivities were 16 and 2.5 µA µM-1 cm-2, and the detection limits 83 nM and 0.3 µM, respectively. The improved performance of the composite electrode was ascribed to the synergistic effect of Cu nanoparticles, Nif and GO, in which GO provides high electron conductivity and large surface area to prevent the agglomeration of Cu nanoparticles; Cu nanoparticles and Nif offer abundant active sites towards analytes oxidation. Additionally, the method was applied to determine both analytes successfully in blood serum samples with excellent recovery and also opens up an attractive route to potential applications of the flexible nickel foam-based electrochemical sensor.

Polyvinylpyrrolidone/TiO2 composites' preparation via sol-gel procedure furthered with non-enzymatic glucose sensing and antibacterial effectiveness

An amperometric non-enzymatic glucose sensing based on polyvinylpyrrolidone and titanium dioxide nanocomposites (PVP-TiO2 NCs) fabricated over stainless-steel (SS) electrode was experimented. The electrode was fabricated of PVP-TiO2 NCs onto SS surface through drop casting coating. The NCs and the electrode were analyzed using Fourier transform infrared (FTIR) and UV-visible (UV-Vis) spectroscopy, X-ray diffraction spectra (XRD), X-ray photoelectron spectra (XPS), particle analyzer, scanning electron microscopy (SEM), EDS and transmission electron microscopy (TEM) and Brunauer-Emmett-Teller (BET) analysis for surface. For electrochemical investigation, cyclic voltammetry, electrochemical impedance spectra, including Nyquist plots and Bode plots, and chronoamperometry were adopted. PVP-TiO2/SS-modified electrode manifested high sensitivity of 360.13 µA/mM.cm2, lower detection limit of 756.8 µM and 0 to 13 mM linear range with regression coefficient of R2 = 0.992. The electrode exhibited high stability with good anti-interference tendency against fructose, uric acid, ascorbic acid and sucrose. The modified electrode also performed well in real sample glucose detection. Further, PVP-TiO2 NCs performed appreciably toward antibacterial studies against some Gram-positive and Gram-negative deleterious bacteria, Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus, Shigella flexneri microbes.

Non-Enzymatic Glucose Sensors Involving Copper: An Electrochemical Perspective

Non-enzymatic glucose sensors based on the use of copper and its oxides have emerged as promising candidates to replace enzymatic glucose sensors owing to their stability, ease of fabrication, and superior sensitivity. This review explains the theories of the mechanism of glucose oxidation on copper transition metal electrodes. It also presents an overview on the development of among the best non-enzymatic copper-based glucose sensors in the past 10 years. A brief description of methods, interesting findings, and important performance parameters are provided to inspire the reader and researcher to create new improvements in sensor design. Finally, several important considerations that pertain to the nano-structuring of the electrode surface is provided.

Low dimensional materials for glucose sensing

Biosensors are essential components for effective healthcare management. Since biological processes occur on molecular scales, nanomaterials and nanosensors intrinsically provide the most appropriate landscapes for developing biosensors. Low-dimensional materials have the advantage of offering high surface areas, increased reactivity and unique physicochemical properties for efficient and selective biosensing. So far, nanomaterials and nanodevices have offered significant prospects for glucose sensing. Targeted glucose biosensing using such low-dimensional materials enables much more effective monitoring of blood glucose levels, thus providing significantly better predictive diabetes diagnostics and management. In this review, recent advances in using low dimensional materials for sensing glucose are summarized. Sensing fundamentals are discussed, as well as invasive, minimally-invasive and non-invasive sensing methods. The effects of morphological characteristics and size-dependent properties of low dimensional materials are explored for glucose sensing, and the key performance parameters such as selectivity, stability and sensitivity are also discussed. Finally, the challenges and future opportunities that low dimensional materials can offer for glucose sensing are outlined.

Non-enzymatic glucose sensor based on a g-C3N4/NiO/CuO nanocomposite

In this paper, a non-enzymatic glucose sensor was developed based on a g-C₃N₄/NiO/CuO nanocomposite immobilized on a glassy carbon electrode (GCE). Field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), and Brunauer-Emmett-Teller (BET) were utilized for the characterization of the synthesized g-C₃N₄/NiO/CuO nanocomposite. The electrocatalytic activity of the nanocomposite was investigated by cyclic voltammetry, and the amperometric technique was applied for monitoring glucose. The g-C₃N₄/NiO/CuO/GCE exhibited better electrocatalytic performance than g-C₃N₄/GCE, g-C₃N₄/CuO/GCE and g-C₃N₄/NiO/GCE. Under optimized conditions, the proposed sensor offered a linearity ranging from 0.4 μM to 8.5 mM with a detection limit of 0.1 μM and a sensitivity of 362.12 μA mM^-1 cm^-2. The constructed sensor displayed favorable reproducibility, outstanding selectivity, and long-term performance. These results reveal that the sensor is a promising candidate for blood glucose sensing.