Non-enzymatic Amperometric Glucose Sensor Research Articles

Study of the application of a Cu2O thin film as non-enzymatic amperometric glucose sensor

The detection and control of glucose (Glu) levels in both food and biological samples have gained importance in recent decades, as imbalances in glucose levels can lead to health complications such as diabetes mellitus. Consequently, this study focused on synthesizing thin films of Cu2O and evaluating their application as a non-enzymatic amperometric glucose sensor. The Cu2O films were obtained on FTO at a constant potential (−0.575 V vs. SMSE), in an inert atmosphere and at room temperature. The electrolyte solution consisted of 0.02 M of copper acetate (Cu(OOCCH3)2) and 0.1 M of sodium acetate (NaOOCCH3) at pH 5.79, in a three-electrode cell. The films obtained were analyzed by scanning electron microscopy (SEM) and X-ray diffraction (XRD). On the other hand, the electrocatalytic activity was studied using linear potential sweep (LPS) and chronoamperometry (CA) techniques. From these techniques, it was possible to determine the sensitivity (228.1 µA mM−1 cm−2), limit of detection (LOD 2.49 x 10-3 mM), limit of quantification (LOQ 7.54 x 10-3 mM) and linear range (0.10 mM≤[Glucose] ≤ 15 mM). In this concentration interval the response time was between 1.4 and 14 s. It was established that the sensor exhibits minimal response to various electroactive interferences and demonstrates reproducibility and stability over time. In this way, the proposed Cu2O electrode is a good candidate to be used as a non-enzymatic amperometric glucose sensor.

Integrating Cu/CuxO ternary nanocomposites with multi-walled carbon nanotubes enabling a high-performance nonenzymatic amperometric glucose sensor

We developed a new nonenzymatic amperometric glucose sensor by integrating a ternary nanocomposite, Cu/Cu2O/CuO (Cu/CuxO), with multi-wall carbon nanotubes (Cu/CuxO@MWCNTs) as the electrocatalyst. The Cu/CuxO@MWCNTs nanocomposite is prepared via an electroless plating process followed by thermal treatment. The constructed nanocomposites are systematically characterized with a transmission electron microscope, an X-ray diffractometer, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and electrochemical impedance spectroscopy, respectively. The Cu/CuxO@MWCNTs nanocomposites-modified glassy carbon electrodes exhibit high electrocatalytic activity toward glucose electrooxidation under alkaline conditions. The efficient electrocatalytic activity of Cu/CuxO@MWCNTs for glucose electrooxidation is utilized for glucose detection using Cu/CuxO@MWCNTs-modified glassy carbon electrodes. The Cu/CuxO@MWCNTs-modified electrode displays an excellent sensing performance within a wide analyte concentration from 0.005-6,000 M (low detection limit is calculated to be 0.003 μM) with superior stability, selectivity, repeatability, and reproductivity. This as-prepared electrochemical sensor is successfully applied to selective glucose detection with satisfactory results.

Non-enzymatic amperometric glucose sensor based on bimetal-oxide modified carbon fiber ultra-microelectrode

In this study, an efficient non-enzymatic glucose sensor is proposed based on a bimetal-oxide-modified carbon fiber microelectrode (CFME). The NiO-CuO/CFME nanocomposite was synthesized by consecutive electro-deposition of CuO and NiO nanoparticles on the CFME. The morphology and structure of NiCuCFME were studied with scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX). NiCuCFME provides both a large surface area and electrocatalytic properties to improve electrochemical reactivity toward glucose oxidation. The electrocatalytic behavior of the sensing microelectrode is analyzed with cyclic voltammetry (CV) and amperometric techniques in an alkaline medium. The fabricated glucose microsensor exhibits a linear range from 1.32 μM to 570 μM, a sensitivity of 0.07 mA μM−1 cm−2, and a low limit of detection of 0.40 μM. The NiCuCFME shows long-term stability, good reproducibility, favorable repeatability, excellent selectivity, and satisfactory applicability for glucose detection which is a promising candidate for the development of non-enzymatic glucose sensors.

