Efficient Non-enzymatic Glucose Sensor Research Articles

Synthesis of CuO NRs Using a Double Hydrothermal Method for a Highly Efficient Nonenzymatic Glucose Sensor

CuO NRs electrodes as nonenzymatic glucose sensors were successfully synthesized using a simple low-cost, high-benefit (double hydrothermal method) on indium tin oxide glass CuO/ITO with different concentrations. X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), energy–dispersive X-ray spectroscopy (EDX), ultraviolet–visible spectroscopy, and investigations were used to confirm the nanostructures. XRD patterns of CuO explained all of the peaks may be attributed to CuO’s monoclinic phase. FE-SEM presented nano rod-like shapes with a diameter range of 20–100[Formula: see text]nm and was found to be uniformly and vertically grown on the ITO substrate. Besides, the energy gap of the CuO NRs was expanded to 3.3[Formula: see text]eV, 3.1[Formula: see text]eV and 3[Formula: see text]eV, respectively. CuO NRs displayed the high activity of glucose sensing, with a sensitivity of (5805.7, 7365.7 and 994.8) [Formula: see text]A[Formula: see text]Mm[Formula: see text][Formula: see text]cm[Formula: see text] with LOD (0.44, 0.4 and 0.35) [Formula: see text]A, respectively. These results indicate that the sensor has a lot of potential for becoming a high-performance nonenzymatic glucose sensor with a simple, low-cost, and unique sensor design.

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.

Binder free 3D core–shell NiFe layered double hydroxide (LDH) nanosheets (NSs) supported on Cu foam as a highly efficient non-enzymatic glucose sensor

Rational design with fine-tuning of the electrocatalyst material is vital for achieving the desired sensitivity, selectivity, and stability for an electrochemical sensor. In this study, a three-dimensional (3D) hierarchical core–shell catalyst was employed as a self-standing, binder-free electrode for non-enzymatic glucose sensing. The catalyst was prepared by decorating the shell of NiFe layered double hydroxide (LDH) nanosheets (NSs) on the core of Cu nanowires (NWs) grown on a Cu foam support. The optimized 3D core–shell Cu@NiFe LDH sensor demonstrated higher sensitivity (7.88 mA mM-1cm−2), lower limit of detection (0.10 µM) and wider linear range (1 µM to 0.9 mM) in glucose sensing with a low working potential (0.4 V). The applied sensor also showed excellent stability, reproducibility, interference ability as well as practicability in real environment. The detection of real samples further suggests its great feasibility for practical applications. The superior electrocatalytic performance is collectively ascribed to the excellent electro-conductivity of the Cu substrate, the distinct self-standing 3D porous nanostructure, the ultrathin homogenous architecture, and the appropriate loading amount of NiFe LDH NSs. This study then provides a non-enzymatic glucose sensor with 3D Cu@NiFe LDH electrode for ultrahigh sensitivity and stability.

Bimetallic Layered Hydroxide Nitrate@Graphene Oxide as an Electrocatalyst for Efficient Non-Enzymatic Glucose Sensors: Tuning Sensitivity by Hydroxide-Regulated M2(OH)4–n(An–) Phases Derived from Solvent Engineering

Bimetallic Layered Hydroxide Nitrate@Graphene Oxide as an Electrocatalyst for Efficient Non-Enzymatic Glucose Sensors: Tuning Sensitivity by Hydroxide-Regulated M₂(OH)_4–<i>n</i>(A^<i>n</i>–) Phases Derived from Solvent Engineering

Facial synthesis of highly efficient non-enzymatic glucose sensor based on vertically aligned Au-ZnO NRs

