Sensitive Non-enzymatic Glucose Research Articles

Fabrication and Potential Characterization of Silver‐Doped Zinc Oxide Glucose Biosensor

This work is devoted to studying and manufacturing a highly sensitive nonenzymatic glucose biosensing system of metal oxides via the sol–gel technique. The X‐ray diffraction patterns of all the prepared samples confirm that the samples present hexagonal crystal lattice structures of ZnO and Ag–ZnO nanoparticles. Ultraviolet (UV) analysis of all the samples is carried out to evaluate the absorption of silver in the UV region for electrical and chronoamperometric analysis. The transmittance of all the samples is observed, and the maximum transmittance is 11% for 4% AgZnO. Fourier transform infrared spectroscopy reveal the functional group stretching and vibration of the particles at different wavelength ranges. Scanning electron microsocpy analysis reveals the grain size and morphology of the samples, which decrease with increasing doping agent. Chronoamperometric analysis of all the samples reveals that the value increases with time for the 4% doped sample. The sensing response is also observed and is enhanced with increasing temperature for the 4% doped sample. The sensing response of the samples coated with carbon fiber electrodes is assessed from −0.2 to +0.5 V at a scan rate of 50 mV s−1.

One‐Pot Carbothermal Reduction Preparation of Cu‐BTC@Cu/C Heterostructure for Enhanced Nonenzymatic Electrochemical Glucose Sensing

AbstractA heterostructure based on MOFs with a small lattice mismatch is ideal for improving glucose‘s electrochemical sensing performance. Herein, a novel one‐pot carbothermal reduction technique to prepare Cu‐BTC@Cu/C heterostructure with intimate interfacial contact and high yield was developed, by in situ integrating Cu‐BTC (Cu3(BTC)2 ⋅ 3H2O) and its derived Cu/C nanocomposites. Structure characterizations demonstrated that Cu‐BTC@Cu/C heterostructure shows a synergistic effect in the combination of these two components, with more electrochemical active sites and lower resistance. Compared with each individual component, Cu‐BTC@Cu/C heterostructure exhibits better glucose electrooxidation performance. Under optimal condition, an extremely sensitive nonenzymatic glucose sensor with a low detection limit of 6.78 μM, sensitivity of 911.03 μA mM−1 cm−2, linear range of 0.001–2.0 mM, and anti‐interference performance is presented. Meanwhile, the newly constructed sensor was effectively employed for detecting glucose in honey sample with perfect recoveries, showing its great potential toward glucose monitoring in real sample. In addition, it has been demonstrated Cu(II) can be induced into Cu(I) by glucose in solution, while Cu(I) could be electrochemically converted to Cu(II), therefore achieving a Cu(I)/Cu(II) redox cycle. It offers a promising strategy for synthesis of advanced electrocatalysts with high efficiency and promising applications in this paper.

Conformal sulfidation of HKUST-1 for constructing porous Cu2S/CuO octahedrons realizing highly sensitive non-enzymatic glucose detection

Metal–organic frameworks (MOFs) are believed to be promising precursors for constructing novel and efficient catalysts for glucose sensing. Herein, HKUST-1 precursors are first fabricated using a one-pot hydrothermal approach, and then HKUST-1 is converted into porous Cu2S/CuO octahedrons through conformal sulfidation with the help of OH− ions. The as-obtained Cu2S/CuO composite can provide rich electrochemical active sites and promoted electric transfer kinetics. Benefiting from these combined merits, the as-fabricated Cu2S/CuO composite is confirmed to be a high-performance catalyst, with high sensitivities of 8269.45 and 4140.82 μA mM−1cm−2 in the corresponding ranges of 0.05 ∼ 0.6 mM and 0.6 ∼ 1.2 mM, respectively. Moreover, the as-prepared electrode materials possess good anti-interference ability, reproducibility and long-term stability. This work opens up new avenues for the design and preparation of transition metal sulfide composites.

