Non-enzymatic Glucose Biosensor Research Articles

Hierarchical Co3O4/CuO nanorod array supported on carbon cloth for highly sensitive non-enzymatic glucose biosensing

A hierarchical core-shell Co3O4/CuO nanorod array (NRA) anchored on flexible carbon cloth (CC) has been fabricated through a stepwise process consisting of magnetron sputtering of Cu, its anodic oxidation, and chemical bath deposition of Co3O4. The structure, composition and morphology of the synthesized Co3O4/CuO NRA on CC were characterized by X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The glucose sensing performance of the Co3O4/CuO NRA on CC electrode was investigated by cyclic voltammetry and chronoamperometry. The sensor exhibited a high sensitivity of 5405 μA mM−1 cm−2 with a fast response time (t90 = 1.9 s) and a low detection limit of 0.38 μM. The electrode also showed outstanding selectivity toward various interferences. These results indicate that the Co3O4/CuO nanocomposites may be promising electrode materials for electrochemical biosensing.

Ultrasensitive and Highly Selective Ni3Te2 as a Nonenzymatic Glucose Sensor at Extremely Low Working Potential.

Developing Nonenzymatic glucose biosensors has recently been at the center of attention owing to their potential application in implantable and continuous glucose monitoring systems. In this article, nickel telluride nanostructure with the generic formula of Ni3Te2 has been reported as a highly efficient electrocatalyst for glucose oxidation, functional at a low operating potential. Ni3Te2 nanostructures were prepared by two synthesis methods, direct electrodeposition on the electrode and hydrothermal method. The electrodeposited Ni3Te2 exhibited a wide linear range of response corresponding to glucose oxidation exhibiting a high sensitivity of 41.615 mA cm–2 mM–1 and a low limit of detection (LOD) of 0.43 μM. The hydrothermally synthesized Ni3Te2, on the other hand, also exhibits an ultrahigh sensitivity of 35.213 mA cm–2 mM–1 and an LOD of 0.38 μM. The observation of high efficiency for glucose oxidation for both Ni3Te2 electrodes irrespective of the synthesis method further confirms the enhanced intrinsic property of the material toward glucose oxidation. In addition to high sensitivity and low LOD, Ni3Te2 electrocatalyst also has good selectivity and long-term stability in a 0.1 M KOH solution. Since it is operative at a low applied potential of 0.35 V vs Ag|AgCl, interference from other electrochemically active species is reduced, thus increasing the accuracy of this sensor.

Fabrication, characterization of polyaniline intercalated NiO nanocomposites and application in the development of non-enzymatic glucose biosensor

Determination of glucose plays very important part in diagnostics and management of diabetes. Nowadays, determination of glucose is necessary in human health. In order to develop the glucose biosensor, polymer modified catalytic composites were fabricated and used to detect glucose molecules. In this work, NiO nanostructure metal oxide (NMO) was fabricated via thermal decomposition method and polyaniline (wt% = 2, 4 and 6) assisted nanocomposites (NiO/PANI) were also prepared. The morphology and structure of synthesized nanocomposites were characterized by UV–visible diffusion reflectance spectroscopy (UV–vis-DRS), Fourier transform- infra red spectroscopy (FT-IR), X-ray powder diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), high resolution transmission electron microscopy (HR-TEM), X-ray photoelectron spectroscopy (XPS) and N2 adsorption-desorption isotherm measurement. The modified NiO/6%PANI/GCE had higher catalytic activity toward the oxidation of glucose than NiO/GCE, PANI/GCE, NiO/2%PANI/GCE and NiO/4%PANI/GCE. This is due to the larger surface area of NiO/6%PANI nanocomposites provide a ploform for faster electron transfer to the detection of glucose. The constructed glucose biosensor have been exhibited a high sensitivity of 606.13 µA mM−1 cm−2, lowest detection limit of 0.19 µM, high selectivity, stability, simplicity and low cost for the quick detection of glucose in real sample as well.

