Non-enzymatic Glucose Detection Research Articles

Facile synthesis of Cu/Co-ZIF nanoarrays for non-enzymatic glucose detection

Cu/Co-ZIF nanoflake arrays on carbon cloth are fabricated by controlling the introducing of Cu2+ ions during the growth of Co-ZIF. The Cu/Co-ZIF-20 electrode prepared with 20 mM Cu2+ possesses large electrochemically active surface area and bimetallic active sites, which can be revealed by cyclic voltammetry tests. The amperometric i–t measurements demonstrate that the Cu/Co-ZIF-20 electrode displays a wide linear range from 0.05 mM to 6.0 mM, and a high sensitivity of 1.03 mA mM−1 cm−2. Good selectivity, repeatability and practical applicability indicate its promising application in enzyme-free glucose sensing.

The dependence of Cu2O morphology on different surfactants and its application for non-enzymatic glucose detection

Herein, the Cu2O yolk-shell nanospheres, nanocubes and microcubes were successfully prepared by a simple seed-medium process. The formation of the Cu2O yolk-shell nanospheres can be attributed to the self-assembly process caused by the introduction of the seed medium. The formation mechanism of our obtained Cu2O yolk-shell nanospheres and the dependence of Cu2O morphology on different surfactants have been studied. The obtained samples were applied in the field of non-enzymatic glucose detection. The electrochemical response characteristics of the modified electrodes toward glucose were investigated by cyclic voltammetry (CV) and chronoamperometry (CA). The electrode modified with C-Cu2O (obtained by using CTAB as surfactant) shared the highest sensitivity of 3123 μAmM−1 cm-2, whereas, the electrode modified with S-Cu2O (obtained by using SDBS as surfactant) exhibited the lowest LOD of 0.87 μM and the widest linear range of 0.05–10.65 mM. All obtained sensors showed fast response to the addition of glucose. The obtained electrodes showed better responses to glucose than other coexisting interferences, indicating that the obtained electrodes had the acceptable selectivity to glucose. In addition, the stability for 5 consecutive weeks had also been studied and exhibited satisfactory results. The obtained electrode was also used to detect the glucose content in real serum. The acceptable selectivity, stability together with the excellent sensing ability in real serum make the obtained electrodes a potential for practical applications.

RGO@Cu2O@Cu Ternary Nanocomposite for High-Performance Non-Enzymatic Glucose Detection

Fast, reliable, and low-cost glucose detection methods are of great importance for the control of diabetes. In this study, Cu2O combined with Cu nanoparticles anchored on reduced graphene oxide (RGO), was synthesized to function as the electrode in a non-enzymatic glucose sensor. The synergistic effect between Cu nanoparticles and Cu2O, together with the high conductivity of RGO enabled considerably lower resistivity with greater glucose oxidation activity than pure Cu2O. The RGO@Cu2O@Cu electrode exhibited a high sensitivity of 1.112 mA mM−1 cm−2 with a detection limit of 0.019 μM, and the linear range is up to 4 mM. Additionally, the RGO@Cu2O@Cu electrode displayed good anti-interference performance within human blood and high stability while operating for a long duration. Significantly, the glucose detection capability of the as-designed electrode was comparable to commercial sensors, representing a valuable design for future non-enzymatic glucose sensing.

Non-enzymatic andrapid detection of glucose on PVA-CuO thin film using ARDUINO UNO based capacitance measurement unit.

Glucose measurement is one of the essential health monitoring practices for maintaining blood sugar levels. Here, we have fabricated a highly specific capacitive nano-sensor for non-enzymatic glucose detection. Capacitance measurements were carried out on polyvinyl alcohol capped copper oxide (PVA-CuO) thin films on indium tin oxide (ITO) coated glass using ARDUINO UNO. The capacitance study shows a decrease in capacitance with an increase in glucose concentrations. The applicability in real samples was performed by studying the glucose in the presence of fetal bovine serum. Most commonly found interfering agents were used for interference studies, which confirmed the capacitive nano-sensor specificity. The system was further checked for repeatability up to six readings and reproducibility up to 5 chips. The shelf-life study showed stability forfour weeks of a chip. These studies indicate that this capacitance-based measurement unit can be used for reliable, rapid, and non-enzymatic detection of glucose in real sample.