A novel strategy towards the fabrication of highly stable and sensitive non-enzymatic glucose sensor based on Ni3N thin films using high power impulse magnetron sputtering

Glucose level surveillance in mankind is considered the greatest need of recent times to achieve healthy lifestyle goals due to its health-related concern for humans. To fulfill the need, Nickel-based compounds emerge with excellent bio-mimic properties. However, due to the poor electrical properties of oxides and hydroxides of Ni, developing a supporting base that can enhance electron transportation is mandatory. The present work is dedicated to non-enzymatic glucose detection by electrochemical means on the Ni3N thin film on an Indium-doped Tin Oxide (ITO) substrate as a working electrode in an alkaline medium. The Ni3N films use HiPIMS as a deposition technique due to its high ionization rate of sputtered species and dense plasma which helps the Ni ions to react with nitrogen in the formation of a perfect Ni3N phase, and it is a green process that can contribute to sustainable manufacturing. Ni3N thin film deposited at a 60 % N2 flow ratio shows the largest crystallinity and catalytic properties, which helps this modified electrode to have significant potential for glucose detection. The Ni3N modified electrode acquires a lower linear range of 0.001–1.25 mM with sensitivity and Limit of Detection (LOD) of 337.46 µAmM–1cm−2, and 0.78 µM, respectively, and a higher linear range of 1.25–7.3161 mM with a sensitivity of 158.58 µAmM–1cm−2. The amperometric measurements reveal the fast response of the electrode towards glucose detection at 2.46 secs. The key measures of the electrode according to the corresponding measurements are satisfactory selectivity, reproducibility, repeatability, and operational stability. The modified electrode shows a significant response for real samples such as commercially available honey, apple juice, and biological fluids.

Green synthesized gold nanoparticles and CuO-based nonenzymatic sensor for saliva glucose monitoring.

Glucose, essential for brain and muscle functions, requires careful monitoring in diabetes and other chronic disease management. While blood glucose monitoring provides precise information about these diseases, it remains an invasive method. Saliva glucose monitoring could offer an alternative approach, but the glucose concentration in saliva is very low. In this work, we report a simple, low-cost, highly sensitive nonenzymatic electrochemical glucose sensor. We developed this sensor using green synthesized gold nanoparticles (AuNPs) and wet chemical synthesized copper oxide (CuO) nanoparticles on a screen-printed carbon electrode (Au/CuO/SPCE). The sensor's high sensitivity results from dual amplification strategies using AuNPs and CuO nanomaterials, each demonstrating catalytic activity towards glucose. This shows promising potential for saliva glucose monitoring. The AuNPs were synthesized using an Au precursor and orange peel extract (OPE), yielding stable colloidal AuNPs with a mean diameter of about 37 nm, thus eliminating the need for additional capping agents. Under optimal conditions, amperometric tests revealed that the sensor responded linearly to glucose concentrations ranging from 2 μM to 397 μM with a sensitivity of 236.70 μA mM-1 cm-2. Furthermore, the sensor demonstrated excellent reproducibility, stability and high selectivity for glucose in the presence of different biomolecules. We validated the sensor's efficacy by measuring glucose in human saliva, showing its potential for noninvasive glucose monitoring. This research advances the development of point-of-care devices, positioning the sensor as a promising tool for noninvasive glucose monitoring and improved diabetes management.

Facile preparation of a CoNiS/CF electrode by SILAR for a high sensitivity non-enzymatic glucose sensor.

The nanomaterials for non-enzymatic electrochemical sensors are usually pre-synthesized and coated onto electrodes by ex situ methods. In this work, amorphous cobalt-nickel sulfide (CoNiS) nanoparticles were facilely prepared on copper foam (CF) by the in situ successive ionic layer adsorption and reaction (SILAR) method, and as-prepared CoNiS/CF was studied as an electrode for non-enzymatic glucose sensing. It was analyzed by field emission scanning electron microscopy (FESEM), energy dispersive X-ray analysis (EDAX) and X-ray photoelectron spectroscopy (XPS). The electrochemical performance was investigated by cyclic voltammetry (CV) and chronoamperometry (CA). This binary sulfide electrode showed better performance toward glucose oxidation compared to the corresponding single sulfide and showed a wide linear range of 0.005 to 3.47 mM, a high sensitivity of 2298.7 μA mM-1 cm-2 and a low detection limit of 2.0 μM. The sensor exhibited high sensitivity and good repeatability and stability and was able to detect glucose in an actual sample. This work provides a simple and fast in situ electrode preparation method for a high-sensitivity glucose sensor.

