Development Of Non-enzymatic Glucose Sensor Research Articles

Revolutionizing Glucose Monitoring: Enzyme-Free 2D-MoS2 Nanostructures for Ultra-Sensitive Glucose Sensors with Real-Time Health-Monitoring Capabilities.

The growing requirement for real-time monitoring of health factors such as heart rate, temperature, and blood glucose levels has resulted in an increase in demand for electrochemical sensors. This study focuses on enzyme-free glucose sensors based on 2D-MoS2 nanostructures explored by simple hydrothermal route. The 2D-MoS2 nanostructures were characterized by powder X-ray diffraction, energy-dispersive X-ray spectroscopy, scanning electron microscopy, transmission electron microscopy, Raman spectroscopy, and XPS techniques and were immobilized at GCE to obtain MoS2-GCE interface. The fabricated interface was characterized by electrochemical impedance spectroscopy which shows less charge transfer resistance and demonstrated superior electrocatalytic properties of the modified surface. The sensing interface was applied for the detection of glucose using amperometry. The MoS2-GCE-sensing interface responded effectively as a nonenzymatic glucose sensor (NEGS) over a linearity range of 0.01-0.20 μM with a very low detection limit of 22.08 ng mL-1. This study demonstrates an easy method for developing a MoS2-GCE interface, providing a potential option for the construction of flexible and disposable nonenzymatic glucose sensors (NEGS). Moreover, the fabricated MoS2-GCE electrode precisely detected glucose molecules in real blood serum and urine samples of diabetic and nondiabetic persons. These findings suggest that 2D-MoS2 nanostructured materials show considerable promise as a possible option for hyperglycemia detection and therapy. Furthermore, the development of NEGS might create new prospects in the glucometer industry.

Synergistic Effect of Composite Nickel Phosphide Nanoparticles and Carbon Fiber on the Enhancement of Salivary Enzyme-Free Glucose Sensing.

An electrospinning method was used for the preparation of an in situ composite based on Ni2P nanoparticles and carbon fiber (FC). The material was tested for the first time against direct glucose oxidation reaction. The Ni2P nanoparticles were distributed homogeneously throughout the carbon fibers with a composition determined by thermogravimetric analysis (TGA) of 40 wt% Ni2P and 60 wt% carbon fiber without impurities in the sample. The electrochemical measurement results indicate that the GCE/FC/Ni2P in situ sensor exhibits excellent catalytic activity compared to the GCE/Ni2P and GCE/FC/Ni2P ex situ electrodes. The GCE/FC/Ni2P in situ sensor presents a sensitivity of 1050 µAmM-1cm-2 in the range of 5-208 µM and a detection limit of 0.25 µM. The sensor was applied for glucose detection in artificial saliva, with a low interference observed from normally coexisting electroactive species. In conclusion, our sensor represents a novel and analytical competitive alternative for the development of non-enzymatic glucose sensors in the future.

Fabrication, characterization of NiO–Co3O4/rGO based nanohybrid and application in the development of non-enzymatic glucose sensor

The current study is reporting the synthesis and characterization of NiO–Co3O4/rGO nanohybrid for nanocomposite for nonenzymatic glucose sensing. The prepared nanohybrids sample was characterized by X-rays diffraction (XRD), fourier transforms infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). The XRD analysis exhibited the cubic crystalline phase for both NiO and Co3O4 in the binary composite. The vibrational mode of NiO and its nanohybrid with reduced graphene oxide (rGO) was defined using FTIR spectral analysis. SEM images of the nanoparticles depicted a non-spherical pattern randomly distributed throughout the whole matrix. The prepared sensor exhibited promising results for glucose sensitivity (345 μA mM) with a wide range of linear response from 1.23 × 10-4 mM to 10 mM and a low limit of detection of 0.13 μM. Further, the interference study was also performed using 100 µM fructose (FR), lactose (LA), uric acid (UA) and ascorbic acid (AA) and results exposed that these interfering species has not affected glucose determination. The obtained results suggested that the nanohybrid has enormous potential to act as a credible sensor for the determination of glucose.

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.