Development of an electrochemical nanoplatform for non-enzymatic glucose sensing based on Cu/ZnO nanocomposite

A non-enzymatic amperometric glucose sensor was designed based on Zinc Oxide (ZnO) and copper (Cu) composite membrane. The Copper/Zinc Oxide nanocomposite (Cu/ZnO NC) was elaborated by sol-gel technique, which was then characterized for physico-chemical properties using characterization techniques such as UV–Visible, X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and energy-dispersive X-ray spectroscopy analysis (EDXS). For the sensing electrode fabrication, the synthesized NC was deposited on Glassy Carbon Electrode (GCE) by drop-coating method. The electrochemical behavior of the elaborated sensor was studied through cyclic voltammetry (CV) and chronoamperometry (CA). The Cu/ZnO modified GCE possesses favorable electrocatalytic (EC) properties for the oxidation of glucose in alkaline solution. Furthermore, the suggested sensing nanoplatform for glucose determination had 2 linear ranges: 0.01 mM–1 mM and 1 mM–7 mM, good sensitivity (36.641 μA mM−1cm−2), a limit of detection (LOD) of about 57 μM, good selectivity as well as a response time of about 8 s. The findings of this study contribute to the applicability of a high-performance non-enzymatic glucose sensor and may potentially act as a significant alternative method for glucose analysis.

Facile preparation of a highly sensitive non-enzymatic glucose sensor based on the composite of Cu(OH)2 nanotubes arrays and conductive polypyrrole

A novel amperometric non-enzymatic glucose sensor is designed by the facile preparation method. It is made by electrodeposition of Cu clusters and converting them to Cu(OH)2 nanotubes (Cu(OH)2NTs) arrays along with thin-film electro-polymerized of spindle-shaped polypyrrole (PPy@Cu(OH)2NTs), which have been doped by using sodium Benzene-1,3-disulfonate as an anion dopant. Various electrochemical methods investigate the electrochemical performance of the modified electrode toward glucose detection. Under the optimized conditions, a significant electrochemical response improvement is observed toward the electro-oxidation of glucose on the PPy@Cu(OH)2NTs electrode's surface relative to the Cu(OH)2NTs and the bare glassy carbon electrode. The designed electrode demonstrated an acceptable linear dynamic range in two wide ranges of 0.001 mM–1.78 mM and 1.78 mM–6.53 mM with high sensitivity of 910 µA mM−1 cm−2 and 675 µA mM−1 cm−2, respectively. The results are shown a low detection limit of 0.35 µM. Besides high sensitivity, this sensor represented good reproducibility and repeatability for glucose analysis and also provided relevant results for the non-enzymatic glucose determination in clinical preparations. This system also exhibits high selectivity for glucose oxidation that almost no signal was detected from interferences such as ascorbic acid, dopamine, uric acid, and chloride ions, demonstrating its great potential as a non-enzymatic glucose sensor. The superb sensing performance is ascribed to the sufficient catalytic sites of scroll-like Cu(OH)2NTs arrays morphology and synergistic effect of the doped-polypyrrole, which improve the surface area and act as a conductive binder on the electrode surface.

Cover Feature: Lamellar FeOcPc‐Ni/GO Composite‐Based Enzymeless Glucose Sensor (ChemElectroChem 12/2020)

The Cover Feature illustrates the nanocomposite material FeOcPc−Ni/GO made of stacked graphene oxide sheets covered with carboxylated iron phthalocyanine molecules connected through ultra-small nickel hydroxide nanoparticles, providing a very effective electrocatalyst for glucose sensing based on its oxidation to gluconic acid in aqueous media. Reproducible, high signal-to-noise ratio responses were achieved at potentials as low as +0.5 V (at the right side), realizing a sensitive and robust amperometric non-enzymatic glucose sensor as a consequence of synergic effects, as evaluated by batch injection analysis (BIA). More information can be found in the Article by B. N. Safadi et al.