Synthesis and characterization of a novel non-enzymatic glucose biosensor based on polyaniline/zinc oxide/multi-walled carbon nanotube ternary nanocomposite

Novel polyaniline/zinc oxide/multi-walled carbon nanotube (PANI/ZnO/MWCNT) ternary nanocomposite was fabricated as a non-enzymatic glucose biosensor. Thermal chemical vapor deposition (CVD) process was employed to synthesize vertically aligned MWCNTs on stainless steel substrates coated by Co catalyst nanoparticles. In order to fabricate sensitive and reliable MWCNT-based biosensors, nanotubes density and alignment were adjusted by varying the CVD reaction time and cobalt sulfate concentration. The fabricated nanotubes were modified by ZnO particles through the potentiostatic electrodeposition technique. Optimal electrodeposition potential, electrodeposition time, and electrolyte concentration values were determined. The optimized ZnO/MWCNT nanocomposite was reinforced by polyaniline (PANI) nanofibers through the potential cycling technique, and the morphology, elemental composition, and phase structure of the fabricated nanocomposites were characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD), respectively. The sensing mechanism of the PANI/ZnO/MWCNT electrode for the electrochemical detection of glucose was investigated, and the limit of detection and sensitivity values of the designed sensor were determined. The fast response time of the ternary nanocomposite-based sensor as well as its satisfactory stability and reproducibility, makes it a promising candidate for non-enzymatic detection of glucose in biomedical, environmental, and industrial applications.

Nonenzymatic electrochemical glucose biosensor constructed by NiCo2O4@Ppy nanowires on nickel foam substrate

A rational design of multi-component composite used on glucose sensing is important for prevention and treatment of diabetes. In this report, NiCo2O4@polypyrrole nanowires (NiCo2O4@Ppy NWs) were fabricated on a nickel foam (NF) substrate via a well-designed sequential method. Benefitting from a synergy of the 3D-NF, the core of NiCo2O4 nanowires and the conductive coating of Ppy, the hybrid NF/NiCo2O4@Ppy presented a high capability for nonenzymatic electrochemical glucose sensing. The sensitivity of a sensor fabricated with the hybrid could reach as high as 3059 μA mM−1 cm−2, the detection limit could be as low as 0.22 μM (S/N = 3), and the linear range was 0.001–20 mM. In addition, it showed a good reproducibility (R.S.D. = 1.7%) and a high selectivity. The sensing electrode was also feasible in the analysis of real serum samples.

Bifunctional and highly sensitive electrochemical non-enzymatic glucose and hydrogen peroxide biosensor based on NiCo2O4 nanoflowers decorated 3D nitrogen doped holey graphene hydrogel

In this work, a simple strategy for fabricating a 3D nitrogen doped holey graphene hydrogel decorated with NiCo2O4 nanoflowers (NHGH/NiCo2O4) via a one-pot hydrothermal method with subsequent calcination is reported for the first time. The novel NHGH/NiCo2O4 nanocomposites featured high electrical conductivity, large and accessible surface areas, abundant active sites, and excellent electrocatalytic performance. Considering the excellent catalytic activity of NiCo2O4, a sensitive and bifunctional electrochemical non-enzymatic biosensor was established for the determination of glucose and hydrogen peroxide (H2O2). The obtained biosensor exhibited wide linear ranges (glucose: 0.005–10.95 mM; H2O2: 1–510 μM) and a low detection limits (glucose: 0.39 μM; H2O2: 0.136 μM) in alkaline solution (S/N = 3). Excellent electrocatalytic activity of this sensor was ascribed to the synergistic effects of the hybrid structure between the NiCo2O4 nanoflowers and NHGH. Furthermore, the sensitive biosensor also exhibited high selectivity and could be applied to determine glucose in real blood samples. Taken together, the results reveal that the proposed hybrid nanocomposite could be a promising electrochemical biosensor.

Direct growth of 3D porous (Ni-Co)3S4 nanosheets arrays on rGO-PEDOT hybrid film for high performance non-enzymatic glucose sensing

A binder-free, rapid and low-cost electrodeposition technology for growing 3D porous (Ni-Co)3S4 nanosheets arrays on glassy carbon electrode (GCE) functionalized by reduced graphene oxide-poly (3,4-ethylenedioxythiophene) (rGO-PEDOT) hybrid film is successfully developed to construct a sensor for non-enzymatic glucose sensing. The main experimental variables affected on the electrochemical performance are optimized. Benefiting from the synergistic effect of the new active material system, the unique morphology and the strong combination among (Ni-Co)3S4, rGO-PEDOT and bare electrode, the sensor constructed under the optimal conditions manifests wide detection range (1–5000 μM), highly sensitivity (938.4 μA mM−1 cm−2), rapid response (<1.5 s) and low detection limit (0.503 μM). Additionally, the sensor exhibits outstanding selectivity, stability and reproducibility. Significantly, the detection results of the sensor for glucose in human blood serum are well consistent with that in hospital. This research work opens an attractive strategy to construct nanocomposites, and provide a new insight into the development of the non-enzymatic glucose biosensor with high performance.