Scheme 1. Schematic illustration of the preparation and fabrication of ZnO NRs on the FTO electrode, followed by Au nanoparticle’s deposition for glucose sensing. Scheme 2. The schematic illustration of conversion of glucose into gluconolactone by using fabricated Au-ZnO NRs electrode. The preparation and fabrication of sensitive non-enzymatic electrochemical sensor based on ZnO NRs grown on the electrode surface by hydrothermal method while maintain the surface morphology of the nanorods was a challenge with high surface area and good sensing capacity. Herein we prepare vertically aligned ZnO NRs on FTO surface and decorated with Au nanoparticles for efficient non-enzymatic glucose sensor. The Au-ZnO NRs were characterized by Scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Energy Dispersive X-Ray (EDX), and electrochemical methods. The unique hexagonal Au-ZnO NRs possessed high surface area with enhanced electrochemical features for glucose oxidation. The Au-ZnO NRs have excellent linear range up to 15 mM, low detection limit (LOD) of 0.12 μM and high sensitivity of 4416 μA mM −1 cm −2 . The Au-ZnO NRs also possessed good stability, repeatability, selectivity, and reproducibility with practical application for glucose sensing in real samples. The excellent potential of Au nanoparticles decorated on ZnO NRs towards glucose detection provides new platform for fabrication of glucose detecting devices.

Deep eutectic solvents synthesis of perovskite type cerium aluminate embedded carbon nitride catalyst: High-sensitive amperometric platform for sensing of glucose in biological fluids

In the present work, a novel method for the green synthesis of CeAlO3 (CAO) polycrystalline powder through deep eutectic solvents (DES) was carried out by hydrothermal method. The carbon nitride (CN) was synthesized directly by fractional thermal polymerisation process. The combination of CeAlO3 with CN provides an excellent sensing platform for developing highly sensitive and stable electrocatalyst for non-enzymatic glucose (GLU) oxidation. The structural, morphological and electrochemical analysis of CeAlO3/CN (CAO/CN) shows the successful synthesis without any impurities. The synergistic effects of pyridinic-N, pyrrolic-N and graphitic-N are highly influencing and playing a prominent role in sensory performances of the prepared CAO/CN nano-electrocatalyst towards GLU sensing. The limit of detection (LOD) at CAO/CN modified glassy carbon electrode (CAO/CN/GCE) was calculated to be 0.86 nM in the linear concentration range of 0.01–1034.5 µM by amperometric method. The anti-interference, reproducibility, repeatability and stability analysis suggest the promising performance of the fabricated electrode towards GLU detection. The real time application of CAO/CN/GCE was evaluated towards GLU sensing in human blood, saliva and sweat, a satisfactory result was obtained. Therefore, the CAO/CN/GCE has a great application prospect as a highly efficient catalyst material for highly sensitive and efficient non-enzymatic glucose sensor.

In-situ growth of porous CoTe2 nanosheets array on 3D nickel foam for highly sensitive binder-free non-enzymatic glucose sensor

The combination of transition-metals with chalcogens provide a platform for developing highly sensitive and stable electro-catalyst materials possessing excellent electrochemical features regarding glucose oxidation. The growth of porous cobalt telluride (CoTe2) nanosheets (NSs) on a three-dimension (3D) nickel foam (NF) scaffold via anion-exchange transformation is achieved by employing low temperature scalable hydrothermal process. Being an active catalyst material for glucose detection, the CoTe2 NSs/NF electrode demonstrates an ultra-prompt response time of 0.1 s, boosting sensitivity of 168000 μA mM−1 cm−2, low limit of detection of 0.59 μM along with excellent anti-interference ability and favorable stability. Besides, the effective electrochemical performance of sensing electrode is recognized with respect to the glucose detection in real human blood serum. Overall, this material guarantees free-standing 3D architecture, interconnected porous NSs morphology, large specific surface area, high conductivity, and appealing electro-catalytic activity. Therefore, the porous CoTe2 NSs/NF binder-free electrode has a great application prospect as a promising biomimetic catalyst material for highly sensitive and efficient non-enzymatic glucose sensor.

