Electrochemical Oxidation Of Glucose Research Articles

Oxophilic Sn to promote glucose oxidation to formic acid in Ni nanoparticles.

The electrochemical glucose oxidation reaction (GOR) presents an opportunity to produce hydrogen and high-value chemical products. Herein, we investigate the effect of Sn in Ni nanoparticles for the GOR to formic acid (FA). Electrochemical results show that the maximum activity is related to the amount of Ni, as Ni sites are responsible for catalyzing GOR via the NiOOH/Ni(OH)2 pair. However, the GOR kinetics increases with the amount of Sn, associated with an enhancement of the OH- supply to the catalyst surface for Ni(OH)2 reoxidation to NiOOH. NiSn nanoparticles supported on carbon nanotubes (NiSn/CNT) exhibit excellent current densities and direct GOR via C-C cleavage mechanism, obtaining FA with a Faradaic efficiency (FE) of 93% at 1.45 V vs. reversible hydrogen electrode. GOR selectivity is further studied by varying the applied potential, glucose concentration, reaction time, and temperature. FE toward FA production decreases due to formic overoxidation to carbonates at low glucose concentrations and high applied potentials, while acetic and lactic acids are obtained with high selectivity at high glucose concentrations and 55 °C. Density functional theory calculations show that the SnO2 facilitates the adsorption of glucose on the surface of Ni and promotes the formation of the catalytic active Ni3+ species.

Glucose oxidation on gold in alkaline solution: A DEMS and microkinetic modeling study

The mechanism and kinetics of the electrochemical oxidation of glucose on gold surfaces in 0.1 M NaOH solution are investigated by rotating disk electrode and differential electrochemical mass spectrometry coupled to microkinetic modeling. For this purpose, the glucose mass-transport parameters (solution viscosity and density, glucose diffusion coefficient) were determined in the relevant conditions. Koutecký–Levich analysis of rotating disk electrode current-potential curves revealed that the glucose oxidation reaction (GOR) follows a one-electron mechanism at 0.6 V vs RHE, while H2 production could be evidenced by DEMS in this potential range. This suggests that the glucose oxidation selectively produces gluconate at 0.6 V vs RHE through an electrochemical oxidative dehydrogenation (EOD) mechanism. A microkinetic model of the current-potential curves was developed, taking into account the hydrogen electrode reactions kinetics, the dissociative adsorption/desorption of glucose, and the glucose electrooxidation on gold surfaces. The dissociative adsorption of glucose was found to be the rate-determining step of the reaction. It is also revealed that the release of anodic H2 through the Tafel step is triggered by the consumption of the adsorbed reaction intermediates. The gluconate electrooxidation into further products has to be considered for potential above 0.7 V vs RHE.

Two-Dimensional Nanorod-Shaped Co(II) Coordination Polymer on Three-Dimensional Metallic Foam: A Hybrid Platform for Electrochemical Oxidation of Glucose.

This study unveils a novel electrochemical biosensor for monitoring glucose in biological fluids by employing nanorods of a cobalt-bispyridyl/dicarboxylate framework grown in a layer-by-layer manner on a highly porous nickel substrate. The hybrid microporous system has a bicatalytic effect on glucose oxidation due to the synergistic catalytic impact of the nickel and cobalt ions with varying oxidation states as electroactive sites. In addition, the controlled growth of inorganic-organic frameworks changes the mechanism of electron transfer from a diffusion-controlled process to an adsorption-controlled process, thus yielding a low onset oxidation potential (∼0.21 V/Ag-AgCl) and a high current intensity (∼1 mA) for the oxidation of glucose in alkaline media. A fast response time (∼2 s) and a reasonably high sensitivity (0.14 μA μM-1) within a broad linear range (40-360 μM) have determined the suitability and superiority of the hybrid electrode for glucose monitoring compared to many metal-organic-based biosensors. The facile fabrication process of the Co(II) coordination polymer/Ni substrate with a large surface area that benefits from the synergetic catalytic activity of nickel-cobalt hybrids may pave the way for the development of novel hybrid electrodes for biosensors and direct glucose fuel cells.