Towards a dual in-line electrochemical biosensor for the determination of glucose and hydrogen peroxide

Herein, we report the development of a sensitive and selective dual mode electrochemical platform for the detection of glucose and H2O2. The platform is based on tungsten and gold microwire electrodes decorated with gold nanoparticles (AuNPs) and colloidal platinum (colloidal-Pt), respectively. The nanostructured AuNPs electrode was used as a support matrix for the immobilization of horseradish peroxidase (HRP) and the colloidal-Pt served as the non-enzymatic glucose biosensor in the construction of a dual in-line electrochemical biosensor that provides a microenvironment for HRP and a pathway for analyte diffusion via the high surface area. The dual-mode approach allows for the simultaneous detection of glucose and H2O2. The glucose biosensor exhibited a dynamic linear range of 0.5 mM to 8 mM glucose. Linearity for H2O2 was up to 70 μM. Operational stability resulted in 75% of the initial biosensor response after 27 days. The dual in-line biosensor showed good sensitivity of 0.403 mA mM−1 cm−2 for glucose and 0.193 mA mM−1 cm−2 for H2O2 in addition to good anti-interference ability. Thus, the low-cost and simple dual in-line biosensor can be used for the real-time detection of glucose and H2O2 in the clinical, biological and environmental fields.

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.

Development of an impedimetric non enzymatic sensor based on ZnO and Cu doped ZnO nanoparticles for the detection of glucose

In this research, pure and copper-doped Zinc oxide nanoparticles (Cu-ZO) have been prepared by sol gel method. Lots of tests have been carried out for the prepared samples such as crystallinity analysis, microstructures observation and electrochemical property investigations. The electrochemical behavior of the electrodes were evaluated by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). These analyses show that the ZnO and Cu-ZO samples are promising for the development of cost effective non-enzymatic electrochemical glucose biosensors with good features. The prepared Cu-ZO samples sensor represent higher sensitivity and superior electro catalytic activity as compared to that observed for the undoped ZnO nanoparticles. It exhibit a large linear detection range from 10−9 M to 10−5 M and low detection limit of 10−9 M. It is believed that the copper doping revealed a significant effect on the electrochemical properties because it provide more electro catalytic actives sites and more electron transfer for glucose oxidation. Furthermore, measurements in the presence of interfering species haven't affected the response of the analyte of interest which prove the good selectivity of the Cu-ZO. Finally, the electrode was successfully applied to the assess the glucose level in human serum samples.

Cobalt sulfides/carbon nanohybrids: a novel biocatalyst for nonenzymatic glucose biofuel cells and biosensors.

Exploring high-performance electrocatalysts is of great importance in developing nonenzymatic biofuel cells. Hybrid nanostructures with transition metal compounds and carbon nanomaterials exhibit excellent electrocatalytic activity and have emerged as promising low-cost alternatives for various electrochemical reactions. Herein, we report cobalt sulfide/carbon nanohybrids via a facile synthesis, which have excellent electrocatalytic activity for glucose oxidation and oxygen reduction reaction. The nonenzymatic glucose biofuel cells equipped with cobalt sulfide/carbon nanohybrids deliver a high open circuit voltage of 0.72 V with a maximum open power density of 88 μW cm−2, indicating that cobalt sulfide/carbon nanohybrids are high performance biocatalysts for bioenergy conversion.

Synergic effect of plasmonic gold nanoparticles and graphene oxide on the performance of glucose sensing

A highly sensitive Au–GO hybrid nanostructure based non-enzymatic glucose biosensor is fabricated and exhibits superior sensitivity of 84.53 μA mM−1 cm−2. The biosensor also has applications for the detection of glucose in human blood serum, food samples and drinks.