Laser-Assisted Surface Modification of Ni Microstructures with Au and Pt toward Cell Biocompatibility and High Enzyme-Free Glucose Sensing.

We investigated the influence of morphology of Ni microstructures modified with Au and Pt on their cell biocompatibility and electrocatalytic activity toward non-enzymatic glucose detection. Synthesis and modification were carried out using a simple and inexpensive approach based on the method of laser-induced deposition of metal microstructures from a solution on the surface of various dielectrics. Morphological analysis of the fabricated materials demonstrated that the surface of the Ni electrode has a hierarchical structure with large-scale 10 μm pores and small-scale 10 nm irregularities. In turn, the Ni-Pt surface has large-scale cavities, small-scale pores (1–1.5 μm), and a few tens of nanometer particles opposite to Ni-Au that reveals no obvious hierarchical structure. These observations were supported by impedance spectroscopy confirming the hierarchy of the surface topography of Ni and Ni-Pt structures. We tested the biocompatibility of the fabricated Ni-based electrodes with the HeLa cells. It was shown that the Ni-Au electrode has a much better cell adhesion than Ni-Pt with a more complex morphology. On the contrary, porous Ni and Ni-Pt electrodes with a more developed surface area than that of Ni-Au have better catalytic performance toward enzymeless glucose sensing, revealing greater sensitivity, selectivity, and stability. In this regard, modification of Ni with Pt led to the most prominent results providing rather good glucose detection limits (0.14 and 0.19 μA) and linear ranges (10–300 and 300–1500 μA) as well as the highest sensitivities of 18,570 and 2929 μA mM–1 cm–2. We also proposed some ideas to clarify the observed behavior and explain the influence of morphology of the fabricated electrodes on their electrocatalytic activity and biocompatibility.

Simultaneous Detection of Glucose and Fructose in Synthetic Musts by Multivariate Analysis of Silica-Based Amperometric Sensor Signals.

Silica-based electrodes which permanently include a graphite/Au nanoparticles composite were tested for non-enzymatic detection of glucose and fructose. The composite material showed an effective electrocatalytic activity, to achieve the oxidation of the two analytes at quite low potential values and with good linearity. Reduced surface passivation was observed even in presence of organic species normally constituting real samples. Electrochemical responses were systematically recorded in cyclic voltammetry and differential pulse voltammetry by analysing 99 solutions containing glucose and fructose at different concentration values. The analysed samples consisted both in glucose and fructose aqueous solutions at pH 12 and in solutions of synthetic musts of red grapes, to test the feasibility of the approach in a real frame. Multivariate exploratory analyses of the electrochemical signals were performed using the Principal Component Analysis (PCA). This gave evidence of the effectiveness of the chemometric approach to study the electrochemical sensor responses. Thanks to PCA, it was possible to highlight the different contributions of glucose and fructose to the voltammetric signal, allowing their selective determination.

Dendritic core-shell copper-nickel alloy@metal oxide for efficient non-enzymatic glucose detection