One-Step Method for the Direct Growth of NiO Nanoflowers on Pencil Graphite Electrode for Highly Sensitive Non-Enzymatic Glucose Sensing

Electrochemical glucose sensors, including enzymatic and non-enzymatic sensors, have been considered as quick, accurate, and efficent means for glucose measurement. Recently, non-enzymatic electrochemical glucose sensor based on metal oxides have been paid attention to develop thank to their outstanding behaviours. In most of these studies, metal oxides were synthesized individually and subsequently deposited on the electrode surface using a binder. In this study, we aim at developing a non-enzymatic glucose sensor based on NiO nanoflowers directly grown on a commercial pencil graphite electrode. NiO matetials were deposited on the electrode without a binder via a facile and low-cost chemical procedure. The synthesised materials’ morphologies and components of were characterized by a field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray diffraction analyses. Electrocatalytic performance was recorded by cyclic voltammetry and chronoamperometry. The resulting NiO nanoflowers, characterized by funnel-shaped structures measuring 500–600 nm in diameter and 20 nm in thickness, were formed on the pencil graphite electrode. The fabricated electrode showed a remarkably high sensitivity of 337 μA mM−1 cm−2, a low limit of detection of 4 μM, and good selectivity. The fabricated electrode can be a potential candidate for clinically medical applications.

A Highly Sensitive Non-Enzymatic Glucose Electrochemical Sensor Electrode Material of CuO Nanospheres/Activated Carbon Composites

A Highly Sensitive Non-Enzymatic Glucose Electrochemical Sensor Electrode Material of CuO Nanospheres/Activated Carbon Composites

Screen-printed electrode modified with MoO3-MoS2/Ni porous array for sensitive non-enzymatic glucose sensor

A MoO3-MoS2/Ni porous micro/nano array was successfully prepared by two-step electrodeposition using a screen-printed electrode as the substrate and colloidal spheres as a template. Owing to defects in the MoO3-MoS2 micro/nanostructure and the characteristics of the edge active sites, the modified electrode performs well as a non-enzymatic glucose sensor. The sensitivity of the screen-printed electrode modified with MoO3-MoS2/Ni porous array is 2278 μA mM−1 cm−2 in the linear range of 0.5 μM–2 mM and 1421 μA mM−1 cm−2 in the linear range of 2–5.5 mM, with a low detection limit of 0.2 μM. The structure of the MoO3-MoS2/Ni porous array electrode is ordered, and the preparation and test procedure are simple. The use of a screen-printed electrode as a substrate confers novelty to the synthesis strategy of the non-enzymatic glucose sensor, with good prospects for commercial application.

In situ synthesis of self-supporting conductive CuCo-based bimetal organic framework for sensitive nonenzymatic glucose sensing in serum and beverage

Most MOFs are associated with the inherent defect of low conductivity, limiting their further application in electrochemical sensing. Herein, a self-supporting conductive CuCo-based bimetal organic framework with HHTP as the organic ligand was in situ synthesized on carbon cloth via a one-step hydrothermal method, namely CuCo-MOF/CC. Benefiting from the advantages of electrical conductivity and bimetallic synergies, CuCo-MOF/CC exhibited remarkable electrocatalytic performance toward glucose. Consequently, the prepared sensor demonstrated an outstanding sensitivity of 9317 μA mM−1 cm−2, a wide range of 0.25–2374.5 μM, a low determination limit (0.27 μM), and a rapid response time (1.6 s). The reproducibility, stability, and selectivity were also proved to be satisfactory. Furthermore, the remarkable feasibility of proposed sensor was confirmed in serum and beverages. With the convenience of the one-step hydrothermal method and portability of self-supporting electrode, CuCo-MOF/CC has emerged as a promising candidate for commercial glucose sensors.