A Biosensor Electrode with Self-Assembled Monolayer of Gold Nanoparticle on a Micro Hemisphere Array

In this study, we first proposed a low-cost and highly reproducible method for the mass production of a novel biosensor electrode with self-assembled monolayer of gold nanoparticle on a micro hemisphere array. An ordered array of micro hemispherical features was formed on a 6-inch reclaimed silicon wafer using photolithography. Then, a thin gold layer was sputtered onto the hemispheres. The wafer was then immersed into a 5 mM ethanol solution of 1,6-hexanedithiol (1,6-HDT) to enable the attachment of one thio-end of 1,6-HDT to the thin gold layer. Finally, a colloidal gold (∼13.5 nm) solution was dripped onto the wafer and baked on a hot plate in such a way that the monolayer of gold nanoparticles could self-assemble on the 1,6-HDT surface. The features of the fabricated biosensor electrodes were then applied for non-enzymatic glucose detections. Chronoamperometry (CA) detection of glucose demonstrated that the proposed non-enzymatic glucose biosensor can operate in a linear range from 1.39 to 13.89 mM with a sensitivity of 336.1 μA•mM−1•cm−2 and a detection limit of 5.2 μM. The accuracy of the developed glucose biosensor reaches ±1.29%, which is significantly better than the FDA and ISO 15197 standard of ±15%. The relatively high repeatability of the proposed glucose biosensor can be attributed to the uniform semiconductor fabrication process and the extremely ordered self-assembled monolayer of gold nanoparticles. The proposed biosensor can be easily produced on a large scale, the cost of fabrication is low, repeatability is high, and is easy to preserve on a long-term basis.

Template synthesis of the Cu2O nanoparticle-doped hollow carbon nanofibres and their application as non-enzymatic glucose biosensors.

The cuprous oxide nanoparticle (Cu2O NP)-doped hollow carbon nanofibres (Cu2O/HCFs) were directly synthesized by the anodic aluminium oxide (AAO) template. The doped Cu2O NPs were formed by in situ deposition by direct reduction reaction of precursor carbonization in thermal decomposition and could act as functionalized nanoparticles. The synthesized Cu2O/HCFs were characterized in detail by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy and inductively coupled plasma mass spectrometry (ICP-MS). The results reveal that Cu2O/HCFs have a tubular structure with an average diameter of approximately 60 nm. The shape of the Cu2O/HCFs is straight and Cu2O NPs are uniformly distributed and highly dispersed in HCFs. Cu2O/HCFs have good dispersibility. The electrochemical activity of Cu2O/HCFs was investigated by cyclic voltammetry (CV), the glucose sensors display high electrochemical activity towards the oxidation of glucose. Cu2O/HCFs can effectively accelerate the transmission of electrons on the electrode surface. Cu2O/HCFs are applied in the detection of glucose with a detection limit of 0.48 µM, a linear detection range from 7.99 to 33.33 µM and with a high sensitivity of 1218.3 µA cm−2 mM−1. Moreover, the experimental results demonstrate that Cu2O/HCFs have good stability, reproducibility and selectivity. Our results suggest that Cu2O/HCFs could be a promising candidate for the construction of non-enzymatic sensor.

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.

Synthesis of the crystalline porous copper oxide architectures derived from metal-organic framework for electrocatalytic oxidation and sensitive detection of glucose

The porous CuO architectures have been successfully synthesize by the effective transformation of a Cu-BTC metal-organic frameworks (MOFs) through a facile heating treatment. The as-synthesized porous CuO architectures exhibit high electrocatalytic activity toward the glucose oxidation. When evaluated as a nonenzymatic glucose biosensor, the porous CuO architectures manifest fast response within 1.3s, wide linear range from 0.5μM to 2.8mM, low detection limit of 0.1μM (signal-to-noise ratio of 3), high sensitivity up to 934.2μAmM−1cm−2 as well as favorable reproducibility.

Nanoporous gold induced vertically standing 2D NiCo bimetal-organic framework nanosheets for non-enzymatic glucose biosensing

Designing new efficient electrocatalysts is of considerable importance for the non-enzymatic electrochemical glucose biosensors development. Herein, novel vertical two-dimensional (2D) NiCo bimetal-organic framework (NiCo-MOF) parallelogrammic nanosheets array is successfully prepared on the surface of nanoporous gold by a bottom-up strategy. Nanopores are essential for directing the vertical growth of 2D-MOF nanosheets and preventing them from stacking to form NiCo-MOF arrays. This vertical allignment feature of nanosheets exposes more accessible active sites and facilates fast mass and charge transport for electrochemical reactions. The strong electron interaction among N, Co, and Ni enhances the electrochemical catalytic oxidation of glucose. 2D NiCo-MOF nanosheets array electrode exhibits high performance for glucose detection with a broad linear ranges of 1 μM to 8 mM, a rapid response time of less than 1 s, a high sensitivity of 0.6844 mA·mM−1 cm−2, and a low detection limit of 0.29 μM. This novel vertical aligned NiCo-MOF nanosheets array is also one kind of promising candidates for multifunctional applications in other fields of energy or catalysis.