Nitrogen-doped carbon dodecahedron embedded with cobalt nanoparticles for the direct electro-oxidation of glucose and efficient nonenzymatic glucose sensing

Developing high-performance sensors for glucose detection is extremely desirable for clinical diagnostics and life sciences. Particularly, it is greatly attractive to exploit composite materials with large surface area, doped heterojunction and non-precious metal as highly active electro-catalysts for nonenzymatic glucose sensing. Herein, we reported a N-doped carbon dodecahedron embedded with Co nanoparticles (Co@NCD) for the direct electro-oxidation of glucose and efficient nonenzymatic glucose detection. Co@NCD was synthesized by the pyrolysis of zeolitic imidazolate framework (ZIF). Field emission scanning electron microscope, high-resolution transmission electron microscope, powder X-ray diffraction, X-ray photoelectron spectroscopy and nitrogen adsorption-desorption experiments were performed to investigate Co@NCD. A well-defined dodecahedron morphology with uniform size and shape was observed. Besides, the original framework was carbonized after pyrolysis leading to a hollow and porous graphite dodecahedron containing N-doped carbon heterojunction. Moreover, Co nanoparticles were evenly distributed into the dodecahedron. With porous structure, N-doped carbon and embedded Co nanoparticles, Co@NCD displayed a notable electro-catalysis towards the direct oxidation of glucose (onset potential: 0.20 V). By using Co@NCD as electro-catalyst, an efficient nonenzymatic glucose sensor was obtained with a rapid amperometric response (within 1 s), low detection limit (0.11 μM) and broad detection range (0.2 μM–12.0 mM). In addition, remarkable selectivity, repeatability, reproducibility and long-term stability were also observed. Finally, Co@NCD prepared sensor was also successfully applied to the detection of glucose in human serum. Our results suggested that ZIF templated method could be an innovative solution for active composite catalysts in biomolecular electro-catalysis and Co@NCD prepared sensor could be a substantial preferable sensing platform for the nonenzymatic glucose detection.

New Bi2MoO6 nano-shapes toward ultrasensitive enzymeless glucose tracing: Synergetic effect of the Bi-Mo association

In a novel approach, an efficient non-enzymatic glucose sensor based on pure phase of aurivillius bismuth molybdate (BM or γ-Bi2MoO6) mixed metal oxides is reported. Three BM samples were synthesized, with/without l-cysteine (Cys) and dodecylamine (DDA) as additives, leading to different shapes: bullet (BM-C), confetti (BM-2Cys) and candy (BM-2DDA). The morphology and purity of the structures were confirmed by FE-SEM images and XRD. In order to investigate the sensor application, the samples were integrated on reduced graphene oxide and incorporated into simple and inexpensive glassy carbon electrode (GCE) without using any polyvinylpyrrolidone (PVP) or Nafion. To perform cyclic voltammetry experiments, all three biosensors were measured in PBS solution (pH = 7) in ±1.5 voltage range and 50 mV s−1 scan rate. Glucose identification by the synthesized composites is an obvious sign of their high efficiency. According to chronoamperomograms, the best sensitivity of 3050 μA L mmol−1 cm−2 with linear range of 0.02–0.14 mmol L−1, low detection limit (LOD) of 0.004 mmol L−1 and the signal/noise equal to 3 was achieved by BM-2DDA/rGO/GCE biosensor and its speedy amperometric response is less than 5 s. This biosensor showed impressive selectivity, repeatability and reproducibility results besides it maintains its stability considerably in great percentage of 98.5% after eight weeks. Also it showed prolonged stability after 50 min.

Construction of highly efficient non-enzymatic glucose sensors based on micro-spherical Ni-metal-organic frameworks

The Ni-metal-organic frameworks microspheres (Ni-BTC) were prepared and used directly to construct non-enzymatic glucose sensors. The Ni-BTC sensors displayed much higher glucose sensing performance than that of Ni-MOFs derived NiO, which showed wide detection regions of 5–3000[Formula: see text][Formula: see text]M and 3500–6000[Formula: see text][Formula: see text]M with the sensitivity of 932.68[Formula: see text][Formula: see text]A[Formula: see text]mM[Formula: see text]cm[Formula: see text] and 273.04[Formula: see text][Formula: see text]A[Formula: see text]mM[Formula: see text]cm[Formula: see text], respectively. Moreover, it also displayed good selectivity and favorable sensing feasibility for serum analysis. The high performance of the non-enzymatic glucose detection on Ni-BTC may be due to the highly efficient charge transfers during the electrocatalytic glucose oxidation process.