A Novel Synthesis of Nickel Carbide Modified Glassy Carbon Electrode for Electrochemical Investigation of Archetypal Diabetes Biomarker in Human Serum and Urine Samples

We began with an exploration of a novel method for non-enzymatic glucose sensing through the direct electrochemical oxidation process using an annealed Nickel carbide (Ni3C) modified glassy carbon electrode (GCE). We cover the synthesis and detailed characterization of Ni3C, the modification process of the electrode, and its application in the electrocatalytic detection of glucose in human blood and urine samples. Ni3C, known for its high charge transfer efficiency, exceptional stability in harsh environments, and outstanding electrochemical activity, was prepared through an annealing method. The produced Ni3C, characterized by a nanoplate structure ranging from 20 to 50 nanometers, was applied to a GCE to benefit from its extensive surface area and structural robustness. Electrochemical impedance spectroscopy and cyclic voltammetry confirmed the superior electrocatalytic properties and charge transfer capabilities of Ni3C/GCE over the unmodified GCE. The glucose detection was achieved by the direct electrochemical oxidation of glucose on the modified electrode, showcasing a linear detection range from 0.05 to 2236 μM and an impressively low detection limit of 0.0186 μM. This research underscores the effectiveness of Ni3C/GCE as durable, efficient, and reliable tools for the non-enzymatic electrochemical sensing of glucose, providing new prospects for diabetes monitoring.

Electrochemical oxidation of glucose in alkaline environment—A comparative study of Ni and Au electrodes

The glucose oxidation reaction (GOR) was studied on Au and Ni electrodes by cyclic voltammetry (CV), rotating disk electrode (RDE) measurements coupled with Koutecky–Levich analysis, Differential Electrochemical Mass Spectrometry (DEMS), in situ Fourier Transform Infrared spectroscopy (FTIRS) and High Performance Liquid Chromatography (HPLC) analysis of the reaction products after electrolysis in potentiostatic mode under continuous flow conditions. This study allowed to identify the reaction products and propose tentative reaction mechanisms. On gold, glucose is adsorbed on metallic sites through its anomeric function (C1) resulting in the formation of gluconate as the main GOR product at potentials close to 0.6 V vs. RHE, with a selectivity towards gluconate close to 100% and a projected faradaic efficiency of ca. 70%. The conversion rate is rather low, close to 20%, due to poisoning of the surface, leading to a strong deactivation. At potentials above 0.7 V vs. RHE, the selectivity towards gluconate decreases and non-selective GOR oxidation proceeds through CC bond cleavage. On nickel, the GOR occurs at high potentials (close to 1.2 V vs. RHE) on Ni(OH)2 and NiOOH sites, and proceeds through C1C2 bond breaking, resulting in arabinose and formate. At higher potentials, the selectivity towards arabinose decreases, formate being the main reaction product.

NiCu-based catalysts with high selectivity for electro–oxidation of glucose to formic acid

Electrochemical oxidation of glucose to high valuable chemicals is an attractive strategy to realize sustainable development. Herein, we report that nanostructured NiCu oxide (NiCuO) reveal excellent activity and selectivity toward electrooxidation of glucose, which is synthesized from bimetallic alloy-NiCu on three-dimensional Ni foam. Only 1.15 V and 1.39 V are needed to reach 10 and 100 mA cm−2 for glucose oxidation reaction (GOR), respectively. The integrated two-electrode glucose electrolytic cell can deliver 10 mA cm−2 at the voltage of 1.29 V. It is 360 mV less than overall water splitting at the same condition. The main liquid product of glucose electrooxidation is formic acid, and its Faradaic Efficiency and selectivity are around 94.6 % and 93.3 %, respectively. Density functional theory (DFT) calculations is applied to confirm that NiCuO catalyst could optimize the Gibbs free energy in reaction, which could enhance catalytic activity toward GOR. This study shows that electrolytic glucose is a promising and energy-saving technology for high value-added chemical production and clean energy supply in the future.

Selecting effective eletrocatalyst from Cu single-atoms and nanoparticles for realizing highly sensitive electrochemical sensing of glucose and H2O2.

