Non-enzymatic Glucose Sensor Research Articles

Screen-printed electrochemical biosensor based on a ternary Co@MoS2/rGO functionalized electrode for high-performance non-enzymatic glucose sensing.

In this study, cobalt oxides functionalized MoS2/reduced graphene oxide was synthesized via a facile one-pot hydrothermal approach. Morphology and crystal structure of this ternary nanoarchitecture were characterized through scanning electron microscopy, transmission electron microscopy, Raman spectra and X-ray photoelectron spectroscopy. An ultrasensitive non-enzymatic glucose sensor was developed by decorating this ternary nanohybrid on the working electrode of a screen-printed electrochemical sensor. Cycle sweep voltammetry and amperometry were used to study the electro-catalytic activity of the modified working electrode, which demonstrated superior catalytic activity towards glucose oxidation with an extremely low detection limit of 30nM. Meanwhile, this sensor showed an excellent selectivity in the presence of interfering species such as uric acid, ascorbic acid, etc. Based on the screen-printed technique, enzyme mimic nanomaterials could be easily introduced into portable devices, which opens the way to take non-enzymatic glucose electrochemical sensing towards point-of-care.

Hierarchical α-Fe2O3 microcubes supported on Ni foam as non-enzymatic glucose sensor

Hierarchical α-Fe2O3 microcubes supported on Ni foam (NF) have been successfully prepared using Fe-MOF as a precursor combined with a hydrolysis process, which can be used as the electrodes directly for effective non-enzymatic glucose sensing. The structures and compositions of the as-prepared α-Fe2O3/NF electrode materials were carefully characterized by scanning electron microscopy (SEM), X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and energy dispersive spectroscopy (EDS), respectively. The α-Fe2O3/NF electrodes exhibit excellent glucose oxidation performance with a response time < 3 s and a sensitivity of 10,356 μA mM−1 cm−2. Additionally, the material shows good anti-interference sensing performance and stability for glucose detection in the presence of ascorbic acid (AA), dopamine (DA), cysteine (Cys), uric acid (UA), NaCl and other interferences. It is believed that α-Fe2O3/NF composite can act as a promising electrode material for non-enzymatic glucose sensing applications, and the materials design strategy can be also expanded for other functional systems.

Non-Enzymatic Amperometric Glucose Sensor Based on Carbon Nanodots and Copper Oxide Nanocomposites Electrode.

In this research work, a non-enzymatic amperometric sensor for the determination of glucose was designed based on carbon nanodots (C-dots) and copper oxide (CuO) nanocomposites (CuO-C-dots). The CuO-C-dots nanocomposites were modified on the surface of a screen-printed carbon electrode (SPCE) to increase the sensitivity and selectivity of the glucose sensor. The as-synthesized materials were further analyzed for physico-chemical properties through characterization tools such as transmission electron microscopy (TEM) and Fourier-transform infrared spectroscopy (FTIR); and their electrochemical performance was also studied. The SPCE modified with CuO-C-dots possess desirable electrocatalytic properties for glucose oxidation in alkaline solutions. Moreover, the proposed sensing platform exhibited a linear range of 0.5 to 2 and 2 to 5 mM for glucose detection with high sensitivity (110 and 63.3 µA mM−1cm−2), and good selectivity and stability; and could potentially serve as an effective alternative method of glucose detection.

NiCo2S4 Nanowire‐Decorated Flexible Carbon Foam for Sensitive Glucose Sensors

AbstractBinary nickel cobalt sulfide (NiCo2S4) nanostructures have attracted much attention in electrochemistry fields due to its highly catalytic activity and low cost. Herein, NiCo2S4 nanowire arrays grown on three‐dimensional carbon foam (NiCo2S4/3DCF) is presented for nonenzymatic glucose sensor. Porous NiCo2S4/3DCF with self‐supporting structure was synthesized via a self‐designed two‐step hydrothermal process, and was fabricated as flexible sensor directly without any modify treatments. The linear range of this sensor is 0.005–13.07 mM (R2 = 0.999) with detection limit of 0.5 μM (S/N=3). In addition, the as‐proposed sensor also displays other outstanding advantages, including simple of preparation, low cost, perfect reproducibility and good selectivity. Such attracting sensing properties may be due to the high electrocatalytic activity of NiCo2S4 and good electrical conductivity of 3DCF frameworks. Therefore, NiCo2S4/3DCF may show great promise in glucose sensor applications.