CuO/MoS2 nanocomposites for rapid and high sensitive non-enzymatic glucose sensors

Non-enzymatic amperometric glucose sensor is fabricated using CuO/MoS2 nanocomposites (CuO/M) by a facile method with high sensitivity. Cyclic Voltammetry (CV) studies of nanocomposites reveal the strong electrocatalytic activity for a wide range of glucose concentrations (0.1–10 mM) with a high current response in 0.1 M NaOH solution. The CuO/M modified electrode sensor shows high sensitivity (1055 μA/mM.cm2), rapid response (<2s), and lower detection limit (0.017 μμM) in the linear range of 35 μM–800 μM. The synergistic effect of MoS2 and CuO resulted in improved glucose electro-oxidation in alkaline solution. From the experimental results, it is inferred that modification with MoS2 could be a potential strategy to enhance the electrocatalytic properties of low-cost metal oxides.

Non-Enzymatic Amperometric Glucose Sensor Based on Carbon Nanodots and Copper Oxide Nanocomposites Electrode.

In this research work, a non-enzymatic amperometric sensor for the determination of glucose was designed based on carbon nanodots (C-dots) and copper oxide (CuO) nanocomposites (CuO-C-dots). The CuO-C-dots nanocomposites were modified on the surface of a screen-printed carbon electrode (SPCE) to increase the sensitivity and selectivity of the glucose sensor. The as-synthesized materials were further analyzed for physico-chemical properties through characterization tools such as transmission electron microscopy (TEM) and Fourier-transform infrared spectroscopy (FTIR); and their electrochemical performance was also studied. The SPCE modified with CuO-C-dots possess desirable electrocatalytic properties for glucose oxidation in alkaline solutions. Moreover, the proposed sensing platform exhibited a linear range of 0.5 to 2 and 2 to 5 mM for glucose detection with high sensitivity (110 and 63.3 µA mM−1cm−2), and good selectivity and stability; and could potentially serve as an effective alternative method of glucose detection.

Macro-/meso-porous NiCo2O4 synthesized by template-free solution combustion to enhance the performance of a nonenzymatic amperometric glucose sensor.

A sensitive nonenzymatic amperometric glucose sensor is described thatrelies on a glassy carbon electrode modified with a macro-/meso-porous NiCo2O4. NiCo2O4 with spinel structure has been prepared via a one-step solution combustion method. The material was characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and nitrogen absorption/desorption. An electrode was coated with the porous material and then displayed excellent electrocatalytic activity towards the direct oxidation of glucose in 0.15M NaOH solution by cyclic voltammetry. Amperometric I-t curve demonstrated a sensitivity of 2100μA·mM-1·cm-2 at an applied potential of 0.45V (vs Hg/HgCl). The sensor has a linear response in the 0.001 to 1.0 mΜ glucose concentration range, a fast response time (3.9s) and a low detection limit (0.38 μΜ). Graphical abstract.

NiO nanoparticles -decorated conductive polyaniline nanosheets for amperometric glucose biosensor

At present tuneable properties and morphology of polymer composites have become fundamental forefront research interest in sensing applications. Using existing approaches with a new idea, this paper reports the synthesis of Polyaniline nanosheets (PANINS) with surface modification by nickel oxide nanoparticles (NiO) through in situ polymerization. The morphology and presence of functional groups of as obtained NiO-NPs @PANINS witnessed the formation of the thin surface of PANINS decorated by NiO-NPs using FESEM, TEM, and FTIR. The structural analysis of as prepared NiO-NPs and NiO-NPs@PANINS confirmed the crystallinity by insignificant stacking fault, dislocation density, and microstrain. Furthermore, the synthesized NiO and NiO@PANINS were used as a modified screen-printed electrode (SPE) for the fabrication of electrochemical non-enzymatic glucose sensor. The invented sensor used for amperometric non-enzymatic glucose sensor exhibited a high sensitivity of 5625 μA mM−1 cm−2, and low detection limit 0.06 μM. Besides that, the interference study shows excellent selectivity and also retains good stability. We believe that this NIO@PANINS nanocomposite could be utilized as low cost, an eco-friendly efficient electrode for the electrochemical biological sensor.