Which is more suitable as a sensing material between metal single-atoms and nanoparticles? Herein, electrocatalytic behaviors of copper single-atoms (Cu SAs) and copper nanoparticles (CuNPs) toward H2O2 reduction and glucose oxidation were studied. Surprisingly, the electrocatalytic activity of Cu SAs and CuNPs showed significant differences in H2O2 reduction and glucose oxidation. Compared with CuNPs, Cu SAs exhibit outstanding activity in the electrocatalytic reduction of H2O2 but exhibit weak activity in the electrocatalytic oxidation of glucose. On the contrary, CuNPs exhibit excellent activity in the electrochemical oxidation of glucose but have very weak electrocatalytic activity towards H2O2 reduction. DFT results show that H2O2 reduction is more favourable with Cu SAs; however, the electrochemical oxidation of glucose with CuNPs requires overcoming much lower energy barriers than that with Cu SAs. This study proves that both metal single-atoms and nanoparticles are not omnipotent, which provides ideas for constructing highly active sensing materials.

In situ growth of self-supported CuO nanorods from Cu-MOFs for glucose sensing and elucidation of the sensing mechanism.

Herein, we present a simple and mild method to in situ prepare CuO nanostructures for non-enzymatic glucose sensing. A Cu-metal organic framework (Cu-MOF) precursor was first directly grown on a pencil lead electrode with 3D graphene-like surfaces (EPLE) and then in situ transformed into CuO nanorods. The CuO nanorod-modified EPLE (CuO/EPLE) shows high sensitivity (1138.32 μA mM-1 cm-2), fast response time (1.5 s) and low detection limit (0.11 μM) for glucose oxidation. It has been found that NaOH promoted the generation of ˙OH groups and Cu(III) on the CuO surface, which then facilitated the electrochemical oxidation of glucose. Signals characteristic of hydroxyl and carbon-centered radical adducts were detected by EPR. Furthermore, the CuO/EPLE sensor also shows good accuracy in glucose determination in human serum samples.

Nickel–Cobalt Selenide Electrocatalytic Electrode toward Glucose Oxidation Coupling with Alkaline Hydrogen Production

Electrochemical glucose oxidation reaction (GOR) is a promising alternative anodic reaction to water oxidation reaction for various electrochemical oxidation reactions owing to the relatively low thermodynamic potential of GOR and the abundant source of glucose from biomass-based platform molecules. However, it remains difficult to develop high-activity and low-cost electrocatalysts toward GOR. Herein, we report a NiCoSex nanoplate supported on Ni foam with excellent activity for GOR electrocatalysis, which achieves a high current density of 500 mA cm-2 at 1.41 V vs reversible hydrogen electrode (RHE) and a 70.2% Faraday efficiency of formate at 1.40 V vs RHE. The surface component evolution of NiCoSex is studied by an in situ Raman spectrum, which points out the catalytic active species to be CoOx/CoOOH and NiOOH. Furthermore, we develop a two-electrode cell by pairing GOR with hydrogen evolution reaction using the NiCoSex electrode as the bifunctional catalyst for the anode and the cathode, which only requires an applied voltage of 1.50 V to reach a high current density of 200 mA cm-2 and retains long-term stability over 18 h with a high Faraday efficiency of H2 (close to 100%) in the cathode.

Glucose Electrocatalysis of Multi-walled Carbon Nanotubes/Polyvinyl Alcohol Conducting Hydrogel Composite Platinum Electrode

A porous conductive hydrogel electrode film of multi-walled carbon nanotubes (MWCNTs)/polyvinyl alcohol (PVA) was prepared by electrophoretic deposition technology, and the selective catalytic ability of MWCNTs/PVA on glucose was verified by cyclic voltammetry and open-circuit voltage. The electrochemical and physicochemical properties of MWCNTs/PVA porous conductive hydrogel electrode films were also characterized. The synergistic catalytic effects of MWCNTs/PVA porous conductive hydrogel electrode films and platinum electrode on the electrochemical oxidation of glucose in different PH solutions were studied.