Effects of nickel–cobalt material properties on glucose catalysis

The development of non-enzymatic glucose sensors becomes even more significant as the number of diabetics worldwide continues to increase. Ni–Co alloy can be fabricated by electrodeposition and used as a catalyst for glucose so that it is a suitable electrode material for non-enzymatic electrochemical glucose sensors. The results of material analyses reveal that the catalytic performance for glucose is related to the crystallographic structure of Ni–Co alloy. A Ni–Co based non-enzymatic glucose sensor with a majority of hexagonal close packed (hcp) lattice exhibits better catalytic performance and, moreover, the catalysis of glucose is a quasi-reversible redox process, either in film-type or nanowire-type alloy. However, the nanowire-type Ni–Co glucose sensor has a wider sensing range than the film-type sensor. Ni–Co glucose sensor possesses excellent anti-interference without being influenced by the chemicals coexisting with glucose. These results demonstrate the effect of the crystal structure of Ni–Co on glucose catalysis and suggest the electroplating conditions for the preparation of Ni–Co non-enzymatic glucose sensor with good catalytic performance and excellent anti-interference ability.

Nonenzymatic Sweat-Based Glucose Sensing by Flower-like Au Nanostructures/Graphene Oxide

The development of a nonenzymatic glucose sensor working in real human body conditions through a noninvasive sampling approach has attracted considerable attention. Hence, this work focuses on the development of a new nonenzymatic glucose sensor based on flower-like Au nanostructures (F-AuNTs) and graphene oxide (GO) as a supporting matrix. The F-AuNTs–GO hybrid was synthesized by simple drop casting of the GO suspension onto the graphite sheet (GS) followed by electrodeposition of F-AuNTs on GO nanosheets at 3 V in a two-electrode system. The electrocatalytic activity of the F-AuNTs–GO/GS sensor toward glucose electrooxidation was initially evaluated in a 0.1 M buffer phosphate solution (pH 7.4). The fabricated electrode shows a linear range (5 nM to 5 μM), a fast response time (6 s), a low detection limit (385 nM), and high sensitivity (162,210 μA mM–1 cm–2). Furthermore, this sensor exhibits very good selectivity in the presence of interferences such as lactic acid, uric acid, NaCl, dopamine, ascorbic acid, and inorganic salts. After obtaining the desired results, a screen-printed electrode (SPE) modified by the F-AuNTs–GO hybrid was prepared for the determination of glucose concentration from artificial sweat to evaluate the noninvasive capability of the proposed sensor. The F-AuNTs–GO/SPE exhibits good behavior for glucose detection with a long linear range of 160 nM to 82 μM and 160 μM to 5 mM, a high sensitivity of 474,617 μA mM–1 cm–1, and a low detection limit of 123 μM. Therefore, the electrochemical experiments demonstrated that F-AuNTs–GO possessed the excellent ability for electrochemically catalysis of glucose oxidation in both buffer solution and artificial sweat. Finally, the capability of the fabricated electrode was successfully investigated for glucose measurement in sweat samples. The outstanding performance of the F-AuNTs–GO-based sensor can be attributed to the superior catalytic activity of the F-AuNTs well dispersing onto GO nanosheets, which provides an excellent sensing platform owing to the enhanced electrical conductivity and large surface area. This study demonstrates that the F-AuNTs–GO hybrid is a promising candidate for the detection of glucose in sensor applications.

Nonenzymatic glucose sensor design based on carbon fiber ultra-microelectrode: Controlled with a manual micro adjuster

Interest in designing and manufacturing glucose sensors based on metal oxide-modified microelectrodes is growing and leading to the increased research efforts to develop continuous glucose measurements. A non-enzymatic glucose sensor based on an ultra-microelectrode is presented. A carbon fiber microelectrode electrodeposited by nickel nanoparticles (NiCFME) and activated as a nonenzymatic glucose sensor. The modified carbon microfiber was attached to a micro adjuster to adjust the height of the electrode inside the solution, which improved the accuracy of the microelectrode performance. The microstructure and morphology of the electrodes and nanoparticles investigated using SEM, EDX and XRD. The electrocatalytic glucose oxidation behavior of the sensing NiCFME got analyzed by cyclic voltammetry and amperometric measurements in alkaline medium. Achieved results demonstrated that the fabricated sensor displays the sensitivity up to 8.5 μA μM−1 cm−2 with a low detection limit of 3.0 μM, LOQ of 10.0 μM, with a linearity range of 10.0 μM–150.0 μM and response time about 0.4 s for glucose detection. Designed sensor had an appropriate good stability and significant selectivity towards glucose. Finally, the proposed sensor was successfully applied in determination of glucose in human blood plasma samples. The results illustrated; the proposed design is a promising candidate for the development of nonenzymatic glucose sensors.

