Selective Non-enzymatic Glucose Research Articles

Non-enzymatic glucose electrochemical sensor based on nitrogen-doped graphene modified with polyaniline and Fe3O4@MIL-101-NH2 nano framework

In this study, a novel highly sensitive and selective non-enzymatic glucose sensor was fabricated by coating simple and cheap graphite sheet (GS) electrodes with a proper conductive nanocomposite containing nitrogen-doped functionalized graphene (NFG), conductive polyaniline (PANI), and core–shell nanoparticles (Fe3O4@MIL-101-NH2). The results revealed that the core centers of iron oxide nanoparticles shelled by MIL-101-NH2 enhanced the electron transfer and led to more conductivity, also their existence caused the limitation of the MOF’s low conductivity. In addition, using Fe3O4@MIL-101-NH2 in the nanocomposite structure led to more sensitivity and selectivity at glucose monitoring due to its amine groups and unique structure. The results showed that NFG/PANI/Fe3O4@MIL-101-NH2 nanocomposite provided a large surface area besides enhanced electron transfer and catalytic properties that lead to proper oxidation of glucose with two linear ranges of 0.5 – 10 µM and 100 µM – 25 mM and a low detection limit of 0.3 µM (S/N = 3). Furthermore, the relative standard deviation (RSD%) in all detection processes was lower than 9 %. Finally, the performance of fabricated non-enzymatic sensor (GS/NFG/PANI/Fe3O4@MIL-101-NH2) in human fluids real samples including serum and plasma was acceptable which significantly indicates that it is toward monitoring of glucose in clinical applications.

Molybdenum-cobalt micro-nano interface assisted ultrasensitive and selective non-enzymatic glucose biosensor

In the present work, we report highly sensitive and selective non-enzymatic glucose biosensor using novel hybrid CoOOH nanospheres decorated MoO3 nanobelts (MoCo). MoCo nanocomposite exhibits superior sensing properties toward glucose detection due to its improved electron transfer capability along with the large surface area. The biosensor achieved an excellent linear range within the concentration of 0.001–1.0 mM correspond to the amperometric current response was obtained from GCE/MoCo/Nafion electrode. The biosensing electrode is resulted a linear regression coefficient (R2 = 0.9959) and limit of detection (LOD) is 56 µM at (S/N = 3). The performance optimization of the biosensor was performed at a different operating temperature subjected to successive glucose additions. A remarkable selectivity is obtained against to the glucose at presence of different interfering substance and long-term stability of 30 days reached without a noticeable decay in the amperometric current response.

Facile synthesize surfactants and binder-free nanoflake Co(OH)2 on CuCo2S4 nanowire for highly sensitive and selective non-enzymatic glucose sensor

The cross-linked Co(OH)2/CuCo2S4/Ni composite material has been successfully prepared by a simple method. CuCo2S4 nanoneedles are grown on NF by hydrothermal method, and then Co(OH)2 nanolayer was constructed by constant potential deposition. This nanostructure provides a good conductive network for effective charge transfer, which can detect direct and non-enzymatic reactions of glucose oxidation at low potential. In this paper, the microstructure and electrochemical properties of the prepared Co(OH)2/CuCo2S4 composites were characterized and tested. In the electrochemical sensing process, Co(OH)2/CuCo2S4 nanomaterials show high sensitivity, low detection limit, excellent selectivity, and linear response, reaching wide linear range of 1 μM-6.957 mM, high sensitivity of 2714.7 μA mM−1 cm−2 and a low detection limit of 0.26 μM. In addition, the sensor shows fast response time (within 2.5s), excellent selectivity and stability. CuCo2S4 nanowire array increases active surface area for the catalytic reaction and act as a stable conductive scaffold of Co(OH)2 to promote electron transfer. This low-cost and straightforward detection method offers a new strategy for non-enzymatic glucose detection.