Preparation of amorphous Ni/Co bimetallic nanoparticles to enhance the electrochemical sensing of glucose

Based on the incidence of diabetes, developing glucose sensors of superior performance with low-cost transition metals (TMs) has been the direction of many researchers, amorphous TMs with highly efficient electrocatalytic properties have attracted our interest. On this basis, amorphous nickel–cobalt bimetallic N-doped carbon nanoparticles on carbon cloth (a-Ni2/Co1-NC/CC) were fabricated from ZIF-8, which was then used to fabricate an enzyme-free glucose sensor. It was found that the a-Ni2/Co1-NC/CC had the best response to glucose in 0.4 M NaOH at 0.55 V (vs Hg/HgO). As compared to crystal Ni2/Co1 nanoparticle on carbon cloth (c-Ni2/Co1 NPs/CC), cyclic voltammetry (CV) and chronoamperometry studies revealed that the a-Ni2/Co1-NC/CC showed a significant increase in the efficient of electrochemical oxidation of glucose under optimal conditions, exhibiting a high sensitivity of 2.455 mA mM−1 cm−2 with a low detection limit of 0.15 μM (S/N = 3). Furthermore, the constructed sensor based on a-Ni2/Co1-NC/CC also has long-term stability and can be used to detect glucose accurately in beverages (pure milk, coffee drinks, tea drinks, and soda water) with reasonable recovery from 95.6 % to 105.6 %. This study provides a simple and feasible method for the construction of a highly sensitive non-enzyme glucose electrochemical sensor based on amorphous TMs.

One-pot preparation of NiMn layered double hydroxide-MOF material for highly sensitive electrochemical sensing of glucose

To rationally design and construct electrocatalytic nanomaterials is crucial for improving the sensitivity and selectivity of non-enzyme-based electrochemical sensors. Here, NiMn layered double hydroxide (LDH)-based MOF (NiMn-LDH-MOF) material was used as electrochemical electrode for highly sensitive assay of glucose. The NiMn-LDH-MOF was firstly synthesized by one-pot method via directly blending MOF-74, metal nodes and ammonia. The obtained NiMn-LDH-MOF has an excellent electrocatalytic activity for electrochemical oxidation of glucose and the NiMn-LDH-MOF/GCE sensor exhibits a wide linear detection range from 4.9 μM to 2.2 mM, a low detection limit (0.87 μM, S/N = 3), and high sensitivity (0.849 mA mM−1 cm−2). Meanwhile, the sensor has good selectivity and reliability for glucose detection in actual serum samples, suggesting the potential applicability of the sensor for glucose detection. The more exposed active sites, the introduction of LDHs subunit and the synergistic effect between Ni and Mn in the NiMn-LDH-MOF are the major factors to enhance the assay performance.

Constructing heterointerface of crystalline Au nanoparticles and amorphous porous CoSnO3 nanocubes for sensitive electrochemical detection of glucose

Au/CoSnO3 was explored as a novel electrocatalyst for highly sensitive nonenzymatic detection of glucose. Au/CoSnO3 was synthesized by a galvanic replacement strategy. The obtained nanomaterials were characterized by transmission electron microscopy (TEM), energy-dispersive X-ray spectrometry (EDS), X-ray diffractometry (XRD) and electrochemical techniques. The results display that a small amount of crystalline Au nanoparticles are decorated on the surface of amorphous porous CoSnO3 nanocubes. The formation of such unique amorphous/crystalline heterogeneous interface makes Au/CoSnO3 exhibit excellent electrocatalytic activity for the electrochemical oxidation of glucose. The sensor based on Au/CoSnO3 can detect glucose with a wide linear detection range of 0.2 µM–0.11 mM, a high sensitivity of 2317.1 µA·mM−1·cm−2 and a low detection limit of 0.078 µM. This study demonstrates CoSnO3 as an effective sensing material and also provides a way to improve electrocatalytic properties of nanomaterials through interfacial engineering.

Electrochemical fabrication of Co(OH)2 nanoparticles decorated carbon cloth for non-enzymatic glucose and uric acid detection.