The synergy effect of bimetallic oxide shell and high electrically conductive metallic core enables the dendritic Cu-Ni/ nickel foam (NF) for detecting non-enzymatic glucose. • Binder-free Cu-Ni alloys@metal oxide was prepared by facile electrodeposition method. • The dendritic structure promotes glucose diffusion and provides rich active sites. • The bimetallic oxide shell and metallic core enable highly effective glucose sensing. A success has been achieved in the synthesis of dendritic core-shell copper-nickel alloy@metal oxide on nickel foam (Cu-Ni/NF) electrode for non-enzymatic glucose detection by going through a facile electrodeposition process followed by oxidation in NaOH solution. The direct electrodeposition approach facilitates the transfer of electrons in the binder-free electrode, and the dendritic structure promotes glucose diffusion while providing sufficient active sites required for the process of glucose electrocatlysis. Moreover, the unique core-shell structure promotes the catalytic activity towards glucose oxidation due to the synergistic effect caused by the bimetallic oxide shell and the metallic core that is conductive to electron transport. Accordingly, the Cu-Ni/NF electrode exhibits a high sensitivity of 11.34 mA mM −1 cm -2 , a low detection limit of 2 μM (S/N = 3), and a wide linear range of 1–600 μM for glucose detection. In addition, the electrode demonstrates such advantages as high selectivity, fast response time, and long duration stability. The designed Cu-Ni/NF electrode shows its massive potential of application for non-enzymatic glucose detection.

Mn2O3 porous microsheets prepared by a chemical precipitation method as an effective electrochemical sensor for non-enzymatic glucose detection

Mn2O3 porous microsheets prepared by a chemical precipitation method as an effective electrochemical sensor for non-enzymatic glucose detection

Enhancing the non-enzymatic glucose detection performance of Ni(OH)2 nanosheets via defect engineering

Electrochemical non-enzymatic glucose detection technology has been widely used in glucose sensors because of its simple operation and outstanding detection efficiency. Electrocatalysts that are earth-abundant and highly active are still to be explored to meet practical detection requirements. In this work, we report a strongly enhanced glucose detection performance of Ni(OH)2 by defect engineering. Ni(OH)2 nanosheets are synthesized by the electrochemical deposition method. Defects with various concentrations are introduced into Ni(OH)2 nanosheets by Ar plasma treatment. The defective Ni(OH)2 exhibits strongly enhanced glucose detection performance with higher sensitivity and wider linear response range. In-situ Raman spectra results suggest that defects can promote the deprotonation reaction of defective Ni(OH)2 to form NiOOH intermediates. In consequence, the oxidization of the glucose by the formed NiOOH is strongly facilitated, leading to the enhanced detection performance. The results in this work clarify the essential role of defects in determining the glucose detection performance of transition metal hydroxides and demonstrate defect engineering can be used for improving the performance of electrochemical non-enzymic sensors.

A new approach to in-situ uniform growth of Fe3O4 nanoparticles over thermally exfoliated rGO sheet for the non-enzymatic and enzymatic detection of glucose

• One step, in-situ pyrolysis method has been approached for synthesizing uniformly decorated Fe 3 O 4 over wrinkled rGO sheet (Fe 3 O 4 /erGO). • Significant enhancement in current response and prominent redox behaviour is observed for uniformly distributed Fe 3 O 4 /erGO composite over conventional way synthesized Fe 3 O 4 /rGO. • The non-enzymatic and enzymatic glucose sensor shows wide range linearity within 0–12mM and 1–19mM, respectively. • A low detection limit of 4.1µM and 2.2µM was observed for non-enzymatic and enzymatic Fe 3 O 4 /erGO, respectively. A new strategy has been adopted to synthesis agglomeration free uniformly decorated Fe 3 O 4 nanoparticles (NPs) over reduced graphene oxide (rGO) sheets using a solid-state pyrolysis method (Fe 3 O 4 /erGO). This strategy does not require any additional capping agents. The morphology and performance of the synthesised Fe 3 O 4 /erGO were then compared with a reference catalyst prepared by the conventional chemical precipitation method (Fe 3 O 4 /rGO). It was observed that the as-prepared Fe 3 O 4 /erGO shows the presence of higher defect densities, more wrinkled nature and significantly higher reactivity towards glucose oxidation than Fe 3 O 4 /rGO. The catalyst Fe 3 O 4 /erGO modified non-enzymatic and enzymatic sensor shows about 25 and 64 times increment in current response than Fe 3 O 4 /rGO towards glucose oxidation, attributed to the higher effective electrochemical surface area (ECSA). The sensitivity of both the non-enzymatic and enzymatic sensor is calculated, taking into account both the ECSA and the geometrical surface area (GA). Both the non-enzymatic and enzymatic sensor exhibit high sensitivity, wide range linearity with a low detection limit of 4.1 µM and 2.2 µM respectively. They also show good stability over 20 cycles. It was also observed that the performance of the non-enzymatic sensor in real blood is comparable with the clinically obtained value of glucose. Additionally, the non-enzymatic sensor also shows potential for simultaneous detection of glucose and uric acid. Thus, the features of both the non-enzymatic and enzymatic Fe 3 O 4 /erGO catalyst demonstrate its potential for use as a practical electrochemical sensor.

