Fabrication Of Non-enzymatic Glucose Sensor Research Articles

Electrodeposited Fabrication of CeO2 Branched-like Nanostructure Used for Nonenzymatic Glucose Biosensor

The fabrication of nonenzymatic glucose sensors is essential because of the enhancement in the selectivity and accuracy of these sensors. In this work, we used the electrodeposition approach to prepare a CeO2-based electrode for nonenzymatic glucose detection. A CeO2 branched-like nanostructure was successfully fabricated by electrodeposition on the surface of a Au substrate electrode at room temperature. The effects of cyclic voltammetry, CH3COOH content, and scan cycle number on the formation of the CeO2 branched-like nanostructure were investigated. The fabricated electrodes were characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). The results showed that a CeO2 branched-like nanostructure could be obtained with a CH3COOH content of 1.0 mL and a scan cycle number of 100 in a solution containing 0.015 M Ce(NO3)3, 0.01 M KCl, and 0.02 M CH3COONH4 and with a scan rate of 400 mV/s. The electrochemical characteristics of the sensor were examined by chronoamperometry and cyclic voltammetry. The results showed that the sensitivity of the sensor was 37.72 μA/mM·cm2 and the limit of detection (LOD) of the sensor was 0.093 mM. The findings in this work prove that it is feasible to fabricate CeO2-based sensors for nonenzymatic glucose detection.

Cu-Ag bimetallic nanostructures with high glucose sensing performance fabricated by a scalable and reproducible method

A scalable and repeatable synthetization method is introduced to fabricate Cu-Ag bimetallic nanostructures as a stable, robust, fast-response and enzyme-free glucose sensor. Cu nanocolumns were constructed on the FTO substrate using the glancing angle deposition (GLAD). Then a thin layer of Ag is deposited on the Cu nanocolumns through a galvanic replacement reaction. The Cu-Ag nanostructures with different morphologies were developed by tuning the concentration and the reaction time of the galvanic replacement process. Various electrochemical characterizations, including cyclic voltammetry and electrochemical impedance spectroscopy (EIS), were performed to determine the superior electrocatalytic activity of the electrodes. The results reveal that the superior electrocatalytic performance toward glucose oxidation was achieved with Cu-Ag fabricated under the AgNO3 concentration of 5 mM and with a reaction time of 30 s. The sensor exhibits a fast response of ∼2 s with an excellent sensitivity of 3802 and 712 μAcm−2 mM−1 in two wide linear ranges of 0.01–3 mM and 3–8 mM and an optimum potential of 0.65 V. The proposed Cu-Ag sensor showed considerable enhancement of electrocatalytic activity compared to Cu or Ag monometallic structures due to the synergistic effect. In addition, the current bimetallic sensor regarding its outstanding precision and its reproducibility provides a promising method for large scale fabrication of non-enzymatic glucose sensors.

Commercial Screen-Printed Electrode Decorated with Carbonaceous Binary Sulfides for Direct Glucose Detection in Human Fluid Samples

We hereby demonstrate a highly controllable, green, and rapid synthesis strategy for the production of binary metal sulfides on carbon nano-horns (CNHs) for the fabrication of non-enzymatic glucose sensor using commercial graphite screen-printed electrodes (GSPEs). CNHs were synthesized using the submerged arc discharge method as described elsewhere. In the next step, one droplet (50 µL) of the well-dispersed CNHs was carefully cast on the surface of the GCE (and GSPE). In the final step of preparing the modified electrodes, CNH/GCEs were covered by a thin layer of nickel cobalt sulfide by a simple electrochemical deposition procedure.Following the structural examination of the prepared electrocatalyst were examined. In this regard, several microscopic methods like FE-SEM or TEM were used to know more regard the morphology of the material. The FE-SEM images confirmed the successful formation of sponge like nanosheets of NiCo-S on carbonaceous material. Since CNHs are prepared from graphene sheets with open ends in horn-like shapes, they can be considered as being formed from the origami-like or crushing contortion of a single graphene sheet. According to the FE-SEM images, the agglomeration of CNHs establishes discrete nano-sphere structures with diameters in the range of 50 to 150 nm. The TEM images also confirm this nano-sphere strictures.Following detailed structural characterization, the electrocatalytic activity of the fabricated NiCo-S/CNH electrodes toward electro-oxidation of glucose is examined in detail. The cyclic voltammetry was also used for glucose electro-oxidation mechanism investigation. In addition, parameter optimization was also done by utilizing cyclic voltammetry technique. These include medium pH, deposition cycles, and metals mole ration. Moreover, the effect of the presence and absence of CNH on the electrochemical performance of glucose oxidation were also examined. It shows that in the presence of CNH the peak current density for glucose oxidation is higher that is perfect for analytical purposes and increase the analytical sensitivity. The structural properties and electrochemical response of the fabricated electrodes were also compared to their corresponding mono-metallic counterparts.The amperometric method was utilized as one of the most prevalent and momentous techniques for the quantitative determination of glucose. The applied potential in amperometric tests was optimized to be +0.5 V (vs. Ag/AgCl). The proposed electrodes were operated within two distinct linear dynamic ranges of 0.001- 0.330 mM and 0.330 - 4.53 mM of standard glucose with sensitivities of 1842 µA.mM-1.cm-2, and 854 µA.mM-1.cm-2, respectively. On the other hand, an analytical sensitivity of 467 µA.mM-1.cm-2, within the linear dynamic range of 0.5 - 6 mM was obtained for the static chronoamperometric measurements for modified commercial screen-printed electrode (GSPE). The proposed sensor showed outstanding selectivity against iso-structures and co-existing interferences, long-term durability, rapid response (1.7 s), excellent poisoning resistance against chloride ions, good repeatability, and reproducibility. The tested interferences were 0.1 mM solutions of fructose, galactose, sucrose, lactose, ascorbic acid, uric acid, dopamine hydrochloride, and NaCl. In order to demonstrate the capability of the fabricated electrodes and to evaluate their potential for glucose measurements in real physiological specimens, the glucose level was successfully measured in human blood serum, urine, and saliva samples, without any sample pre-treatment. All in all, the encouraging results make NiCo-S/CNH electrodes immensely promising for clinical and physiological glucose-level measurements.Figure 1. (a) FE-SEM image of CNH. (b) FE-SEM image of NiCo-S/CNH. (c) TEM image of CNHs. (d) Cyclic voltammogarm of NiCo-S/CNH in the absence and presence of various concentration of glucose. (e) The amperometric responses of the NiCo-S/CNH/GCEs after addition of 1 mM glucose followed by successive injection of 0.1 mM fructose, galactose, sucrose, lactose, AA, UA, DA, and NaCl. (f) Chrono amperograms of the NiCo-S/CNH/GSPEs in the presence of the different glucose concentration ranging from 0.5 ~ 10.0 mM under applying +0.5 V. Amperogram of the NiCo-S/GCEs current response obtained from the addition of (g) 50 µL human blood serum, (h) 200 µL urine, and (i) 100 µL saliva followed by injection of 400 µM standard glucose solutions under the optimum potential of +0.5 V, the amperograms of five successive glucose addition. Figure 1