A non-enzymatic amperometric glucose sensor based on the use of graphene frameworks-promoted ultrafine platinum nanoparticles.

Ultrafine platinum nanoparticles are grown on a 3D graphene framework (GF-Pt) via a hydrothermal method. The material, when placed on a glassy carbon electrode (GCE), displays enhanced electrocatalytic activity towards glucose oxidation. This is assumed to be the result of the numerous easily accessible active sites, an enlarged electrochemically active area, and the presence of multiple electron/ion transport channels. The modified GCE can be operated at a low potential (- 0.15V vs. Ag/AgCl) has linear responses in the 0.1μM - 0.01mM and 0.01mM-20mM glucose concentration range, and a 30nM detection limit. It was applied to the rapid determination of glucose in human serum samples. Graphical abstract Schematic presentation of a glassy carbon electrode modified with ultrafine Pt nanoparticles grown on a graphene framework (GFs-Pt). GFs-Pt presents enhanced electrocatalytic activity towards glucose oxidation. GFs-Pt is used in a sensitive non-enzymatic amperometric glucose sensor.

Green method for glucose determination using microfluidic device with a non-enzymatic sensor based on nickel oxyhydroxide supported at activated biochar

This paper reports the use of nickel ions supported at activated biochar carbon paste electrode (NiAB-CPME) coupled in a microfluidic thread-based electroanalytical device (μTED) for non-enzymatic glucose determination. Biochar was initially prepared from castor oil cake at 400 °C and activated by HNO3 refluxing. Activation process promoted an increase of functional groups, surface area and porosity in comparison to precursor biochar. Activated biochar (AB) has shown an excellent performance to spontaneous preconcentration of Ni(II) ions. In alkaline conditions a stable voltammetric profile associated to Ni(OH)2/NiOOH redox pair was verified and a significant catalytic effect was observed in presence of glucose which was used for its monitoring. Microfluidic device was assembled at a plastic platform printed using 3D printer being easy to construction using low cost materials. Non-enzymatic amperometric glucose sensor coupled in μTED showed a good repeatability of 3.84% for successive injections of glucose (n = 10), a constant flow rate of 1.11 µL s−1 and an analytical frequency of 61 injections per hour. A linear dynamic range (LDR) from 5.0 to 100.0 µmol L−1, limit of detection (LOD) of 0.137 µmol L−1 and limit of quantification (LOQ) 0.457 µmol L−1 glucose were obtained. The proposed device was applied to glucose determination in real biological samples of human saliva and blood serum. Finally, the method was considered a green analytical procedure with Eco-Scale score of 81.

New route for the synthesis of nickel (II) oxide nanostructures and its application as non-enzymatic glucose sensor

Sonoelectrochemistry is a technique that allows studying the effects of ultrasonic radiation on electrochemical systems. This technique is clean, inexpensive, improves the activation of the electrode surface and enables short synthesis times. In this context, this study uses sonoelectrochemistry to produce nickel oxide nanostructures, which will be proposed as an efficient and reliable glucose sensing device enzyme-free. For this, nickel oxide nanostructures have been electrochemically grown by ultrasound-assisted anodization of nickel foils in a solution composed of: ethylene glycol, ammonium chloride (0.5wt% of NH4Cl) and 5.0wt% of H2O solution. The anodization experiments were carried out using ultrasonic waves (37kHz, 60W) at different potentials (50 and 75V), different temperatures (50°C and 75°C) and 900s as anodization time. The process was carried out using a two-electrode system. The nanostructured NiO layers obtained were analyzed SEM, XRD and EDX for morphology, crystalline structure and chemical composition, respectively. The electrocatalytic activity of nanostructured NiO in the glucose oxidation reaction was studied by linear sweep voltammetry (LSV). From this technique, it was possible to determine the kinetic parameters that allow proposing a mechanism by which the glucose oxidation process takes place. The sensitivity (206.9μAmM−1cm−2), the limit of detection (LOD, 1.16μM), the limit of quantification (LOQ, 3.87μM), the linear working range of the proposed electrode (0.1mM≤[Glucose]≤10mM) and the response time (6s), were determined. Finally, it was established that the nanostructured NiO electrode doesn't respond to different interferences (e.g. ascorbic, uric acid and dopamine acid), confirming the selectivity of NiO nanostructures for glucose. So, the electrode proposed in this study, is a good candidate for to be used as a non-enzymatic amperometric glucose sensor due to the good merit figures and its simple synthesis by ultrasound-assisted anodization.