Development of Ag–Ni NPs loaded on MWCNTs for highly sensitive, selective and reproducible non-enzymatic electrochemical detection of glucose

Development of Ag–Ni NPs loaded on MWCNTs for highly sensitive, selective and reproducible non-enzymatic electrochemical detection of glucose

Copper and Nickel Microsensors Produced by Selective Laser Reductive Sintering for Non-Enzymatic Glucose Detection.

In this work, the method of selective laser reductive sintering was used to fabricate the sensor-active copper and nickel microstructures on the surface of glass-ceramics suitable for non-enzymatic detection of glucose. The calculated sensitivities for these microsensors are 1110 and 2080 μA mM−1·cm−2 for copper and nickel, respectively. Linear regime of enzymeless glucose sensing is provided between 0.003 and 3 mM for copper and between 0.01 and 3 mM for nickel. Limits of glucose detection for these manufactured micropatterns are equal to 0.91 and 2.1 µM for copper and nickel, respectively. In addition, the fabricated materials demonstrate rather good selectivity, long-term stability and reproducibility.

Development of non-enzymatic glucose electrode based on Au nanoparticles decorated single-walled carbon nanohorns

Gold nanoparticles (AuNPs)-based composite decorating with single-walled carbon nanohorns (SWCNHs) was synthesized and modified on a gold electrode for non-enzymatic glucose detection. The composite was synthesized by a simple covalent bonding method. The AuNPs with an average particle size of 40 nm are dispersed homogeneously on the surface of the SWCNHs. Therefore, the synergistic effect of the AuNPs and the SWCNHs leads to an excellent glucose sensing performance. The AuNPs/SWCNHs nanocomposites acted as a fast redox probe for non-enzymatic glucose oxidation exhibiting good performance, including a high sensitivity (275.33 and 352.5 μA cm−2 mM−1), a low detection limit of 0.72 μM (S/N = 3). AuNPs/SWCNHs glucose sensor also demonstrates good stability, reproducibility, and selectivity. Moreover, the glucose contents detected by this electrode was in right agreement with real value in blood samples. In summary, this study showed that AuNPs/SWCNHs nanoparticles have the potential to be used in non-enzymatic glucose detection.

Graphene oxide template based synthesis of NiCo2O4 nanosheets for high performance non-enzymatic glucose sensor

While glucose detection is ruled by enzyme-based glucose test strips, the chemically and thermally sensitive enzymes motivate the researchers to inspect chemically and thermally stable metal oxides as alternate sensing constituents for non-enzymatic glucose detection. Here, we report a synthesis of spinel nickel cobalt oxide (NiCo2O4) nanosheets-based catalyst for enzyme-free glucose sensing application via sonochemical approach using graphene oxide (GO) as nanosheets template and zeolitic imidazolate frameworks (ZIF-67) type nickel-cobalt metal-organic frameworks as oxide precursors (the catalyst named as gt-NiCo2O4 NSs). The physical characterization techniques confirmed that the as-synthesized gt-NiCo2O4 exhibited uniform porous and nanosheets morphology which can be obtained due to the ZIF-67 and GO template, respectively. Cyclic voltammetry and amperometric techniques employed for glucose oxidation at + 0.55 V using gt-NiCo2O4 NSs electrode in 0.1 M KOH. This sensor exhibited an excellent linear range (150 nM–8.86 mM), sensitivity (729.72 µA mM−1 cm−2) and lower detection level (7.35 nM; S/N ratio = 3) to glucose. Interestingly, the gt-NiCo2O4 NSs electrode displayed good recoveries to glucose in human blood serum and urine samples. Hence, the results indicates that gt-NiCo2O4 NSs is a promising electrode matrix with high sensitivity, excellent stability and good reproducibility that can enable the progress of enzyme-free glucose sensors.