NiO/Cu-TCPP Hybrid Nanosheets as an Efficient Substrate for Supercapacitor and Sensing Applications

In this study, ultra-thin two-dimensional (2D) metalloporphyrinic metal-organic framework (MOF) nanosheets were grown on nickel oxide (NiO) nanoparticles; a successful synthesis of new type of hybrid nanosheets was developed. The structure and morphology of hybrid nanosheets obtained by instrumental characterization showed that a composite of 2D Cu-TCPP (tetrakis(4-carboxyphenyl)phosphonium porphyrin) MOF nanosheets and NiO nanoparticles was synthesized. The obtained hybrid nanosheets can be used in many applications including supercapacitors and electrochemical sensors for glucose detection. Compared with conventional 2D MOFs and NiO nanoparticles, hybrid nanosheets have high specific capacitance (2394 Fg−1, 5 Ag−1). The obtained hybrid nanosheets were successfully used as a glucose sensor and showed a high sensitivity of 4.6 μA μm−1 cm−2. The study shows that this new electrode material is expected to be used to develop high performance capacitors and effective non-enzymatic glucose sensors.

Core-shell gold-nickel nanostructures as highly selective and stable nonenzymatic glucose sensor for fermentation process

Non-enzymatic electrodes based on noble metals have excellent selectivity and high sensitivity in glucose detection but no such shortcomings as easy to be affected by pH, temperature, and toxic chemicals. Herein, spherical gold-nickel nanoparticles with a core-shell construction (Au@Ni) are prepared by oleylamine reduction of their metal precursors. At an appropriate Au/Ni ratio, the core-shell Au@Ni nanoparticles as a sensor for glucose detection combine the high electrocatalytic activity, good selectivity and biological compatibility of Au with the remarkable tolerance of Ni for chlorine ions (Cl−) and poisoning intermediates in catalytic oxidation of glucose. This electrode exhibits a low operating voltage of 0.10 V vs. SCE for glucose oxidation, leading to higher selectivity compared with other Au- and Ni-based sensors. The linear range for the glucose detection is from 0.5 mmol L−1 to 10 mmol L−1 with a rapid response time of ca. 3 s, good stability, sensitivity estimated to be 23.17 μA cm−2 mM−1, and a detection limit of 0.0157 mM. The sensor displays high anti-toxicity, and is not easily poisoned by the adsorption of Cl− in solution.

Nano-donuts shaped nickel oxide nanostructures for sensitive non-enzymatic electrochemical detection of glucose

In this study, we report the synthesis of nano-donut shaped nickel oxide (NiO) nanostructures using a simple low-temperature hydrothermal process. The detailed characterizations of nano-donut shaped NiO confirm that the as-synthesized nanostructures are grown in large quantity with relatively uniform morphology. Using the nano-donut shaped NiO nanostructures, the electrochemical based non-enzymatic glucose sensors were fabricated and their catalytic properties towards glucose electro-oxidation were conducted in alkaline media. The sensing results revealed the high sensitivity (904.6 µA mM−1 cm−2) and low detection limit (1.4 µM). Owing to the high glucose sensing performance, the nano-donut shaped NiO nanostructures with a unique two-dimensional morphology and high specific surface area have the potential for electrochemical sensing of other biochemical analytes.

Roles of TiO2 in the highly robust Au nanoparticles-TiO2 modified polyaniline electrode towards non-enzymatic sensing of glucose

Along with the rise of diabetes mellitus issue, glucose sensor has become an imperative tool for healthcare. Studies have been widely conducted on electrode materials for glucose sensors; metal nanoparticles and/or oxide particles in its nano-size are reported to exhibit remarkable electrocatalytic activities in the non-enzymatic glucose sensors. However, the decoration processes of metal nanoparticles or nano-sized oxides are known to be tedious and time-consuming. In addition, the processes usually result in great amount of waste solution emission. In this study, therefore, an Au nanoparticles (NPs)-TiO2 modified polyaniline (PANI) composite is practiced towards the applications of non-enzymatic glucose sensors, by using a facile and time-saving thermal reduction and by electrodeposition techniques with low waste solution emission. Au NPs, which is modified with TiO2 nanoparticles in its optimized amount, performs the highest electrocatalytic activity to the oxidation of glucose in alkaline solution. The stability of Au NPs-TiO2/PANI is superior to those of most reported results over 70 days. The sensitivity and detection limit are 379.8 μA mM−1 cm−2 and 0.15 μM, respectively. High selectivity of Au NPs-TiO2/PANI is also confirmed by the interference test. Spill-over effect of OH− between Au NPs and TiO2, which is the main reason for the improved catalytic activity, is described in this study.