Efficient Nonenzymatic Sensors Based on Ni-MOF Microspheres Decorated with Au Nanoparticles for Glucose Detection

Au nanoparticles were decorated on Ni-based metal–organic frameworks to improve their electrochemical performance for nonenzymatic glucose detection through a convenient and fast microwave-assisted process. Various techniques including scanning electron microscopy, transmission electron microscopy, X-ray diffraction, energy dispersive X-ray mapping and X-ray photoelectron spectroscopy were used to characterize the Au@Ni-BTC composites. The results revealed that Au nanoparticles were uniformly deposited on the Ni-BTC microspheres. The constructed Au@Ni-BTC sensors showed highly increased glucose detection performance with a wide linear range (5–7400 μM), high sensitivity (1447.1 μA mM−1 cm−2) and low detection limit (1.5 μM). Moreover, they also exhibited good selectivity and preferable feasibility for serum sample analysis. The improved glucose sensing performance may be due to the synergistic effects of Au nanoparticles and Ni-BTC, which facilitated faster charge transfer in the electrochemical process. The study of Au@Ni-BTC may also provide a promising material for constructing highly efficient nonenzymatic glucose sensors.

Ni Hierarchical Structures Supported on Titania Nanowire Arrays as Efficient Nonenzymatic Glucose Sensor.

Developing new advanced nonenzymatic electrochemical nano-sensors for glucose detection has attracted intensive attraction. In this work, we designed a novel nanocomposite nonenzymatic glucose sensor by fabricating hierarchically nanostructured metal nickel on titania nanowire arrays, which was loaded on a transparent conductive substrate (i.e., fluorine-doped tin oxide, FTO) surface by mild hydrothermal method. Due to the large surface area of the hierarchically nanostructured Ni and fast electron transfer of the TiO₂ nanowire arrays electrode, the nanocomposite electrode shows excellent electrochemical activity toward the oxidation of glucose. The electrode exhibits high sensitivity in detecting glucose concentration (1472 μA mM-1 cm-2) with a wide linear range from 2×10-4 M to 2×10-3 M, fast response time (within 5 s), and small detection limit (10 μM) (S/N = 3). The good analytical performance, low cost and simple preparation method make this novel electrode material promising for the development of effective glucose nonenzymatic glucose sensor.

Highly efficient non-enzymatic glucose sensor based on CuxS hollow nanospheres

Copper sulfide with copper to sulfur stoichiometric ratios of 2:1, 2.5:1 and 3:1 is rapidly synthesized by varying the amount of sulfur precursor against Cu2O nanospheres. The size, morphology, crystalline nature, and elemental compositions of CuxS hollow nanospheres such as, CuS, Cu2S, Cu7S4, and Cu2O are characterized by using transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction analysis (XRD) and X-ray photoelectron spectroscopy (XPS) techniques. The synthesized CuxS hollow nanospheres display a substantial electrocatalytic activity towards the oxidation of glucose in alkaline medium. Notably, the Cu7S4 hollow-like nanospheres exhibited highest glucose sensitivity of 3728.7 μA mM−1 cm−2 as compared to the other CuxS hollow nanospheres. Further, the Cu7S4 hollow nanospheres show a wide linear concentration responses towards the oxidation of glucose from 1.0 μM to 2.0 mM, with a limit of detection (LOD) of 0.023 μM (S/N = 3). The obtained results indicate that Cu7S4 hollow nanospheres as a promising candidate for non-enzymatic glucose sensing.