Covalent Immobilisation of a Nanoporous Platinum Film onto a Gold Screen-Printed Electrode for Highly Stable and Selective Non-Enzymatic Glucose Sensing

Progress in the development of commercially available non-enzymatic glucose sensors continues to be problematic due to issues regarding selectivity, reproducibility and stability. Overcoming these issues is a research challenge of significant importance. This study reports a novel fabrication process using a double-layer self-assembly of (3 mercaptopropyl)trimethoxysilane (MPTS) on a gold substrate and co-deposition of a platinum–copper alloy. The subsequent electrochemical dealloying of the less noble copper resulted in a nanoporous platinum structure on the uppermost exposed thiol groups. Amperometric responses at 0.4 V vs. Ag/AgCl found the modification to be highly selective towards glucose in the presence of known interferants. The sensor propagated a rapid response time <5 s and exhibited a wide linear range from 1 mM to 18 mM. Additionally, extremely robust stability was attributed to enhanced attachment due to the strong chemisorption between the gold substrate and the exposed thiol of MPTS. Incorporation of metallic nanomaterials using the self-assembly approach was demonstrated to provide a more reproducible and controlled molecular architecture for sensor fabrication. The successful application of the sensor in real blood serum samples displayed a strong correlation with clinically obtained glucose levels.

Nanostructured copper selenide as an ultrasensitive and selective non-enzymatic glucose sensor

CuSe nanostructures exhibit high-efficiency for glucose detection with high sensitivity (19.419 mA mM−1 cm−2) and selectivity at low applied potential (0.15 V vs. Ag|AgCl), low detection limit (0.196 μM) and linear detection range (100 nM to 40 μM).

Non-enzymatic sensor based on nitrogen-doped graphene modified with Pd nano-particles and NiAl layered double hydroxide for glucose determination in blood

Herein, a novel highly sensitive and selective non-enzymatic glucose sensor was developed. This sensor was prepared with a one-step electrodeposition process, which means that the palladium nanoparticles and NiAl layered double hydroxide were electrosynthesized simultaneously (Pd-NiAl-LDH) on a graphite sheet electrode (GS) covered by nitrogen-doped functionalized graphene (NFG). The sensing performance was investigated by linear sweep voltammetry (LSV), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and chronoamperometry (CA) techniques. The results revealed that the one-step electrodeposition of Pd-NiAl-LDH nanocomposite on NFG provided a large surface area containing Ni and Pd electroactive centers and enhanced the electron transfer. This resulted in a remarkable effect on signal amplification toward glucose oxidation, with a wide linear range from 500 nM to 10 mM, an acceptable sensitivity of 315.46 μA. cm−2. dec−1 and a low detection limit of 234 nM based on a signal to noise ratio of 3. The relative standard deviation (RSD%) in all detection tests was lower than 5% and also the performance of fabricated GS/NFG/Pd-NiAl-LDH electrode which investigated in human real samples including serum, plasma and blood was acceptable, indicating the ability of the fabricated sensor in biological and clinical applications.

Binary MnO2/Co3O4 @ Well-aligned Electrospun Carbon Nanofibers for Sensitive, Nonenzymatic Glucose Sensing