Non-Enzymatic Glucose Detection Based on NiS Nanoclusters@NiS Nanosphere in Human Serum and Urine.

Herein, we report a non-enzymatic electrochemical glucose sensing platform based on NiS nanoclusters dispersed on NiS nanosphere (NC-NiS@NS-NiS) in human serum and urine samples. The NC-NiS@NS-NiS are directly grown on nickel foam (NF) (NC-NiS@NS-NiS|NF) substrate by a facile, and one-step electrodeposition strategy under acidic solution. The as-developed nanostructured NC-NiS@NS-NiS|NF electrode materials successfully employ as the enzyme-mimic electrocatalysts toward the improved electrocatalytic glucose oxidation and sensitive glucose sensing. The NC-NiS@NS-NiS|NF electrode presents an outstanding electrocatalytic activity and sensing capability towards the glucose owing to the attribution of great double layer capacitance, excessive electrochemical active surface area (ECASA), and high electrochemical active sites. The present sensor delivers a limit of detection (LOD) of ~0.0083 µM with a high sensitivity of 54.6 µA mM−1 cm−2 and a wide linear concentration range (20.0 µM–5.0 mM). The NC-NiS@NS-NiS|NF-based sensor demonstrates the good selectivity against the potential interferences and shows high practicability by glucose sensing in human urine and serum samples.

Facile synthesis of aminophenylboronic decorated electrospun CoFe2O4 spinel nanofibers with enhanced electrocatalytic performance for glucose electrochemical sensor application

CoFe2O4 nanoparticles uniformly decorated on the carbon nanofibers have been fabricated via electrospinning and subsequent calcination process. Aminophenylboric acid (APBA), as a glucose specific molecule, was modified on the surface of CoFe2O4@N-CNFs via the vapor chemical crosslinking approach. The fabricated APBA@CoFe2O4@N-CNFs hybrids were explored as electrocatalyst for the non-enzymatic electrochemical determination of glucose. Because of the synergistic effect of various materials, APBA@CoFe2O4@N-CNFs exhibits excellent non-enzymatic glucose detection properties involving sensitivity, selectivity, response time and linear correction. The remarkable electrocatalytic capability was mainly ascribed to the fact that N-CNFs with excellent electrical conductivity acted as a matrix guided the growth of CoFe2O4 nanoparticles, thus improving the dispersibility of CoFe2O4 and providing an enhanced efficient electron transport pathway. The spinel-type CoFe2O4 nanoparticles provided enhanced conductivity, while the porous structure of N-CNFs supplied the abundant active sites, which further improved the electrocatalysis. Besides, aminophenylboric acid, as a recognition molecule, was beneficial to the specific recognition of glucose molecules. Therefore, APBA@CoFe2O4@N-CNFs is promising as an important candidate material for glucose sensors due to its excellent performance, high efficiency and simple manufacturing process.

Glucose determination behaviour of gold microspheres-electrodeposited carbon cloth flexible electrodes in neutral media

Despite numerous advances in the field of nonenzymatic glucose detection, monitoring glucose in physiological applications is still a challenge and is mostly limited to electrode surface modification. This study proposes a simple method for electrodepositing cotton-like gold microspheres (CGMs) on a carbon cloth (CC) flexible electrode, with the potential for the functional supporting substrate to monitor glucose in a neutral environment. It was demonstrated that the voltammetric response of glucose oxidation increased with increases in glucose concentration in the 3D functional flexible substrate; moreover, the amperometric response of glucose oxidation increased over time. The results indicate that the functional flexible electrode—made of gold microspheres-based carbon cloth with a predefined geometry and pore-architecture network to promote the medium-permeation and synergetic effects between CGMs and CC—can be a suitable platform for measuring glucose variation in environments with neutral pH. This is particularly relevant because the oxygen-containing functional groups on the CC surface increase the dehydrogenation rate of glucose oxidation in neutral phosphate-buffered saline.