Glucose sensor based on Pd nanosheets deposited on Cu/Cu2O nanocomposites by galvanic replacement

A novel non-enzymatic glucose sensor was established by galvanic replacement synthesis of Pd nanosheets (PdNS) on Cu/Cu2O nanocomposites using fluorine-doped tin oxide (FTO) substrates. To prepare PdNS-Cu/Cu2O/FTO electrode, Cu/Cu2O nanocomposites were firstly deposited on FTO electrode through potential oscillating, and then Pd nanosheets were synthesized on Cu/Cu2O nanocomposites by galvanic replacement reduction. X-ray diffraction, scanning electron microscopy, transmission electron microscopy and X-ray photoelectron spectroscopy were applied to investigate the morphology and composition of PdNS-Cu/Cu2O nanohybrids. The synthesized PdNS-Cu/Cu2O exhibited great electrochemical activity toward glucose oxidation. Under optimized conditions, the proposed glucose sensor displayed a wide linear range from 0.5 μM to 2600 μM with detection limit of 0.1 μM. In addition, the proposed electrode was used to determine glucose in true blood specimen, indicating potential application for routine glucose analysis.

CuO/Cu composite nanospheres ona TiO2 nanotube array for amperometric sensing of glucose.

A non-enzymatic glucose sensor based on the use ofCuO-Cunanospheres placed on aTiO2 nanotube (TNT) array with excellent performance is described. The electrode was fabricated by coating the CuO-Cu nanospheres onto the TNTarray through electrochemical deposition. TheCuO-Cu nanospheres with a diameter of ~200nm are well dispersed onthe TNT surface, which warrants smooth interaction and a 3D nanostructure with high uniformity. The modified electrode was then used for amperometric determination of glucose in 0.1M NaOH solution. Figures of merit include (a) a typical working voltage of 0.65V (vs. Ag/AgCl). (b) a linear range as wide as from 0.2-90mM, (c) good sensitivity (234μAmM-1cm-2), and a 19nM lower detection limit. The sensor is selective over ascorbic acid (AA), dopamine (DA), uric acid (UA), lactose, sucrose, and fructose. Graphical abstract.

Ultrathin CuxO nanoflakes anchored Cu2O nanoarray for high-performance non-enzymatic glucose sensor

Designing highly active material to fabricate high-performance glucose sensor was great importance for diabetes treatment. In this work, we develop a novel nanocomposite composed of multilevel nanostructure with ultrathin CuxO nanoflakes anchored on Cu2O nanowires, directly on Cu foil and its application as non-enzymatic glucose sensor. Due to more active sites endowed by the ultrathin CuxO nanoflakes, the as-prepared CuxO nanoflakes/Cu2O nanowires@Cu nanoarray exhibit high sensitivity (3.59 mA mM−1 cm−2), low detection limit (0.69 μM), high selectivity, fast amperometric response (~ 2 s) and excellent reliability in human serum. And the sensitivity of ultrathin CuxO nanoflakes/Cu2O nanowires@Cu nanoarray was 1.9-fold than that of Cu2O nanowires@Cu nanoarray. Such novel multilevel nanoarray synthesized by convenient method provides a facile way to design metal oxide nanomaterial for promising non-enzymatic glucose sensor.

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.

High sensitive polyaniline nanosheets (PANINS) @rGO as non-enzymatic glucose sensor

This study aims the amperometric enzyme-free glucose sensing of interlayered Polyaniline nanosheets @reduced grapheme oxide (PANINS@rGO). Conductive PANINS were synthesized using in situ chemical oxidative polymerization method. The PANINS@rGO nanocomposite was prepared by the solution mixing method and as-synthesized material was fully examined using various spectroscopy and microscopy techniques. PANINS@rGO composite coated on screen-printed carbon electrode (SPCE) was studied for electrochemical behaviour for the detection of non-enzymatic glucose. The fabricated sensor matrix was tested towards detection of glucose efficacy using cyclic voltammetry (CV) and Chronoamperometry (CA) techniques in the presence of 0.1 M NaOH electrolyte in a range of 1–10 mM at an optimum working potential of 60 mV s−1. PANINS@rGO/SPCE absorbed with high sensitivity (3448.27 μA mM−1 cm−2) and excellent low detection limit (LOD) 30 nM, (S/N = 3). Furthermore, the obtained results of the proposed PANINS@rGO/SPCE fabricated a finite sensor for non-enzymatic glucose sensor. Thus this report proves the practical opportunities for the development of environmentally benign, cost effective and chemically stable electrode materials for sensors, which may be beneficial for the expansion of economically viable enzyme free electrochemical glucose sensor devices.