Highly efficient nonenzymatic glucose sensors based on CuO nanoparticles

In this work, copper nanoparticles using three different modes are synthesized and evaluated for electrochemical properties towards non-enzymatic glucose biosensors. Copper oxide nanoparticles thus obtained are characterized using X-ray diffractometer (XRD), Scanning Electron Microscope (SEM), transmission electron microscopy (TEM) and UV–Vis for their crystallinity, morphology and optical properties. The nanoparticles obtained using colloidal method (Cu-Colloid) give uniform phase of CuO and flower shaped morphology. The nanoparticles synthesized using solution combustion method with glycine (Cu-Gly) and hydrazine (Cu-Hyd) as fuel provide particles of irregular round shape and small flake-like structures respectively. The glucose electro oxidative current is highest for Cu-Colloid catalysts and could be due to the higher area of contact of the catalyst surface with the glucose. Cu-colloid particles with flower shaped morphology give wide linear response in the range of 1 μM to 850 μM along with the lowest limit of detection of 0.25 μM and highest sensitivity of 2062 μA mM−1 cm−2. Cu-Colloid catalyst show poor response on the presence of co-existing species on the blood sample when compared to its sensitivity towards glucose. The time response of Cu-Colloid particles for glucose detection is the least when compared to other two nanoparticles. Also, the Cu-Colloid particles show excellent reproducibility and stability that makes it a promising electrode for the non-enzymatic glucose bio-sensors.

Interfacial Effect of Oxygen-Doped Nanodiamond on CuO and Micropyramidal Silicon Heterostructures for Efficient Nonenzymatic Glucose Sensor.

Herein, the novel strategy of copper oxide (CuO) deposited oxygen-doped nitrogen incorporated nanodiamond (NOND)/Si pyramids (Pyr-Si) heterostructure is studied for high-performance nonenzymatic glucose sensor. The combined properties of surface-modified NOND/Pyr-Si induced by different growth durations (5 to 20 min) of CuO is envisioned to improve glucose sensitivity and stability. For comparison, the same methods and parameters were deposited on the plane silicon wafers. The systematic analysis reveals the best glucose sensing properties of 15 min grown CuO/NOND/Pyr-Si based sensor, with a high sensitivity of 1993 μA mM-1 cm-2, a lower limit of detection of 0.1 μm, and a longer stability of 28 d (∼96%). In addition, the present sensor exhibits good selectivity of glucose among other analytes such as sodium chloride, ascorbic acid, uric acid, and so on. The enhancement in glucose sensing performances of the as-fabricated CuO/NOND/Pyr-Si is ascribed to the interfacial effect of NOND and the synergistic effect of CuO and NOND/Pyr-Si. Moreover, the oxygen dopant in NOND and CuO stimulates the reactive oxygen species while measuring glucose and affords rapid recovery (<2 s). This promotes fast electron kinetics in the electrocatalytic solutions, which enhances the electroactive area and thereby contributes to a high sensitivity. These salient results suggested that the as-fabricated CuO/NOND/Pyr-Si sensor is more suitable for high-performance biosensors and effective energy storage device applications.

Highly Efficient Non-Enzymatic Glucose Sensor Based on CuO Modified Vertically-Grown ZnO Nanorods on Electrode

There is a major challenge to attach nanostructures on to the electrode surface while retaining their engineered morphology, high surface area, physiochemical features for promising sensing applications. In this study, we have grown vertically-aligned ZnO nanorods (NRs) on fluorine doped tin oxide (FTO) electrodes and decorated with CuO to achieve high-performance non-enzymatic glucose sensor. This unique CuO-ZnO NRs hybrid provides large surface area and an easy substrate penetrable structure facilitating enhanced electrochemical features towards glucose oxidation. As a result, fabricated electrodes exhibit high sensitivity (2961.7 μA mM−1 cm−2), linear range up to 8.45 mM, low limit of detection (0.40 μM), and short response time (<2 s), along with excellent reproducibility, repeatability, stability, selectivity, and applicability for glucose detection in human serum samples. Circumventing, the outstanding performance originating from CuO modified ZnO NRs acts as an efficient electrocatalyst for glucose detection and as well, provides new prospects to biomolecules detecting device fabrication.