Nanocoral Ag for nonenzymatic glucose detection at extremely low operational potential

Silver (Ag) metal has excellent antibacterial properties, which makes it an ideal candidate for nonenzymatic glucose sensing devices. However, Ag nonenzymatic glucose sensors function at significantly high operating potential and suffer from poor selectivity. Here, we report that nanocoral reduced Ag (R-Ag) based nonenzymatic glucose sensors can be operated at potential as low as 0.1 V vs. Ag/AgCl and exhibits more than one order magnitude higher sensitivity in comparison to the Ag film. The R-Ag sensors can detect glucose in a wide range of concentrations varying from 100 u M to 2.5 mM linearly. The R-Ag sensors are also very robust, as performance remains unchanged even if sensors are stored under ambient conditions for 45 days.

Disposable and portable gold nanoparticles modified - laser-scribed graphene sensing strips for electrochemical, non-enzymatic detection of glucose

Glucose is one of the most important metabolites and a primary nutrient in human body metabolism. Abnormal levels of glucose can cause diabetes mellitus and related complications. Here, we developed a disposable and portable non-enzymatic glucose sensor strip based on gold-nanoparticles (AuNPs)-modified laser-scribed graphene electrode (LSGE). Disposable LSGEs, with a highly porous structure, were fabricated by laser scribing on a commercially available polyimide plastic sheets, followed by electrodepositing of AuNPs, that are electrocatalytic for glucose oxidation. The laser scribing process was optimised in term of laser power, laser speed and pulse per inch (PPI). The effect of number of the electrochemical deposition cycles of AuNPs on LSGE was also investigated and optimised. The sensor provides a linear detection range for the glucose concentrations between 10 µM to 10 mM with a limit of detection of 6.3 µM and shows a good selectivity towards interfering agents, such as urea L-ascorbic acid, uric acid, dopamine, and Na+. The LSGE/AuNP strips have a potential to be used as disposable glucose sensor strips for point-of-care glucose measurements, including self-monitoring and nutrition management.

Non-enzymatic sensing of glucose with high specificity and sensitivity based on high surface area mesoporous BiZnSbV-G-SiO2

It is profoundly appealing to build a common enzyme-free sensor for detection of glucose. We effectively synthesized a uniform and mesoporous BiZnSbV-G-SiO2 (BZSVGS) quaternary nanocomposite by electrodeposition on a Ni foam substrate. This BiZnSbV-G-SiO2@NF composite terminal has been used as an electrocatalyst for coordinated oxidation of glucose, in this manner acting as a high-performance non-enzymatic glucose sensor. Coordinated electrochemical estimation with the as-arranged anodes in PBS and urea showed that the BiZnSbV-G-SiO2 nanocomposite has a great electrocatalytic movement toward glucose oxidation in a neutral medium and a wide straight reaction from 0.06 to 0.1 μmol/L, a low detection constraint of 0.06 μmol/L (S/N = 3) at a low connected potential of + 0.20 V vs Ag/AgCl. This ponder moreover highlights the effect of diminishing anion electronegativity on upgrading the electrocatalytic proficiency by bringing down the potential required for glucose oxidation and long-term steadiness together with a brief reaction time of roughly 4 s highlights the promising execution of the BiZnSbV-G-SiO2@NF anode for non-enzymatic glucose detection with high accuracy and unwavering quality. Besides, it can be used for glucose location in human blood serum, promising its application toward assurance of glucose in genuine tests.