Synthesis of porous Co3S4 for enhanced voltammetric nonenzymatic determination of glucose

Engineering hybrid CuS/Co3S4 nanocages by ion reutilization for highly sensitive glucose sensing platforms

Constructing hybrid hollow nano-electrocatalysts with various transition metal sulfides (TMSs) is highly desirable for sensitive enzyme-free glucose monitoring, but limited research has been conducted due to the constraints of current demanding synthesis technologies. In this study, we integrated CuS and Co3S4 as hybrid nanocages (h-NCs) by advanced synthetic strategies, including coordinated etching and precipitation (CEP) and template ion reutilization. The resulting CuS/Co3S4 h-NCs induced good synergistic effect in electrocatalytic activities, glucose adsorption, and electrical conductivity, as validated by the density functional theory (DFT) calculations. When employed as glucose sensing platforms, electrodes incorporating CuS/Co3S4 h-NCs demonstrated high-performance sensing characteristics, with excellent sensitivities up to 2731.8 μA mM-1 cm2, wide linear range of 0.001-5.6 mM, low detection limit (90 nM), and ideal stability. Moreover, CuS/Co3S4 h-NCs were promising to analyze glucose in human serum with good recoveries ranging from 92.4 % to 96.7 %. These findings underscore the benefits of integrating different TMSs to create hybrid hollow nanomaterials, which optimize glucose sensing platforms and expand the design of high-performance electrocatalysts.

Controlled synthesized of ternary Cu-Co-Ni-S sulfides nanoporous network structure on carbon fiber paper: a superior catalytic electrode for highly-sensitive glucose sensing

BACKGROUND

Efficient monitoring of glucose concentration in the human body necessitates the utilization of electrochemically active sensing materials in nonenzymatic glucose sensors. However, prevailing limitations such as intricate fabrication processes, lower sensitivity, and instability impede their practical application. Herein, ternary Cu-Co-Ni-S sulfides nanoporous network structure was synthesized on carbon fiber paper (CP) by an ultrafast, facile, and controllable technique through on-step cyclic voltammetry, serving as a superior self-supporting catalytic electrode for the high-performance glucose sensor.

RESULTS

The direct growth of free-standing Cu-Co-Ni-S on the interconnected three-dimensional (3D) network of CP boosted the active site of the composites, improved ion diffusion kinetics, and significantly promoted the electron transfer rate. The multiple oxidation states and synergistic effects among Co, Ni, Cu, and S further promoted glucose electrooxidation. The well-architected Cu-Co-Ni-S/CP presented exceptional electrocatalytic properties for glucose with satisfied linearity of a broad range from 0.3 to 16,000 μM and high sensitivity of 6829 μA mM- 1 cm- 2. Furthermore, the novel sensor demonstrated excellent selectivity and storage stability, which could successfully evaluate the glucose levels in human serum. Notably, the novel Cu-Co-Ni-S/CP showed favorable biocompatibility, proving its potential for in vivo glucose monitoring.

CONCLUSION

The proposed 3D hierarchical morphology self-supported electrode sensor, which demonstrates appealing analysis behavior for glucose electrooxidation, holds great promise for the next generation of high-performance glucose sensors.

In situ anchored ternary hierarchical hybrid nickel@cobaltous sulfide on poly(3,4-ethylenedioxythiophene)-reduced graphene oxide for highly efficient non-enzymatic glucose sensing

A ternary hierarchical hybrid Ni@CoxSy/poly(3,4-ethylenedioxythiophene)-reduced graphene oxide (Ni@CoxSy/PEDOT-rGO) is rationally designed and in situ facilely synthesized as electrocatalyst to construct a binder-free sensing platform for non-enzymatic glucose monitoring through traditional electrodeposition procedure. The as-prepared Ni@CoxSy/PEDOT-rGO presents unique hierarchical structure and multiple valence states as well as strong and robust adhesion between Ni@CoxSy/PEDOT-rGO and GCE. Profiting from the aforementioned merits, the sensing platform constructed under optimal conditions achieved a wide detection range (0.2 μM ~ 2.0 mM) with high sensitivity (1546.32 μA cm-2 mM-1), a rapid response time (5 s), an ultralow detection limit (0.094 μM), superior anti-interference performance, excellent reproducibility and considerable stability. Furthermore, the sensor demonstrates an acceptable accuracy and appreciable recoveries ranging from 90.0 to 102.0% with less than 3.98% RSD in human blood serum samples, indicating the prospect of the sensor for the real samples analysis. It will provide a strategy to rationally design and fabricate ternary hierarchical hybrid as nanozyme for glucose assay.