Synthesis of unique three-dimensional CoMn2O4@Ni(OH)2 nanocages via Kirkendall effect for non-enzymatic glucose sensing

Transition metal oxides / hydroxides, which have the advantages of wide distribution, low price, low toxicity, and stable chemical properties, have attracted much attention from researchers. Therefore, this work reports the construction of the unique CoMn2O4 nanocages assisted by the Kirkendall effect, and worm-like Ni(OH)2 nanoparticles were grown on the surface via hydrothermal method, the final product CoMn2O4@Ni(OH)2 nanocages were applied to construct efficient and sensitive non-enzymatic glucose electrochemical sensing. The stable three-dimensional hollow CoMn2O4 nanocages structure, not only can provide a wider specific surface area and more abundant active sites, its porous structure also can effectively inhibit the aggregation of nanoparticles, increase the ion diffusion path, shorten the electron transport distance, and improve the electrical conductivity. Loading Ni(OH)2 nanoparticles on the CoMn2O4 nanocages can increase catalytic sites, and further strengthen the electrocatalytic performance. Due to the good synergistic effect between CoMn2O4 and Ni(OH)2, CoMn2O4@Ni(OH)2 nanocages electrochemical sensor can achieve sensitive and rapid detection of trace glucose, with excellent linear range (8.5–1830.5 μM), low limit of detection (0.264 μM), high sensitivity of 0.00646 μA mM−1 cm−2, and outstanding repeatability. More importantly, the sensor has been successfully applied to the determination of blood glucose in human serum with good recoveries (95.64–104.3 %). This work provides a novel scheme for blood glucose detection and expands the application of transition metal oxides / hydroxides in the field of electrochemical sensing.

Exploiting synergistic interaction in Cu-Zn-Ni alloy oxide films prepared by one-step anodizing for a highly sensitive non-enzymatic glucose sensor

A highly sensitive and precise electrochemical biosensor for glucose detection was developed by coupling synergetic catalysis of Cu-Zn-Ni oxide films. To enhance the catalytic performance of alloy, potentials between −0.5 V and 1.5 V are selected for potentiostatic oxidation. Notably, the oxidation process reveals the influence of Cl− in the electrolyte, leading to electrode surface etching, with increasing etching and grain boundary collapse at higher potentials. The electrochemical performance of the electrode was comprehensively evaluated using cyclic voltammetry (CV) and amperometric response in alkaline conditions. The catalytic electrode has an impressive linear response in the concentration range of 0.1 ∼ 1.0 mM glucose, with a sensitivity of 3775.11 μA·mM−1. Furthermore, the electrode exhibits remarkable stability and anti-interference properties, rendering it suitable for non-enzymatic glucose sensing applications.

Cu Aerogels with Sustainable Cu(I)/Cu(II) Redox Cycles for Sensitive Nonenzymatic Glucose Sensing.

Developing functional nanomaterials for nonenzymatic glucose electrochemical sensing platforms is vital and challenging from the perspective of pathology and physiology. Accurate identification of active sites and thorough investigation of catalytic mechanisms are critical prerequisites for the design of advanced catalysts for electrochemical sensing. Herein, Cu aerogels are synthesized as a model system for sensitive nonenzymatic glucose sensing. The resultant Cu aerogels exhibit good catalytic activity for glucose electrooxidation with high sensitivity and a low detection limit. Significantly, in situ electrochemical investigations and Raman characterizations reveal the catalytic mechanism of Cu-based nonenzymatic glucose sensing. During the electrocatalytic oxidation of glucose, Cu(I) is electrochemically oxidized to generate Cu(II), and the resultant Cu(II) is spontaneously reduced back to Cu(I) by glucose, achieving the sustained Cu(I)/Cu(II) redox cycles. This study provides profound insights into the catalytic mechanism for nonenzymatic glucose sensing, which provides great potential guidance for a rational design of advanced catalysts in the future.