Cobalt hydroxide nanoparticles (Co(OH)2 NPs) were uniformly deposited on flexible carbon cloth substrate (Co(OH)2@CC) rapidly by a facile one-step electrodeposition, which can act as an enzyme-free glucose and uric acid sensor in an alkaline electrolyte. Compositional and morphological characterization were examined by X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS), which confirmed the deposited nanospheres were Co(OH)2 nanoparticles (NPs). The electrochemical oxidation of glucose and uric acid at Co(OH)2@CC electrode was investigated by electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), differential pulse voltammetry (DPV), and chronoamperometry methods. The results revealed a remarkable electrocatalytic activity toward the single and simultaneous determination of glucose and uric acid at about 0.6 V and 0.3V (vs. Ag/AgCl), respectively, which isattributed to a noticeable synergy effect between Co(OH)2 NPs and CC with good repeatability, satisfactory reproducibility, considerable long-term stability, superior selectivity, outstanding sensitivity, and wide linear detection range from 1 uM to 2mM and 25nM to 1.5 uM for glucose and UA, respectively. The detection limits were 0.36nM for UA and 0.24μM for glucose (S/N = 3). Finally, theCo(OH)2@CC electrode was utilized for glucose and uric acid determination in human blood samples and satisfying results were obtained. The relative standard derivations (RSDs) for glucose and UA were in the range 6 to 14% and 0 to 3%, respectively. The recovery ranges for glucose an UA were 97 to 103% and 95 and 101%, respectively. These features make the novel Co(OH)2@CC sensor developed by a low-cost, efficient, and eco-friendly preparation method apotentially practical candidate for application to biosensors.

Ni-Coated Diamond-like Carbon-Modified TiO2 Nanotube Composite Electrode for Electrocatalytic Glucose Oxidation.

In this paper, a Ni and diamond-like carbon (DLC)-modified TiO2 nanotube composite electrode was prepared as a glucose sensor using a combination of an anodizing process, electrodeposition, and magnetron sputtering. The composition and morphology of the electrodes were analyzed by a scanning electron microscope and energy dispersive X-ray detector, and the electrochemical glucose oxidation performance of the electrodes was evaluated by cyclic voltammetry and chronoamperometry. The results show that the Ni-coated DLC-modified TiO2 electrode has better electrocatalytic oxidation performance for glucose than pure TiO2 and electrodeposited Ni on a TiO2 electrode, which can be attributed to the synergistic effect between Ni and carbon. The glucose test results indicate a good linear correlation in a glucose concentration range of 0.99–22.97 mM, with a sensitivity of 1063.78 μA·mM−1·cm−2 and a detection limit of 0.53 μM. The results suggest that the obtained Ni-DLC/TiO2 electrode has great application potential in the field of non-enzymatic glucose sensors.

Nitrogen-Containing Graphene for Electrochemical Sensing of Glucose

N-containing graphene was an excellent candidate for sensing and biosensing because of its comparable atomic radius with that of carbon and the formation of strong bonds. Its presence influenced the atomic charge distribution on the graphene scaffold, thereby enhancing the electrochemical activity. Here, nitrogen-containing graphene (N-graphene) prepared from papaya seeds was used to fabricate the electrode for the electrochemical oxidation of glucose using cyclic voltammetry and amperometry studies. The fabricated electrode showed a good response (6s) towards electrochemical oxidation of glucose with a linear range of 50-800 mg/L (R2=0.99369), the sensitivity of ~ 10.888 μAM−1cm−2 along with a detection limit of 0.9 μM. It efficiently determined the glucose concentration in three real samples (apple juice, coco-cola, and honey), which were found to be 2.06%, 4.21%, and 41%, respectively. Moreover, the electrode exhibited an acceptable reproducibility (RSD 7.6%), and the stability was observed as 82..6% of the initial value up to 15 days.

Low-Denaturazing Glucose Oxidase Immobilization onto Graphite Electrodes by Incubation in Chitosan Solutions