Role of Transition Metals in Layered Double Hydroxides for Differentiating the Oxygen Evolution and Nonenzymatic Glucose Sensing.

Layered double hydroxides (LDH) belong to the class of two-dimensional materials having a wide variety of applications ranging from energy storage to catalysis. Often, these materials when used for nonenzymatic electrochemical glucose sensing tend to be interfering with oxygen evolution reaction (OER), resulting in overestimation of the glucose. Herein, to address this, NiFe-based LDH were selected because of their ability to vary the metal ratios. The synthesized LDH have been characterized using various spectroscopic and microscopic techniques. Among the LDH synthesized, Ni4Fe-LDH have been able to differentiate the glucose oxidation potential and the onset potential of OER with minimum interference. The Ni4Fe-LDH sensor shows a sensitivity of 20.43 μA mM-1 cm-2 in the linear range of 0-4 mM concentrations. To further enhance the sensitivity, composites of reduced graphene oxide (rGO) have been synthesized in situ, and the Ni4Fe/rGO5 composites have shown an increased sensitivity of 176.8 μA mM-1 cm-2 attributed to the charge-transfer interactions. To understand the experimental observations, detailed computational studies have been carried out to study the effect of the electronic structure on the metal ratios of the LDH and its role in differentiating glucose sensing and the oxygen evolution reaction. Along with this, theoretical calculations are also carried out on LDH-graphene composites to study the charge-transfer interactions.

A graphite pencil electrode with electrodeposited Pt-CuO for nonenzymatic amperometric sensing of glucose over a wide linear response range.

A disposable nonenzymatic glucose sensor was obtained by pulsed electrodeposition of Pt-CuO on a graphite pencil electrode (GPE). The morphology of the modified GPE was studied using SEM, and the chemical composition of the coating was examined by EDAX and XRD. The electrochemical response of the modified GPE was compared with individual copper- and platinum-modified GPEs. The electrodeposition parameters were optimized with respect to the electrocatalytic activity of the deposits towards glucose oxidation. Best operated at a working potential of 0.6V vs. Ag/AgCl, the sensor has a sensitivity of 2035μAmM-1cm-2, a 0.1μM detection limit and a wide linear response range that extends up to 25mM. It is highly selective for glucose in the presence of various exogenous and endogenous interfering species. Eventhough the requirement of alkaline medium for sensing is a limitation, easy fabrication procedure, very high sensitivity and selectivity, wide analytical range, and disposable sensor characteristics show potential application towards blood glucose determination. Graphical abstractSchematic representation of the Pt-CuO electrodeposited pencil graphite electrode for the nonenzymatic determination of glucose.

Controllable Synthesis of Ni/Co-TCPP MOFs with Different Morphologies and Their Application in Electrochemical Detection of Glucose

In this work, a series of Ni/Co-TCPP (tetrakis(4-carboxyphenyl)phosphonium porphyrin) MOFs (metalloporphyrinic metxal-organic framework) were controllably synthesized by adjusting the ratio of Ni/Co and solvent volume. The results showed that the morphologies of sheet-like, film-like, flower-like and rod-like morphologies of Ni/Co-TCPP MOFs were successfully synthesized. The obtained Ni/Co-TCPP MOFs-1 were used as electrochemical sensors for glucose detection. The sensor showed a high sensitivity of 2.8 mA mM−1 cm−2, fast response time (about 5 s), a low detection limit of 0.3 μM (S/N = 3), and wide linear range of 1.0 μM to 3.8 mM. It shows that the obtained Ni/Co-TCPP MOFs may be expected to be used to develop effective non-enzymatic glucose sensors.