Amperometric Enzyme-Free Glucose Sensor Based on Electrodeposition of Au Particles on Polyaniline Film Modified Pt Electrode

An amperometric non-enzymatic glucose sensor of high sensitivity was developed by modification of Pt electrode with electrodeposition of Au particles on polyaniline film. The Au particles were deposited under optimum growth conditions for maximum dispersion on polymer film to achieve highly sensitive glucose sensor. The characterization of the electrode and the analytical parameters were evaluated using chronoamperometry and cyclic voltammetry techniques. The sensor showed wide linear range from 0.01-8 mM along with swift response time of less than 5 s. Moreover, a high sensitivity of 113.6 ∆A mM-1 cm-2 is obtained along with low detection limits of 0.5 ∆M. The sensor also showed high stability, reproducibility and repeatability. Furthermore, the sensor has shown high selectivity towards glucose exclusively in the presence of interferents such as sucrose, uric acid, and ascorbic acid. The practical applicability of the proposed sensor was confirmed from successful analysis of glucose in different juice samples and these results were comparable to the commercial glucose meter. Thus, our sensor stands promising non-enzymatic sensor for routine analysis of glucose.

Highly-branched dendrite cuprous oxide films for non-enzymatic amperometric glucose sensor

Cuprous oxide (Cu2O) thin films with highly-branched dendrite structures were synthesized by electroplating through a simple stirring condition. And, the improved performance of glucose oxidation was achieved on the dendrite Cu2O film electrode. For the amperometric glucose detection, a favorable performance with a high sensitivity of 1470.8467 µA mM−1 cm−2 and a low operating potential of 0.50 V were achieved. Thus, it would be a promising candidate electrode material for the development of non-enzymatic glucose sensors.

Novel One Pot Synthesis of Alkaline-reduced Iron Oxide/graphene Nanocomposites for Amperometric Non-enzymatic Glucose Sensor

Novel One Pot Synthesis of Alkaline-reduced Iron Oxide/graphene Nanocomposites for Amperometric Non-enzymatic Glucose Sensor

Nonenzymatic determination of glucose at near neutral pH valuesbased on the use ofnafion and platinum black coated microneedle electrode array.

The authors report on a microneedle-based amperometric nonenzymatic glucose sensor for painless and continuous monitoring of glucose. It consists of 3 × 5 sharp stainless steel microneedles micromachined from a stainless steel substrate. The microneedles are 600 and 100μm in height and width, respectively. Nafion and platinum black were sequentially coated onto the tip of gold-coated microneedles and used for nonenzymatic (direct) sensing of glucose. Attractive features of the modified microneedle electrode include (a) a low working potential (+0.12V vs. Ag/AgCl), (b) a linear response in the physiologically relevant range (1-40mM), (c) a sensitivity as high as 175μAmM-1cm-2, (d) a 23μM detection limit, and (e) a response time of 2s. The sensor also exhibits good reproducibility and stability. The sensor is selective for glucose even in the presence of 10-fold higher concentrations of ascorbic acid, lactic acid, dopamine, uric acid, and acetaminophen. Graphical abstract Schematic representation of the fabrication sequence for a nonenzymatic electrochemical glucose sensor using Nafion and platinumblack coated microneedle electrode array. The sensor is based on measuring the faradaic current at +0.12V vs. Ag/AgCl by the direct electrochemical oxidation of glucose to gluconic acid on the surface of aPt black sensing layer.