In this work, glucose oxidase (GOx) has been immobilized onto graphite rod electrodes through an assisted-chitosan adsorption reaching an enzyme coverage of 4 nmol/cm2. The direct and irreversible single adsorption of the Flavine Adenine Dinucleotide (FAD) cofactor has been minimized by electrode incubation in a chitosan (CH) solution containing the enzyme GOx. Chitosan keeps the enzyme structure and conformation due to electrostatic interactions preventing FAD dissociation from the protein envelope. Using chitosan, both the redox cofactor FAD and the protein envelope remain in the active form as demonstrated by the electrochemistry studies and the enzymatic activity in the electrochemical oxidation of glucose up to a concentration of 20 mM. The application of the modified electrodes for energy harvesting delivered a power density of 119 µW/cm2 with a cell voltage of 0.3 V. Thus, chitosan presents a stabilizing effect for the enzyme conformation promoted by the confinement effect in the chitosan solution by electrostatic interactions. Additionally, it facilitated the electron transfer from the enzyme to the electrode due to the presence of embedded chitosan in the enzyme structure acting as an electrical wiring between the electrode and the enzyme (electron transfer rate constant 2.2 s−1). This method involves advantages compared with previously reported chitosan immobilization methods, not only due to good stability of the enzyme, but also to the simplicity of the procedure that can be carried out even for not qualified technicians which enable their easy implementation in industry.

High performance of non-enzymatic glucose biosensors based on the design of microstructure of Ni2P/Cu3P nanocomposites

The transition-metal phosphides with metalloid characterics, exhibiting great application potential in the field of glucose detection that plays an important role in the treatment of diabetes, can achieve high sensitivity as a eletrocatalyst for nonenzymatic glucose sensors. However, it has the drawbacks of low detection range and difficulty in manufacture. In this work, a hybrid heterogeneous nanocomposite of copper and nickel phosphide (Ni2P-Cu3P) has been designed and successfully prepared by a mild one-step solvothermal method. Inspired by the porous characteristic of sponges, the mesoporous structure with a much larger surface area has been constructed by adjusting the reaction conditions and the element composition of copper and nickel to have more active sites, thus broadening linear range. The precisely designed heterogeneous nanostructure and the unique mesoporous morphology of Ni2P-Cu3P were confirmed and characterized by the XRD and TEM analysis. Electrochemical oxidation of glucose on the composite modified glassy-carbon electrode (Ni2P-Cu3P/GCE) was measured by chronoamperometry and cyclic voltammetry. At the optimal test potential of + 0.64 V, the Ni2P-Cu3P/GCE hybrid electrode possessed an ultra-high sensitive response of 4700 μA mM−1 cm−2 to glucose, in a broad linear range from 4 μM to 5 mM, and a low detection limit of 0.1 μM at an S/N ratio of 3. The electrode also exhibits excellent anti-interference properties towards other common co-existing electroactive distractions, such as ascorbic acid, uric acid, urea, dopamine, etc.

One-Step Hydrothermal Synthesis of CuO Micro-Crystals for Non-Enzymatic Glucose Sensors

CuO micro-crystals have been synthesized by a one-step, large-scale and environment-friendly hydrothermal route. The crystalline structure, morphology, valence state and elemental composition of the CuO micro-crystals were analyzed using different technologies. Cyclic voltammetry and chronoamperometry were studied to probe the electrochemical glucose oxidation properties of the CuO electrode, revealing excellent electrocatalytic performance with fast response time, low detection limit and applicable linear detection range. In addition, it shows good selectivity to glucose when there are interferences coexisting in the human blood. All these results imply the potential application of the sample as electrode materials of non-enzymatic glucose sensors.

Electrodeposited CuO thin film for wide linear range photoelectrochemical glucose sensing

Cupric oxide (CuO) has been used as a non-enzymatic glucose sensor for decades. However, there is a paucity of publications on bare CuO-based photo electrochemical (PEC) glucose detection. In this study, a photo active CuO thin film was electrodeposited onto conductive glass and its band gap was tuned by etching in NH3 solution. A 6 W light-emitting diode (LED) bulb was used as the light source for PEC glucose oxidation. Various physical and electrochemical characterization techniques were used to study the PEC behavior of the CuO thin film electrode during glucose oxidation. The electrochemical oxidation of glucose was found to be an irreversible electron transfer process controlled by diffusion at the electrode surface under illumination and dark conditions. Electrochemical impedance spectroscopy (EIS) confirmed that the charge transfer resistance in the light decreases by several orders of magnitude. Good amperometric performance was obtained for the CuO film with a 4 s response time and negligible interference from other species present in human blood. The as prepared sensor exhibited a remarkable wide linear range up-to 29 mM.