Ternary Pd–Ni–P nanoparticle-based nonenzymatic glucose sensor with greatly enhanced sensitivity achieved through active-site engineering

We develop a unique ternary Pd–Ni–P nanocatalyst for the sensitive enzymefree electrooxidation detection of glucose under alkaline conditions. By reducing the distance between the Pd and Ni active sites in the Pd–Ni–P nanoparticles (NPs) via atom engineering, the catalyst structure is transformed from Pd@Ni–P dumbbells into spherical NPs, greatly enhancing the catalyst sensitivity. The glassy carbon electrode modified with Pd–Ni–P ternary NPs, which behaves as an efficient nonenzymatic glucose sensor, offers excellent electrocatalytic performance with a high sensitivity of 1,136 μA·mM−1·cm−2, a short response time of 2 s, a wide linear range of 0.5 μM to 10.24 mM, a low limit of detection of 0.15 μM (signal-to-noise ratio = 3), and good selectivity and reproducibility. Moreover, owing to its superior catalytic performance, the Pd–Ni–P modified electrode has excellent reliability for glucose detection in real samples of human serum. Our study provides a promising alternative strategy for designing and constructing high-performance multicomponent nanocatalyst-based sensors.

Three-Dimensional Copper Foam Supported CuO Nanowire Arrays: An Efficient Non-enzymatic Glucose Sensor

Metal and metal oxides with various nanostructures have been widely studied in non-enzymatic glucose sensing. In this work, we report an efficient catalyst platform, which is made of three-dimensional copper foam (CF) skeleton and copper oxide nanowire arrays (CuONWA), is used to construct glucose sensor. The three-dimensional CuONWA/CF was synthesized via a facile wet-chemical method and subsequent annealing. The CuONWA is evenly covered by CuO nanoflowers. The morphology and composition of the platform were characterized. The nanowire arrays and nanoflowers both enhanced the electrocatalytic performance of the integrated electrode via greatly increasing the surface area of the CF substrate. The electrocatalytic properties of the non-enzymatic glucose sensor were characterized by a series of electrochemical measurements. The sensor exhibits excellent performance, with a linear range of 0.10μM–0.50mM, a sensitivity of 32330μAmM−1cm−2, a low limit of detection of 20nM (S/N=3), excellent selectivity, reproducibility, and stability. The sensor was also used for glucose sensing in human serum and Wahaha ice black tea, with relative standard deviations (for n=6) of 3.15% and 2.43%, respectively.

CuO nanothorn arrays on three-dimensional copper foam as an ultra-highly sensitive and efficient nonenzymatic glucose sensor

A novel glucose sensor based on a CuO nanothorns/Cu foam was prepared using a low-cost and facile method.

Simple Electrochemical Synthesis of Cuprous Oxide Nanoparticles and Their Application as a Non-Enzymatic Glucose Sensor

Simple, additive-free nanosynthesis using environmentally benign processes and chemicals has attracted considerable attention in recent times. Cuprous oxide nanoparticles were electrochemically deposited using a simple aqueous electrolyte solution at room-temperature in the presence of air, showing a green, template-less one-step method of electrochemical synthesis. The size and distribution of the particles can be controlled by varying the concentration of sulfuric acid electrolyte. Time of deposition can be controlled to create a uniformly deposited layer of nanoparticles. Deposition potential shows only moderate influence on the size of nanoparticles. Furthermore, it was shown that Cu2O nanoparticles can be effectively used for the fabrication of a low-cost, efficient non-enzymatic glucose sensor. Sensor shows excellent electrocatalytic activity for the electrooxidation of glucose with high sensitivity (507 μA/mMcm2) over a detection range of 100 μM to 2.5 mM. It exhibits good reproducibility and stability with a quick response time (<5 s) and good limit of detection (26 μM) for glucose.