A binary metal oxide composite, manganese oxide/cobalt oxide (MnO2 /Co3O4), on a well-aligned electrospun carbon nanofibers (MnO2/Co3O4@ECNFs) mat was synthesized via a simple one-step template-free electrodeposition process at a constant low-current (60 μA) for hours. The MnO2/Co3O4@ECNFs nanocomposite mat show excellent electrocatalytic activity towards sensitive and selective non-enzymatic glucose sensing. The MnO2/Co3O4@ECNFs nanocomposite were tested and characterized thoroughly by high resolution imaging and spectroscopic techniques. The results reveal that the binary metal oxides are uniformly deposited on the well-aligned ECNFs mat with high porosity, effective interconnectivity and large number of extended conducting channels. The electrochemical impedance spectroscopy (EIS) of the nanocomposite mat electrode show very good conductivity in 0.1 M KCl containing 5 mM [Fe(CN)6]3-/4-. The electrocatalytic activity of as-prepared MnO2/Co3O4@ECNFs for oxidation of glucose were performed by cyclic voltammetry (CV) and chronoamperometry (CA); and the experimental results demonstrate a superior sensing performance for glucose detection, including a rapid response (5 seconds), a wide dynamic range (up to 10.9 mM), excellent sensitivity of 973.91 μA mM-1 cm-2 and a detection limit of 0.02 μM (S/N=3) with satisfactory selectivity, reproducibility and stability. The plausible reactions involved for the electrocatalytic oxidation of glucose by the binary metal oxides are as follows.1 2Co02 + C6H1206 (glucose) -> 2Co00H + C6H1006 (gluconolactone) (1) 2Mn0 2 + C6H1206 (glucose) -> 2Mn00H + C6H1006 (gluconolactone) (2)Finally, the nanocomposite electrode was tested in glucose spiked human serum samples. The recovery rates of a series of standard glucose solutions are nearly 100%, suggesting the excellent performance and potential towards development of a nonenzymatic glucose biosensor for practical applications. Reference 1. Han, L.; Yang, D.-P.; Liu, A., Leaf-Templated Synthesis of 3d Hierarchical Porous Cobalt Oxide Nanostructure as Direct Electrochemical Biosensing Interface with Enhanced Electrocatalysis. Biosensors and Bioelectronics 2015, 63, 145-152.

Highly sensitive and selective non-enzymatic glucose detection based on indigo carmine/hemin/H2O2 chemiluminescence.

A new chemiluminescence (CL) system, indigo carmine/glucose/hemin/H2O2, has been found and developed for non-enzymatic detection of indigo carmine (IC) and glucose. The CL response increases linearly with IC concentrations from 3.2 μM to 10 mM and glucose concentrations from 0.06 μM to 3.5 mM. The detection limits are 1.45 μM and 15.0 nM for IC and glucose, respectively. This method allows the determination of glucose in blood and urine after simple dilution. The recoveries for the determination of glucose are between 98.5% and 101.0% in blood and between 98.5% and 101.3% in urine. This method shows good sensitivity, selectivity, simplicity, and is low cost, suggesting its promising broad applications.

Three-dimensional porous Ni, N-codoped C networks for highly sensitive and selective non-enzymatic glucose sensing

Carbon materials have received intensive attention due to their unique property in the field of electrochemical analysis. As transition metallic heteroatom and nitrogen-codoped carbon (M-N-C) materials commonly exhibit enhanced electrochemical activity for the tuned electronic structure, therefore, fabricating a novel structure of M-N-C material for electrochemical analysis is highly pursued. Herein, an in-situ self-growth NaCl-templated strategy is proposed to fabricate three-dimensional porous Ni, N-codoped carbon material (3D Ni-N-C). The as-obtained 3D Ni-N-C demonstrates superior electrochemical performance toward glucose oxidation and sensing, and a highly sensitive and selective non-enzymatic glucose sensor is subsequently developed for human serums with a wide linear range of 0.001–1.20 mM, low detection limit of 0.15 μM, and high sensitivity of 1181.0 μA mM−1 cm-2. It is believed that the unique structural properties of 3D Ni-N-C (abundant N-doped and Ni-N coordinated active sites, large surface area, open micro-porous structure) are conducive to the formation and exposure of highly catalytic centers and improvement of electron-transfer rate.

Amorphous Ni–Co–Fe hydroxide nanospheres for the highly sensitive and selective non-enzymatic glucose sensor applications

Among the numerous non-enzymatic sensors, transition metal or mixed-metal compounds have received considerable attention as promising electrode materials for glucose electrochemical sensors with low-cost and abundance in earth. Most researches on binary and ternary mixed metal compounds have so for been focused on the crystalline rather than the amorphous phase. In this contribution, amorphous Ni–Co–Fe hydroxide nanospheres with a homogeneous distribution of metals are fabricated directly on a graphite substrate by a novel electrochemical deposition method. The as-synthesized amorphous Ni–Co–Fe hydroxide nanosphere as an active sensing material for non-enzymatic glucose sensor exhibits a superior bio-sensing performance toward glucose oxidation with high sensitivity (1860 μA·mM−1cm−2), wide linear range (0.00025–1 mM and 1-5 mM), low detection limit (98 nM), good long-term stability and excellent selectivity in alkaline solutions. This finding greatly promotes the application of amorphous Ni–Co–Fe hydroxide nanostructures as advanced glucose electrochemical sensors materials.