One step synthesis of hierarchical Cu nanoparticles-Co(OH)2 nanoflakes/Nifoam electrode for ultrasensitive detection of glucose

Co(OH)2 nanoflakes integrating with Cu nanoparticles were deposited on nickel foam (CuNps-Co(OH)2Nfs/Nif) by a green and facile one-step deposition method and used for non-enzymatic glucose sensors. The CuNps-Co(OH)2Nfs/Nif composite was characterized by scanning electron microscopy, X-ray photoelectron spectroscopy and high resolution transmission electron microscopy. Electrochemical oxidation of glucose on the CuNps-Co(OH)2Nfs/Nif composite was investigated by chronoamperometry and cyclic voltammetry. The prepared CuNps-Co(OH)2Nfs/Nif electrode shows not only an extremely high sensitivity of 42.7 mA mM−1 cm−2 in the concentration range from 1 to 250 μM for glucose detection but also an obvious current response to glucose at a level of 1 μM with a low detection limit of 73 nM (S/N = 3). Moreover, the glucose sensor based on CuNps-Co(OH)2Nfs/Nif also exhibits high recovery ratio toward real sample analysis. This work indicates that the fast electron transfer, large surface area, and highly effective active sites based on the hierarchical structure of ultra-thin and open-interlaced Co(OH)2Nfs interspersed by CuNps contribute to the excellent performance of CuNps-Co(OH)2Nfs/Nif electrodes. The proposed one-step preparation of hierarchical nanostructure of CuNps and Co(OH)2Nfs provides a promising and efficient strategy in the development of outstanding non-enzymatic glucose biosensors.

Ultrasensitive and highly flexible nonenzymatic glucose biosensor based on laser-scribed carbon paper substrate

Owing to the high specific surface area and easy accessability to targeting biomolecules, emerging non-noble-metal networks are developed as an ultra-active catalyst for molecular detection. In this work, a facile flexible enzyme-free glucose sensor with superior sensing performance has been successfully constructed by integrating laser-scribed carbon paper (LSCP) with copper network (CN). Remarkably, operation parameters are modeled and optimized by Central Composite Design (CCD) to obtain an optimal conductivity of 4.783 × 107 S·m−1 for CN. Due to the great electronic/ionic pathway between LSCP of ample active sites and CN of excellent conductivity, the disposable biosensor exhibits fast electron transfer kinetics. For glucose detection, LSCP/CN exhibits an excellent sensitivity of 3626.6 μA mM−1 cm−2, a wide linear range from 1 μM to 7.96 mM, an ultra-low detection limit of 30 nM (S/N = 3) as well as favorable reusability. Satisfactory anti-interference capacity to electro-active oxides and selectivity against carbohydrates studied for concentrations up to normal physiologic levels and higher concentrations are systematically investigated. The applications of glucose determination in human serum and perspiration samples are also successful, with recoveries of 100.8% (± 2.28%) and 92.1% (±3.61%), respectively. Experimentally, the current response of the LSCP/CN biosensor is resilient to mechanical deformation with less than 8% decay even after 1000 cycles of 1 mm repeated bending and 180° cyclical folding tests. As such, LSCP/CN can be applicable for flexible, attachable and potentially wearable biosensors to attain real-time physiological monitoring.

Non-enzymatic glucose biosensor based on reduction graphene oxide-persimmon tannin-Pt-Pd nanocomposite

Herein, a novel non-enzymatic glucose sensor was fabricated based on the reduction graphene oxide-persimmon tannin-platinum-palladium alloy (RGO-PT-Pt-Pd) nanocomposite. The RGO-PT-Pt-Pd nanocomposite was prepared through a facile approach with PT as film material and ascorbic acid as reducing agent and characterized by ultraviolet visible spectroscopy (UV-vis), Fourier transform infrared spectroscopy (FT-IR), Scanning electron microscopy (SEM), X-Ray diffraction (XRD) and so on. Then, the synthesized RGO-PT-Pt-Pd nanocomposite was employed as an electrode material for non-enzymatic glucose sensing using gold electrode (GE). The RGO-PT-Pt-Pd/GE sensor showed outstanding catalytic activity toward glucose oxidation. The prepared amperometric sensor exhibited a wide linear range of 0.01-0.40 mol/L with a limit of detection (1.43 μmol/L) as well as high stability and fast responsetime (<3s). Therefore, the glucose biosensor has the potential to be used for clinical blood glucose detection.