Synthesis of CoNi2S4 Nanoflake-modified Nickel Wire Electrode for Sensitive Non-enzymatic Detection of Glucose

In this study, CoNi2S4 nanoflake-modified nickel wire sensor for detecting glucose was successfully prepared by hydrothermal method and room temperature vulcanization. Due to the special morphology with large specific surface area and the synergistic effect between Ni and Co, the active material had good electrochemical performance as a biosensor. The results showed that the CoNi2S4 nanoflake-modified nickel wire electrode exhibited good performance in the measurement of glucose amperes. Two linear response ranges (0.001∼3 mM and 3∼8 mM) were exhibited when glucose was tested using the prepared electrode, and the corresponding sensitivity was 2473 μA mM−1 cm−2 and 1794 μA mM−1 cm−2, respectively. The detection limit was 0.3 μM with a signal-to-noise ratio of 3. These results indicate that the CoNi2S4 nanoflake-modified nickel wire electrode has broad application prospects in the development of non-enzymatic glucose sensors.

Nonenzymatic Glucose Sensors Based on Copper Sulfides: Effect of Binder-Particles Interactions in Drop-Casted Suspensions on Electrodes Electrochemical Performance

The constant progress in novel nanomaterials synthesis has contributed to the rapid development of nonenzymatic glucose sensors. For working electrodes preparation, drop casting proved to be the most convenient and thus most widely applied method. However, appropriate interpretation of obtained electrochemical signal requires in-depth knowledge of limitations related to this technique. In this study, we prepared solutions based on commonly reported polymers for nanostructures immobilization and investigated their influence on copper sulfides distribution on the electrode. Characterization of suspensions properties and behavior of particles during droplet drying revealed that nonionic polyvinylpyrrolidone (PVP) was favorable for electrodes modification with copper sulfides in comparison with Nafion and chitosan. It ensured homogeneity of the suspension as well as the uniform coverage of the electrode surface with particles, what resulted in increased active surface area and, therefore, higher signal from glucose addition. On the other hand, when cationic chitosan was used as a binder, suspensions were agglomerated and, within dry deposits, a coffee-ring effect was observed. Appropriate adjustment of material and polymer interactions led to enhanced electrode electrochemical performance.

A Review on the Development of Non-Enzymatic Glucose Sensor Based on Graphene-Based Nanocomposites

In this 21th century, the demand for glucose sensors in monitoring diabetes reaches a year-on-year peak due to the unhealthy lifestyle of society. Therefore, it is the utmost important task for scientists and researchers to develop a highly efficient and effective glucose sensor. However, conventional enzymatic glucose sensors have showed some drawbacks and the underlying issues faced by enzymatic glucose sensors are outlined in this paper. With the tremendous advancement of science and technology, the field of diabetes monitoring has evolved from enzymatic to nonenzymatic glucose sensor that heavily emphasized on the usage of nanomaterial. This transformation is supported by various justifications such as a better stability of nonenzymatic sensors towards the surrounding, higher sensitivity and ease of fabrication. Numerous materials including graphene, noble metals, (transition) metal oxides and composites have been explored for its potential in the development and performance improvement of nonenzymatic glucose sensors. This paper reviewed nonenzymatic glucose sensors, their mechanism of glucose oxidation and various promising graphene-based nanocomposite systems as well as the challenges and future perspectives of glucose biosensors.

Platinum and zinc oxide modified carbon nitride electrode as non-enzymatic highly selective and reusable electrochemical diabetic sensor in human blood

Development of non-enzymatic glucose sensor is essential to reduce the cost of diabetes regular monitoring. Here, graphitic carbon nitride (g-C3N4) is modified with platinum and zinc oxide for non-enzymatic electrochemical glucose sensing in physiological conditions for the first time in the literature. The interactions between Pt, g-C3N4 and the ZnO are studied using different physicochemical characterization techniques. The Electrochemical glucose sensing at the ZnO-Pt-gC3N4 occurs at low applied potential of +0.20 V (vs. Ag/AgCl) with high sensitivity 3.34 μA/mM/cm2 and fast response (5 s) time. This sensor exhibited a wide linear range 0.25–110 mM with lower limit of detection of 0.1 µM. The architectured sensor was evaluated in human blood, serum and urine samples. The sensor is 4 time reusable in whole blood without activity deterioration. This reusable surface helps to reduce the cost of strip.

Metal oxide-based composite for non-enzymatic glucose sensors

The increasing demand for monitoring the glucose concentration in the blood of diabetic patients has aroused the attention of researchers to prepare high-performance glucose biosensors. After decades of development, enzyme-based biosensors have gradually matured and commercialized, but they still suffer from insufficient stability due to the inherent defects of the enzyme. Non-enzymatic glucose sensor was proposed to address this issue. The introduction of nanotechnology has provided more possibilities for the preparation of highly efficient catalytic materials. Among the synthesized electrocatalysts, metal oxides are one of the most important components owing to their outstanding properties. Recent studies have integrated metal oxides with other materials to further improve sensor performance. This review focuses on the application of metal oxide-based hybrid structure in the glucose sensor, mainly including metal oxide/metal oxide, metal/metal oxide, and carbon material/metal oxide. The preparation method, electrochemical properties, and catalytic mechanism of the sensors are discussed in detail. Finally, we present some of the existing challenges and make personal predictions for the future development of non-enzymatic glucose sensors.