Cuprous Oxide Films with Hollow Cubic Cage Structure for Nonenzymatic Glucose Detection

In this study, CuO films with hollow cubic cages were prepared by a facile two-step procedure consisting of electrodeposition synthesis and subsequent direct calcination. First, Cu2O nanocubes were fabricated on ITO substrate through a simple electrodeposition procedure. Then, Cu2O nanocubes were converted to CuO hollow cubic cages without obvious morphological change through direct calcination. The obtained CuO cubic cages serving as active materials illustrated a favorable performance for nonenzymatic glucose sensing with high sensitivity of [Formula: see text]A[Formula: see text]mM[Formula: see text][Formula: see text]cm[Formula: see text] at a low applied potential of 0.50[Formula: see text]V, fast-response time (less than 3[Formula: see text]s), low detection limit of 1.0[Formula: see text][Formula: see text]M and wide linear range up from 2.0[Formula: see text][Formula: see text]M to 1.0[Formula: see text]mM ([Formula: see text]). Moreover, the good selectivity of the CuO cubic cages-based nonenzymatic glucose sensor against electroactive compounds such as ascorbic acid, uric acid and dopamine were also demonstrated. These good features indicate that the as-prepared CuO cubic cages can be used as promising electrode materials, which have a great potential in the development of sensitive and selective nonenzymatic glucose sensors.

A sensitive and selective non-enzymatic glucose sensor with hollow Ni-Al-Mn layered triple hydroxide nanocomposites modified Ni foam

Hollow Ni-Al-Mn triple layered hydroxide (HLTH) nanocomposite is used for developing a sensitive nonenzymatic electrochemical glucose sensor. Electrochemical studies of HLTH modified nickel foam (NF) possess a remarkable sensing activity towards glucose oxidation with a wide range of detection from 0.015 mM to 8 mM. The sensors show a superior sensitivity of 2.253 mA mM−1 cm−2 with a low glucose detection limit of 1.49 μM (S/N = 3). The fast response time of electrode is <3 s was mainly attributed to the combined effects of metal ions results in the enhanced electrical conductivity of material originating from abundant electroactive cites and stable structure. The application of sensor in glucose detection from human serum is also confirmed. HLTH possess an excellent selectivity of glucose over ascorbic acid and uric acid. The fabricated sensor confirmed the suitable stability, better reproducibility, and extreme sensitivity. The proposed material can be effectively used to detect glucose level in real time application.

A Sensitive and Selective Non-Enzymatic Glucose Sensor based on AuNPs/CuO NWs-MoS2 Modified Electrode

In recent years, copper-based nanomaterials have been widely used in the study of glucose sensors because of its high sensitivity. In this work, a sensitive and selective electrochemical enzyme-free glucose sensor was successfully constructed using a composite of copper oxide nanowires (CuO NWs), molybdenum disulfide (MoS2) and gold nanoparticle (AuNPs). This composite was systematically characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The sensor performance and interface property of the Au electrode modified by NF/AuNPs/CuO-MoS2 were measured by cyclic voltammetry (CV) and chronoamperometric measurements(i-t). Under optimal condition, the proposed sensor shows sensitivity value of 872.71 μA cm−2 mM−1 for glucose, with detection range from 0.5 μM to 5.67 mΜ and detection limit of 0.5 μM. The study also confirms satisfactory selectivity, reproducibility, and stability of the constructed sensor. This NF/AuNPs/CuO NWs-MoS2 sensor performance toward normal human serum spiked with glucose is determined with RSD less than 4.71%, indicating superior potential for the practical quantitative analysis of glucose in serum samples.