Well-dispersed poly(m-phenylenediamine)/silver composite for non-enzymatic amperometric glucose sensor applied in a special alkaline environment

A poly(m-phenylenediamine)/sliver (PmPD/Ag) composite electrode was fabricated by in situ generation of solver particles on the surface of poly(m-phenylenediamine) (PmPD) matrix, and its electrochemical and amperometric non-enzymatic sensor performances were studied under the different electrolytes. And the characteristics of PmPD/Ag composite were also measured by scanning electron microscopy (SEM), ultraviolet visible (UV-vis) absorption spectrum, Fourier transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA), respectively. The results of SEM indicated that the PmPD/Ag composite has been successfully prepared and the silver (Ag) particles were well dispersed on the surface of the PmPD matrix. And FTIR and UV-vis demonstrated that the introduction of Ag particles facilitated the charge transfer along the PmPD polymer chain, which is beneficial to the improvement of electrochemical performances. Furthermore, the electrochemical and sensor performances based on PmPD/Ag composite were investigated by cyclic voltammetry (CV) and amperometric i-t curve. The research results demonstrated that PmPD/Ag composite electrode in the alkaline environment showed an outstandingly electrochemical catalysis characteristic to glucose, such as a low detection limit of 7.2 μM, a wide linear range of 12.5 μM to 23.0 mM (R = 0.998), a short response time (within 3 s), and high sensitivity (1611.9 μA mM−1 cm−2) and stability (87% remains after 30 days). The constructed non-enzymatic sensor was one of the promising candidates due to its superior sensitivity, selectivity, and reproducibility.

A non-enzymatic glucose sensor based on CuO-nanostructure modified carbon ceramic electrode

Mesoporous silica-graphite composite (SiO2/C-graphite) was synthesized by the sol-gel technique. The surface area (SBET=98.93m2/g), pore volume (0.30cm3/g) and pore size (12.16nm) were characterized by BET. The novelty of this work lays in the fabrication of material in which ceramic material (SiO2/C-graphite) was decorated with copper oxide (CuO) nanostructure. SEM images revealed material compactness without phase segregation and EDX mapping showed a homogenous structure. Pressed disk electrode fabricated with SiO2/C/CuO nanocomposite material was evaluated as an amperometric non-enzymatic glucose sensor in 0.1M NaOH solution. The linear response range, sensitivity, detection limit, and quantification limit were 0.02–20.0mmolL−1, 0.06μmolL−1, 472μA mmol−1L−1cm−2, and 0.76mmolL−1, respectively. The electrode response time is <1s with the addition of 0.02mmolL−1 glucose. The electrode is chemically stable, exhibits rapid and excellent sensitivity and does not show any interference from coexisting species present in the blood samples. The proposed sensor repeatability was assessed as 1.9% RSD for ten measurements of 13.0mmolL−1 glucose solution. The sensor tested to ascertain glucose in blood serum showed to be a promising tool for the future evolution of non-enzymatic glucose sensors.

Flower-like MoS2 decorated with Cu2O nanoparticles for non-enzymatic amperometric sensing of glucose

In this study, a novel nanohybrid consisting of flower-like MoS2 decorated with Cu2O nanoparticles has been successfully synthesized for non-enzymatic amperometric sensing of glucose. Structural characterizations revealed that Cu2O nanoparticles were highly dispersed on MoS2 nanosheets. Electrochemical performances were investigated by cyclic voltammetry (CV) and chronoamperometry. Compared to single Cu2O component, the-synthesized Cu2O/MoS2 nanohybrid showed superior electrocatalysis to the oxidation of glucose. The fabricated non-enzymatic amperometric glucose sensor exhibited a wide linear range from 0.01 to 4.0mM with a low detection limit of 1.0µM (S/N =3) and a high sensitivity of 3108.87μAmM−1cm−2. Meanwhile, the non-enzymatic sensor also possesses satisfactory stability, good reproducibility and high selectivity to interfering components of uric acid, dopamine and ascorbic acid. The excellent analytical performances are resulted from the synergistic effect provided by the Cu2O nanoparticals and MoS2 nanosheets.