Ultrasensitive Non-Enzymatic Glucose Sensors Based on Hybrid Reduced Graphene Oxide and Carbonized Silk Fabric Electrodes Decorated with Cu Nanoflowers

The preparation of substrate with high specific surface area and conductivity is very important in the development of non-enzymatic glucose sensors. This study presents a non-enzymatic glucose sensor electrode based on a hybrid reduced graphene oxide (rGO) and carbonized silk fabric (CSF) substrate obtained by immersing silk fabric in a graphene oxide solution and carbonizing at 950 °C in an Ar atmosphere, and then decorating the rGO/CSF surface with Cu nanoflowers by electrodeposition. The optimum Cu-rGO/CSF sensor electrode exhibits high glucose sensitivities of 6613.3 μA mM−1 cm−2 and 1541.7 μA mM−1 cm−2 with linear responses over separate glucose concentration ranges of 0.05–4.0 mM and 4.0–7.0 mM due to the rGO/CSF substrate has high specific surface area, good conductivity and the Cu nanoflowers have high catalytic activity. The electrode also provides a lower limit of detection of 2.27 μM at a signal-to-noise ratio of 3 and high stability in the air. These results demonstrate that the proposed electrode material facilitates the development of simple and accurate non-enzymatic glucose sensors.

Fabrication of highly sensitive non-enzymatic sensor based on Pt/PVF modified Pt electrode for detection of glucose

A novel and simple non-enzymatic glucose sensor was successfully fabricated by immobilization of platinum (Pt) particles on polyvinylferrocene-coated Pt electrode (Pt/PVF/Pt). The use of Pt/PVF composite in the development of non-enzymatic glucose sensors has been reported for the first time in this paper. The Pt particles were electrochemically incorporated in the PVF matrix through the chemical reaction between potassium hexachloroplatinate (IV) K2PtCl6 solution and PVF. The as-prepared Pt/PVF/Pt electrode was evaluated towards oxidation of glucose in alkaline media (0.1 M NaOH). The characterization and evaluation of various analytical factors such as sensitivity, selectivity, stability, reproducibility, and detection limit were investigated by cyclic voltammetry (CV) and chronoamperometry (CA) techniques. The Pt/PVF/Pt sensor showed fast response time of less than 3 s with linear glucose concentration range from 0.1 to 11.0 mM (R2 = 0.996). The sensitivity of the sensor was 327 μA mM−1 cm−2 with low detection limit of 0.026 mM. The sensor showed good stability and reproducibility along with excellent anti-interference properties to ascorbic acid, uric acid, sucrose, and fructose. Finally, the applicability of the as-prepared Pt/PVF/Pt sensor was successfully studied for detection of glucose in variety of juice samples. The results obtained for our sensor confirm that it is a promising non-enzymatic glucose sensor to be used for practical purpose.

Fabrication of Ni/Cu ordered bowl-like array film for the highly sensitive nonenzymatic detection of glucose

Ni/Cu ordered bowl-like array film was successfully synthesised by a two-step electrodeposition method using monodisperse polystyrene spheres as a template. A Cu bowl-like array was first electrochemically deposited into the template. After dissolving the polystyrene spheres, a Ni film was electrodeposited onto the Cu array. Morphology analysis revealed that the final product had an ordered hexagonal close-packed bowl-like pore array composed of nanoparticles. The Ni/Cu bowl-like array film could be directly used as a glucose-sensing material. It exhibited a high sensitivity of 3924 μA mM−1 cm−2, a wide linearity ranging from 0.5 μM to 2.5 mM and detection limit as low as 0.05 μM. These results indicate that the Ni/Cu bowl-like array film is promising for the development of nonenzymatic glucose sensors.