Highly efficient and sensitive non-enzymatic glucose biosensor based on flower-shaped CuO-colloid nanoparticles decorated with graphene-modified nanocomposite electrode

In this work, copper nanoparticles were synthesized through the colloidal and solution combustion method, and their electrochemical properties were evaluated using three electrode systems to detect glucose content. The solution combustion method using the fuels glycine (Gly) and hydrazine (Hyd) produces nanoparticles with amorphous spherical forms and a small flake-like structure. The colloidal method yields Cu-Colloid nanoparticles that have a homogenous phase and a flower-like structure with high electro-oxidative current due to the large surface area of the developed nanoparticle which is in contact with the glucose. A glucose biosensor was then fabricated using the developed colloidal copper nanoparticles modified with graphene-coated on indium-coated tin oxide (ITO) glass substrate (Flower shaped-CuO/G/ITO) as a working electrode. The copper nanoparticles were characterized by an X-ray diffractometer, UV–VIS spectrometer, Transmission, and Scanning electron microscope for crystalline, morphological, surface studies with 10–20 nm in diameter, 280–310 nm absorption range, and energy bandgap of 1.45ev. The lower detection limit of 1 μmol L−1, the sensitivity of 1610 μA mM−1 cm−2, and the linear range of 1 μMto μ850 M at an applied potential of +0.60 V vs. Ag/AgCl was obtained for the developed nanocomposite electrode. The developed bioelectrode shows good stability and reproducibility with less response time making it a promising electrode for developing a non-enzymatic glucose biosensor.

Au-wrapped CuS-Interlaced Chain Structure for Ultrafast Response and High Sensitive Non-Enzymatic Glucose Sensor

We report the fabrication and testing of ultrafast response nonenzymatic glucose sensor based on the use of interlaced chain structure Au@CuS nanomaterial. The new Au@CuS nanomaterial was synthesized by a facile solvothermal method from L-cysteine、Cu(NO3)2·3H2O and Au Seeds without using additional surfactants or templates. The combination of Au and CuS solves the problems of poor electrical conductivity of CuS and the susceptibility of Au to toxicity, while the interlaced chain structure exposes more active sites to facilitate the diffusion of glucose molecules with a low resistance to increase the inter-electron transfer rate. The non-enzymatic Au@CuS-based glucose sensor showed a wide linear range with excellent sensitivity (5817.37 and 3629.78 μA mM−1cm−2), ultrafast response time (<0.1 s), excellent selectivity and outstanding long-term stability. Further, the designed glucose sensor was used to determine glucose in human blood serum sample with satisfactory result.

Development of hyaluronic acid-based electroconductive hydrogel as a sensitive non-enzymatic glucose sensor

Herein, a novel hyaluronic acid (HA)-based electroconductive hydrogel with enhanced mechanical properties was developed for the non-enzymatic glucose detection. As the main component of the polymeric network, HA was modified through methacrylation to integrate photocrosslinkable groups into its backbone. Electrical conductivity was provided to hydrogel by using two different conductivity sources as the introduction of reduced graphene oxide (rGO) and polyaniline (PANI) to HA-based hydrogel structure. The combination of these conductivity sources not only provided the sufficient electrical conductivity (1.58 ×10−5 S/cm) to hydrogels, but also ensured superior mechanical performance in terms of compressive strength (992.1 kPa) and elastic modulus (23.4 kPa) due to the synergistic effect of the rGO and PANI, that are the significant parameters for sensor applications. The electrochemical activity and sensor performance of the HA-based hydrogel were investigated via cyclic voltammetry (CV) and choronoamperometry (CA) methods. The fabricated HA-based hydrogel sensor exhibited high sensitivity as 421.42 µAmM−1cm−2 and selectivity for glucose with a low detection limit (0.3 µM). Moreover, it showed excellent long-term stability, reproducibility and anti-interference feature towards uric acid, ascorbic acid and sorbitol. Based on these results it could be stated that the developed HA-based hydrogel sensor containing ternary HA-rGO-PANI formulation for the first time in the literature might be served as a promising potential for the non-enzymatic glucose detection and it also offers a new perspective for fabricating efficient hydrogel-based biosensing systems for future studies.

Copper(II)-Incorporated Porphyrin-Based Porous Organic Polymer for a Nonenzymatic Electrochemical Glucose Sensor.