Annealing temperature regulating the dispersity and composition of nickel-carbon nanoparticles for enhanced glucose sensing

Design of electrodes with both excellent electrocatalytic activity and facile synthesis process is the pivotal challenge in the progress of non-enzymatic glucose sensors. In this work, a series of highly dispersed nickel-carbon nanoparticles modified boron doped diamond composite electrodes were fabricated after the boron doped diamond films with a sputtering nickel layer being annealed at different temperature in hydrogen atmosphere. The surface morphology and interface structure of nickel-carbon nanoparticles modified boron doped diamond samples were characterized detailedly with the increase of annealing temperature. The charge transfer of synthesized electrodes was improved with the increasing content of sp2 carbon and the improvement of crystallinity of nickel. Therefore, the volcano-type electrocatalytic performance trend was observed with the composite electrode prepared after annealing at 500 °C presenting the best glucose sensing performance with the sensitivities of 1730 and 1081 μA cm−2 mM−1 in glucose concentration ranges of 0.01–2.12 and 2.12–9.06 mM respectively and a low detection limit of 0.2 μM (S/N = 3).

A highly sensitive non-enzymatic glucose sensor based on CuS nanosheets modified Cu2O/CuO nanowire arrays

CuS nanosheets modified Cu2O/CuO nanowire arrays (NWAs) were successfully fabricated on Cu foil by in-situ growth and successive ionic layer adsorption and reaction (SILAR) methods without binders. The three-dimensional Cu2O/CuO NWAs not only showed strong binding force with current collector but also provided abundant surface area to support CuS nanosheets. Different morphologies of CuS were obtained by varying the Cu(NO3)2 and Na2S concentrations and the SILAR cycle. When these step-wise prepared products were employed for non-enzymatic glucose sensing, the amperometric response of the optimized CuS/Cu2O/CuO/Cu electrode was approximately twice of that of Cu2O/CuO/Cu electrode. The result is attributed to the modification of CuS nanosheets with suitable amount which increases the active surface area of the electrode. This designed electrode presents an ultrahigh sensitivity of 4262 μA mM−1 cm−2 in the range from 0.002 to 4.096 mM, as well as the excellent selectivity, reproducibility and stability. Moreover, due to the facile preparation and the low cost of Cu based sensors, the CuS/Cu2O/CuO/Cu electrode will be one kind of promising materials for constructing practical non-enzymatic glucose sensors.

Electrokinetic Carbohydrates Sensor by Streaming Potential with 3MPBA-PtNPs-CNTs Composite Material

In this work, a sensitive and highly stable non-enzymatic glucose sensor is reported. It is based on self-assembled 3-mercaptophenylboronic acid (3MPBA) self-assembled on small Pt nanoparticles supported on a multi-wall carbon nanotubes (CNTs) surface. The materials characterization was performed by thermal analysis (TGA), scanning transmission electron microscopy (STEM), X-ray diffraction (XRD), cyclic voltammetry (CV), and Z potential measurements. Glucose and fructose evaluation was carried out by hydrodynamic zeta potential measurements using the streaming potential, presenting high selectivity to glucose in the alkaline medium. The 3MPBA-PtNPs-CNTs electrode exhibit a linear response in the glucose concentration range of 0 to 10 mM, high sensitivity to 22.25 mV mM−1, and ultra-low detection of 4.5 μM.

In Situ Fabrication of Porous Nanostructures Derived from Bimetal-Organic Frameworks for Highly Sensitive Non-Enzymatic Glucose Sensors

Metal-organic framework (MOF) based porous derivatives have been attractive materials for high-performance electrochemical sensors due to their high surface-area, stability and activities. Herein, an in situ fabrication method is proposed to obtain porous Cu/Co bimetallic MOF-based derivatives on the flexible carbon cloth for glucose sensing. The process is also developed with three critical steps. Firstly, uniform Cu(OH)2 nanorods are directly formed through wet chemical method on Cu sputtered carbon cloth. Then, oriented growth of Zeolitic Imidazolate Framework-67 (ZIF-67) and ion-exchange convert the sample into Cu-Co-ZIF nanosheets. Finally, porous Cu-Co-ZIF derivatives are obtained by thermal annealing. The fabrication mechanism has been discussed through detailed characterizations of intermediate and final products. The as-obtained nanostructures with rich reaction sites and short ion diffusion path show excellent electrochemical properties for glucose sensing (high sensitivity of 18.68 mA mM-1 cm-2, fast response time of 1.5 s and low detection limit of 2 μM). This study proposes a practical fabrication strategy for bimetallic MOF-based porous nanostructures, which are promising for a wide variety of electrochemical applications.