Hybridization of Co3S4 and Graphitic Carbon Nitride Nanosheets for High-performance Nonenzymatic Sensing of H2O2

The development of efficient H₂O₂ sensors is crucial because of their multiple functions inside and outside the biological system and the adverse effects that a higher concentration can cause. This work reports a highly sensitive and selective non-enzymatic electrochemical H₂O₂ sensor achieved through the hybridization of Co₃S₄ and graphitic carbon nitride nanosheets (GCNNS). The Co₃S₄ is synthesized via a hydrothermal method, and the bulk g-C₃N₄ (b-GCN) is prepared by the thermal polycondensation of melamine. The as-prepared b-GCN is exfoliated into nanosheets using solvent exfoliation, and the composite with Co₃S₄ is formed during nanosheet formation. Compared to the performances of pure components, the hybrid structure demonstrates excellent electroreduction towards H₂O₂. We investigate the H₂O₂-sensing performance of the composite by cyclic voltammetry, differential pulse voltammetry, and amperometry. As an amperometric sensor, the Co₃S₄/GCNNS exhibits high sensitivity over a broad linear range from 10 nM to 1.5 mM H₂O₂ with a high detection limit of 70 nM and fast response of 3 s. The excellent electrocatalytic properties of the composite strengthen its potential application as a sensor to monitor H₂O₂ in real samples. The remarkable enhancement of the electrocatalytic activity of the composite for H₂O₂ reduction is attributed to the synergistic effect between Co₃S₄ and GCNNS.

Waste Citrus reticulata Assisted Preparation of Cobalt Oxide Nanoparticles for Supercapacitors

The green, sustainable, and inexpensive creation of novel materials, primarily nanoparticles, with effective energy-storing properties, is key to addressing both the rising demand for energy storage and the mounting environmental concerns throughout the world. Here, an orange peel extract is used to make cobalt oxide nanoparticles from cobalt nitrate hexahydrate. The orange peel extract has Citrus reticulata, which is a key biological component that acts as a ligand and a reducing agent during the formation of nanoparticles. Additionally, the same nanoparticles were also obtained from various precursors for phase and electrochemical behavior comparisons. The prepared Co-nanoparticles were also sulfurized and phosphorized to enhance the electrochemical properties. The synthesized samples were characterized using scanning electron microscopic and X-ray diffraction techniques. The cobalt oxide nanoparticle showed a specific capacitance of 90 F/g at 1 A/g, whereas the cobalt sulfide and phosphide samples delivered an improved specific capacitance of 98 F/g and 185 F/g at 1 A/g. The phosphide-based nanoparticles offer more than 85% capacitance retention after 5000 cycles. This study offers a green strategy to prepare nanostructured materials for energy applications.

Surface charge modulation enhanced high stability of gold oxidation intermediates for electrochemical glucose sensors

Rapid and accurate blood glucose detection is significant for diagnosing and treating diabetes. Herein, ultra-low-content gold nanoparticles were loaded on different metal foams and applied to electrochemical enzyme-free glucose sensors via simple displacement reactions. The structures and properties of the produced catalysts were determined by various characterization methods. The performance of the glucose sensor was examined in relation to the interactions between three different metal substrates and gold. The one with the best performance is the sample of gold nanoparticles grown on copper foam (Au300 Cu Foam). It has the advantage of a porous three-dimensional network, a large electroactive surface area, and the high catalytic activity of gold. The combination of Cu and Au increased the valence state of Au, thus favoring the catalytic activity for glucose oxidation. Cyclic voltammetry and chronoamperometry measurements revealed that Au is responsible for the electrocatalytic oxidation of glucose. The sensitivity of Au300 Cu Foam was found to be 10 839 μA mM^-1 cm^-2 in the linear range of 0.00596-0.0566 mM, with a detection limit (LOD) of 0.223 μM, and 2-3 s response time at 0.4 V vs. Ag/AgCl. The Au300 Cu Foam glucose sensor also offered outstanding stability and anti-interference performance. The prepared Au300 Cu Foam electrode was also successfully applied to detect different levels of glucose in human body fluids, such as saliva. These characteristics make Au300 Cu Foam promising for non-invasive glucose detection.

Copper Cobalt Sulfide Structures Derived from MOF Precursors with Enhanced Electrochemical Glucose Sensing Properties

Nonenzymatic electrochemical detection of glucose is popular because of its low price, simple operation, high sensitivity, and good reproducibility. Co-Cu MOFs precursors were synthesized via the solvothermal way at first, and a series of porous spindle-like Cu-Co sulfide microparticles were obtained by secondary solvothermal sulfurization, which maintained the morphology of the MOFs precursors. Electrochemical studies exhibit that the as-synthesized Cu-Co sulfides own excellent nonenzymatic glucose detection performances. Compared with CuS, Co (II) ion-doped CuS can improve the conductivity and electrocatalytic activity of the materials. At a potential of 0.55 V, the as-prepared Co-CuS-2 modified electrode exhibits distinguished performance for glucose detection with wide linear ranges of 0.001–3.66 mM and high sensitivity of 1475.97 µA·mM⁻¹·cm⁻², which was much higher than that of CuS- and Co-CuS-1-modified electrodes. The constructed sulfide sensors derived from MOF precursors exhibit a low detection limit and excellent anti-interference ability for glucose detection.