To date, the fabrication of multifunctional nanoplatforms based on a porous organic polymer for electrochemical sensing of biorelevant molecules has received considerable attention in the search for a more active, robust, and sensitive electrocatalyst. Here, in this report, we have developed a new porous organic polymer based on porphyrin (TEG-POR) from a polycondensation reaction between a triethylene glycol-linked dialdehyde and pyrrole. The Cu(II) complex of the polymer Cu-TEG-POR shows high sensitivity and a low detection limit for glucose electro-oxidation in an alkaline medium. The characterization of the as-synthesized polymer was done by thermogravimetric analysis (TGA), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy, and 13C CP-MAS solid-state NMR. The N2 adsorption/desorption isotherm was carried out at 77 K to analyze the porous property. TEG-POR and Cu-TEG-POR both show excellent thermal stability. The Cu-TEG-POR-modified GC electrode shows a low detection limit (LOD) value of 0.9 μM and a wide linear range (0.001-1.3 mM) with a sensitivity of 415.8 μA mM-1 cm-2 toward electrochemical glucose sensing. The interference of the modified electrode from ascorbic acid, dopamine, NaCl, uric acid, fructose, sucrose, and cysteine was insignificant. Cu-TEG-POR exhibits acceptable recovery for blood glucose detection (97.25-104%), suggesting its scope in the future for selective and sensitive nonenzymatic glucose detection in human blood.

A sensitive non-enzymatic electrochemical glucose sensor based on a ZnO/Co3O4/reduced graphene oxide nanocomposite

A novel sensitive and selective ZnO/Co3O4/rGO nanocomposite was fabricated using a hydrothermal method and used as a non-enzymatic electrochemical sensor for the detection of glucose.

A disposable and sensitive non-enzymatic glucose sensor based on a 3D-Mn-doped NiO nanoflower-modified flexible electrode.

Herein, nanoflower-shaped Mn-doped NiO nano-enzyme composites with high catalytic performance and excellent conductivity were grown on 3D flexible carbon fiber cloth (CFC) via hydrothermal and calcination methods to construct an efficient flexible glucose-sensitive detection electrode. For electrochemical-based sensors, high conductivity is a prerequisite for reliable data acquisition. To avoid the problems associated with using insulating Nafion or paraffin binders, we adopted a strategy of directly growing Mn-doped NiO onto the electrode surface, thereby avoiding interference due to the oxidization of species present in real samples at higher redox potentials, since Ni2+/Ni3+ has low redox potential. Therefore, the electrode has a linear range of 3-5166 μM for glucose detection, with a detection limit as low as 0.28 μM, showing excellent selectivity and reproducibility. The composite-modified electrode provides accurate detection results with real human serum samples, which are in full agreement with those of commercial blood glucose meters. In addition, we tested the glucose content in tea and sorghum fermentation broth at different stages, further expanding the application range of the Mn-NiO sensors. The nano-enzyme sensor fabricated herein offers a new idea for further integration into wearable flexible electronic devices for accurate glucose detection.

Corrosion-assisted in situ growth of NiCoFe-layered double hydroxides on Fe foam for sensitive non-enzymatic glucose detection.

Because of their remarkable qualities including changeable chemical composition, good redox characteristics, and ease of manufacture, non-enzymatic glucose sensors based on metallic hydroxides have attracted much interest. However, enhancement of their peroxidase-like catalytic activity is challenging due to their poor substrate affinity and low electrical conductivity, affecting electron transfer. Herein, a three-dimensional hierarchical architecture of Ni/Co-decorated-Fe layered double hydroxide (NiCoFe-LDH) was straightforwardly constructed on Fe foam (FF) via a feasible corrosion strategy, and the non-enzymatic glucose sensing properties of the NiCoFe-LDH/FF electrode were investigated. In the linear detection range of 0.010-0.1 mM, the electrode exhibits an extreme sensitivity of 5717 μA mM-1 cm-2 with a low threshold for glucose determination of 2.61 μM (S/N = 3) and a short reaction time (∼2 s), which is ascribed to its specific intertwined nanosheet-like morphology with rich electron transfer passages that enhance conductivity and improve the accessibility to more active catalytic sites for glucose oxidation. Moreover, the electrode shows excellent selectivity, good stability, and promising practicality for glucose detection in actual serum samples. These results indicate that the feasible corrosion approach towards the simple synthesis of trimetallic layered double hydroxide electrodes results in improved affinity and stability, holding new prospects for achieving reliable, cost-efficient, and eco-friendly non-enzymatic glucose detection.