Glucose sensor based on porous Ni by using a graphene bottom layer combined with a Ni middle layer

Porous nickel (pNi) was prepared by a hydrogen bubble template method by using a graphene bottom layer combined with a Ni middle layer on Cu foil substrate. The crystal structure and the pore size of the pNi were characterized by XRD and SEM, respectively. The TEM, SAED and XPS exhibited that the pNi and graphene as well as the Ni(OH)2 with high activity were formed on the surface. The glucose sensing performance in alkaline environments was estimated by cyclic voltammetry and chronoamperometry. The pNi as-prepared exhibits a high sensitivity of 6161μA/mM−1cm−2 within a linear range of 0.0005–1.0 mM, which is much better than that of pNi on Cu foil. The large quantities of active site supplied by the pNi with pore size as low as 1–15 μm as well as the high electron transfer ability between electrode and active reaction center induced by the graphene play important roles in obtaining the pNi as-prepared with high sensitivity and a broad linear range. It provides a new idea for the development of non-enzymatic glucose sensor especially based on porous Ni with graphene bottom layer and Ni middle layer.

Cu NPs@NiF electrode preparation by rapid one-step electrodeposition and its sensing performance for glucose

Copper nanoparticles (Cu NPs) were uniformly deposited on a nickel foam substrate (Cu NPs@NiF electrode) rapidly by one-step electrochemical deposition in the aqueous solution of copper sulfate, which can be successfully applied to catalyze glucose oxidation, and act as a non-enzymatic glucose sensor. The specific structure and morphology of Cu NPs were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The electro-oxidation of glucose on Cu NPs@NiF catalytic oxidation of process was proved by cyclic voltammetry (CV). It is found that Cu NPs show remarkable catalytic activity to glucose, involving in multistep catalytic of Cu NPs, in which the transform from Cu (II) into Cu (III) is the key to success. The performances of electrode sensitivity were investigated by CV and chronoamperometry methods in alkaline conditions. It is found that the developed sensor had excellent glucose sensing performances, including two-section broad linear detection ranges (0.002–0.650 mM and 0.65–6.00 mM), high corresponding sensitivity (2679 μA cm−2 mM−1 and 1122 μA cm−2 mM−1), fast response time (<3 s) and a low detection limit (0.5 μM, S/N = 3). In short, the Cu NPs@NiF electrode developed by low-cost, efficient and simple preparation method is expected to be used for the development of non-enzymatic glucose sensors.

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.

Nonenzymatic glucose sensor based on icosahedron AuPd@CuO core shell nanoparticles and MWCNT

In this paper, a novel type of icosahedron AuPd – copper oxide (CuO) core shell nanoparticles (AuPd@CuO NPs) – modified multi-walled carbon nanotubes (MWCNT) electrode for sensitive nonenzymatic glucose detection has been fabricated. AuPd@CuO core shell NPs were synthesized with icosahedron bimetallic AuPd nanocrystals as core and CuO nanoparticles (CuO NPs) as shell in a mild condition and a short time. MWCNT and AuPd@CuO NPs were characterized by field emission electron microscopy (FESEM), transmission electron microscope (TEM), energy dispersive X-ray detector (EDS) and Fourier transform infrared spectra (FT-IR). In this sensor, icosahedron AuPd@CuO NPs showed much higher electrocatalytic activity towards glucose oxidation. At an applied potential of +0.34V, this sensor showed a good sensitivity of 744.98μAmM−1cm−2 to glucose. In addition, a linear range of 3.00×10−5 to 9.31×10−3M (R2=0.997) was obtained with a detection limit of 0.10μM (S/N=3). More importantly, the AuPd@CuO NPs/MWCNT modified electrode is highly resistant against poisoning by chloride ion and inference and was used to analyze glucose concentration in human serum samples. The modified electrode exhibits an enhanced electrocatalytic property, low working potential, good sensitivity, low detection limit, excellent selectivity, and good stability towards glucose oxidation, thus the AuPd@CuO NPs/MWCNT modified electrode is promising for the future development of nonenzymatic glucose sensors.

A Facile Electrochemical Preparation of Violarite (Ni2FeS4) Nanosheets on Carbon Sheet and its Application towards Non-Enzymatic Glucose Sensing

A simple electrochemical method is reported for the preparation of Ni2FeS4 (NFS) nanosheets on carbon sheet (CS)substrate. FESEM and EDAX data confirmed the presence of nanosheet morphology with required stoichiometry. NFS modified CS is employed as an electrode material for the development of non-enzymatic glucose sensor. Impedance data showed low charge transfer resistance for NFS/CS compared to bare CS, indicated its high charge transfer capability. The developed sensor exhibited wide linear response in two different glucose concentration ranges of 10 to 1850 μM and 2350 to 7750 μM with the sensitivity value of 0.71 μA μM−1 cm−2 and 0.14 μA μM−1 cm−2. Moreover, the selectivity data demonstrated good anti-interference property of NFS/CS towards glucose in the presence of possible interfering species viz. ascorbic acid, dopamine and uric acid.