Ultrasensitive and selective non-enzymatic glucose detection based on pt electrode modified by carbon nanotubes@ graphene oxide/ nickel hydroxide-Nafion hybrid composite in alkaline media

A new enzymeless glucose sensor has been fabricated and its electrocatalytic oxidation has been investigated in alkaline medium directly on the Pt Electrode modified by Activated carbon nanotubes @ graphene oxide/ nickel hydroxide-Nafion hybrid composite (PtACNT@GONHNPsNf). Under the optimized condition, the calibration curve is linear in the concentration range of 5-1100 µM using cyclic voltammetric method. The detection limit and sensitivity are 0.75 µM and 40 nA, respectively. The glucose sensor can be renewed easily in a reproducible manner by a simple polishing step and it has a long operational lifetime and short response time t90% < 1 s. In addition, the fabrication of Pt with nafion and nickel hydroxide powder was employed to eliminate the interference of ascorbic acid during the catalytic oxidation of glucose. The biosensor was used for determination of glucose in human blood serum and the oxidant with satisfactory results.

An improved sensitive and selective non-enzymatic glucose biosensor based on PEG assisted CuO nanocomposites

Determination of glucose is of enormous importance in the fields of biological, environmental and clinical analyses. In recent years, polymer modified metal oxides arrived a great consideration in the detection of glucose. In this study, we have developed a sensitive and selective non-enzymatic glucose sensor by using CuO NMO encapsulation with PEG (poly ethyleneglycol) nanocomposites. The loading content of PEG was incorporated with CuO by weight percentage (wt = 2, 4 & 6%). The fabricated CuO/PEG nanocomposites was utilized as a glucose sensor, it exhibit the tremendous electrocatalytic performances on oxidation of glucose. The electrocatalytic activity enhances with increasing the loading of PEG content. The sensor shows a low detection limit of 0.25 µM with a sensitivity of 113.8 µA mM-1 cm-2, good selectivity and stability. The CuO/PEG nanocomposites are hopeful for the advancement of cost-effective non-enzymatic glucose biosensors.

Sensitive and selective non-enzymatic glucose detection using electrospun porous CuO–CdO composite nanofibers

Porous CuO–CdO nanofibers with mean diameter of 463 nm and high surface-to-volume ratio were prepared by impregnating electrospun carboxylic-functionalized poly(arylene ether ketone) (PCA-PAEK) nanofibrous webs with metal acetate solution and subsequent calcination. The special morphology was demonstrated to be decided by ion exchange reaction between metal ions and functional groups on polymer. TGA and EDX analysis confirmed that Cd2+ was more readily to react with PCA-PAEK than Cu2+, and the amount of Cu2+ can be decreased by overloading of Cd2+, leading to the degradation of sensing performance. FT-IR proved the existence of the ion exchange reaction and demonstrated the products were highly pure CuO–CdO compounds with EDX and XRD spectra. The products detailedly investigated for direct electrocatalytic oxidation of glucose evaluated cyclic voltammetry and chronoamperometry. CuO–CdO nanofibers modified electrodes exhibited superiorities of good anti-interference, low detection limit and fast response of glucose, attributing to the enhanced conductivity brought by CdO, good electrocatalytic activity brought by CuO and large surface area brought by porous structure. The simple strategy of electrospinning porous nanofibers using PCA-PAEK as templates and combined CuO and CdO with good electrooxidation glucose functions opens a new route to generate novel conductive metal oxide hybrid nanofibers applied for glucose enzymeless sensors.

Study of the growth mechanisms of nanoporous Ag flowers for non-enzymatic glucose detection

Highly sensitive and selective non-enzymatic glucose detection was developed using nanoporous Ag flowers on a Ni substrate. The cyclic scanning electrodeposition (CSE) method was used to fabricate Ag flowers on a Ni substrate in an alkaline electrolyte. The nanoporous Ag flowers were then formed by repeated CSE in NaOH. The growth mechanisms of the nanoporous Ag flowers were systematically studied, and these mechanisms can be extended to the formation of other metal, bimetal or metal oxide. The synthesized three-dimensional nanoporous Ag flowers on the Ni substrate were used in the electro-oxidation of glucose, demonstrating a wide linear range (0.1 μM to 1 mM), fast response time (<2 s), low detection limit of 0.1 μM (S/N = 3) and a high sensitivity to detect glucose in the presence of uric acid (UA) and ascorbic acid (AA) at the level of their physiological concentrations. Apart from the nanoporous Ag flowers, the formation of a NiO thin layer on the Ni substrate during CSE also contributed to the high selectivity. This work indicates the potential for developing a fast, sensitive, selective and stable electrochemical sensor for diabetes diagnosis.

Opto-chemical glucose sensing over NiO/polyaniline hybrid matrix using optical fiber approach

The fabrication of enzyme free bio-electrode for sensitive and selective detection of different bio molecules like glucose is an essential need for biomedical laboratory and food processing industries. In this context present paper reports an efficient sensitive and selective non-enzymatic optical glucose sensing over nickel oxide encapsulated polyaniline (NiO/PANI) coated optical fiber opto-electrode. The NiO/PANI was prepared by polymerisation of in situ functionalized aniline in the presence of NiO using ammonium per sulphate. Thus, obtained NiO/PANI composite has been characterization by scanning electron microscopy (SEM), x-ray diffraction (XRD) and infrared spectroscopy (FT-IR).The catalytic behavior of prepared optode for direct oxidation of glucose at biological pH of blood serum was estimated under optimized conditions. The result reveals that developed enzyme less sensor exhibited significantly improved performance for glucose analysis than its constituents in wider linear sensing range (from 20 to 400 ppm) and n low detection limit of 5 ppm. The further, favorable reproducibility and long-term performance stability were observed for about 60 days.

Influence of mesoporous defect induced mixed-valent NiO (Ni2+/Ni3+)-TiO2 nanocomposite for non-enzymatic glucose biosensors

An extraordinary sensitive and selective non-enzymatic glucose sensor has been demonstrated based on the electrochemically highly stable NiO-TiO2 mixed oxide comprising the defect induced mesoporous TiO2 nanoparticles with Ni2+ and Ni3+ ions scattered on the surface. The defects on TiO2 nanoparticles have been successfully introduced using NiO to investigate the interfacial properties between NiO and TiO2. This defect induced interfacial behavior was characterized using X-ray diffraction, X-ray photoelectron spectroscopy and high-resolution transmission electron microscopy analyses. The obtained mixed oxide NiO-TiO2 nanocomposite dispersion was drop casted on glassy carbon electrode to form a NiO-TiO2/GCE modified electrode for non-enzymatic glucose sensor. The defects along with high surface area of mixed oxide enabled excellent electrocatalytic activity for glucose oxidation with sensitivity of 24.85 μA mM−1 cm−2 and detection limit of 0.7 μM (S/N = 3). The Ni ions scattered on the surface of TiO2 nanoparticles, enabling effective charge transfer process, circumventing the agglomeration during prolonged detection, and resulting the unprecedented long-term stability and sensitivity. Thus, this defect induced mesoporous metal oxide nanocomposite is an outstanding candidate for application as redox active material in electrochemical biosensors.

Ultrasensitive and selective non-enzymatic electrochemical glucose sensor based on hybrid material of graphene nanosheets/graphene nanoribbons/nickel nanoparticle

A fast, highly sensitive and selective non-enzymatic electrochemical glucose sensor based on graphene sheet/graphene nanoribbon/nickel nanoparticles (GS/GNR/Ni) hybrid material modified electrode was fabricated. The hybrid material was synthesized via facile in-situ chemical reduction and characterized by X-ray diffraction, transmission electron microscopy, Raman spectroscopy, cyclic voltammetry and electrochemical impedance spectroscopy. The GS/GNR/Ni/GCE showed high electrochemical activity towards the oxidation of glucose in a 0.1M NaOH solution. At an applied potential of +0.5V, it displayed wide linear amperometric response towards glucose from the range of 5nM–5mM, with a detection limit of 2.5nM and sensitivity of 2.3mA/mMcm2. Moreover, the modified electrode was relatively insensitive to commonly interfering species such as dopamine, ascorbic acid, sucrose, uric acid and Cl− ions. The fabricated sensor with better reproducibility, good long term stability, makes it a promising electrode for the development of effective glucose sensor.