Green Fabrication of Nonenzymatic Glucose Sensor Using Multi-Walled Carbon Nanotubes Decorated with Copper (II) Oxide Nanoparticles for Tear Fluid Analysis.

In this report, a green, simple, inexpensive, and effective nonenzymatic electrochemical glucose sensor was fabricated using multi-walled carbon nanotubes (MWCNT) decorated with copper (II) oxide nanoparticles (CuO NPs). Basil seed mucilage (BSM) was served as reducing, capping, and stabilizing agents in the synthesis of CuO NPs.The prepared MWCNT/CuO nanocomposite was characterized using Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), and electrochemical methods. The FTIR results indicated that the nanocomposite surface was covered by BSM. The FESEM results show that the CuO NPs with an average particle size lower than 10nm have been well distributed on the walls of the MWCNT. The electrochemical behavior of the nanocomposite was explored by studying the electrocatalytic behavior of the screen-printed carbon electrode (SPCE) modified by the nanocomposite (SPCE-MWCNT/CuO) toward the glucose oxidation. In the optimum conditions, the electrode indicated a wide linear response from 5.0 to 620.0μM with regression coefficients of 0.992, the sensitivity of 1050 μA mM-1cm-2, a limit of detection (LOD) of 1.7μM, and a reproducibility with relative standard deviation (RSD) variations from 3.5 to 11% for three measurements at each point. The obtained results also showed good selectivity to glucose against interfering species such as lactate (LA), L-ascorbic acid (AA), and urea (U) due to the use of the negatively charged BSM in the form of a coating on the nanocomposite surface. The applicability of the sensor was successfully verified by the determination of glucose concentration in artificial tears with a certain amount of glucose.

Facile synthesis of copper oxide microflowers for nonenzymatic glucose sensor applications

In this manuscript, an attempt has been made to synthesize well-crystallized flower-shaped copper oxide hierarchical structures by simple solution process for fabrication of nonenzymatic glucose sensor under alkaline conditions. Scanning and Transmission electron micrographs clearly illustrate that CuO structures are flower-like shape while X-ray diffraction (XRD) and Fourier Transform Infrared (FT-IR) analyses indicate the formation of pure CuO monoclinic phase. Modified electrode with CuO microflowers shows a wide linear response towards glucose in the concentration range of 10–120 µM with a detection limit of 6.48 µM (S/N = 3). Such results have revealed that CuO microflowers show excellent electrocatalytic activity and efficient electron transport property; hence it may be a promising candidate for the nonenzymatic glucose sensor applications.

Nanoparticles-assembled NiO nanosheets templated by graphene oxide film for highly sensitive non-enzymatic glucose sensing

Nanoparticles-assembled NiO nanosheets have been successfully prepared using graphene oxide (GO) film as template, where the Ni2+ ion was firstly adsorbed in GO film, followed by calcination in N2 to form NiO-based materials and calcination in air to remove carbon-based template. The morphology, structure, and electrochemical activities of these NiO nanosheets were characterized by X-ray diffraction (XRD), transmission electron microscope (TEM) and electrochemical techniques, respectively. It is found that the NiO nanosheets thus obtained could electrochemically catalyze glucose oxidation in 0.1M NaOH, leading to fabrication of non-enzymatic glucose sensor. The glucose sensor based on NiO nanosheets exhibits detection limit of 0.18μM, and linear range from 1μM to 0.4mM with the sensitivity of 1138μAmM−2cm−2. Furthermore, such glucose sensor also shows excellent selectivity for detection of glucose, compared to the commonly interfering species, such as ascorbic acid, dopamine, and uric acid.

Fabrication of non-enzymatic glucose sensor based on nanocomposite of MWCNTs-COOH-Poly(2-aminothiophenol)-Au NPs

A non-enzymatic electrochemical biosensor was developed as detector of glucose based on an electrode modified with MWCNTs-COOH-Poly(2-aminothiophenol)- Au nanoparticles (MWCNTs-COOH-P2AT-Au NPs). The MWCNTs-COOH-P2AT-Au nanocomposite was synthesized using an in situ reduction process. The prepared nanocomposite was characterized by transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and Brunauer-Emmett-Teller (BET).The MWCNTs-COOH-P2AT-Au NPs shows a good electrochemical activity for electrocatalytic oxidation of glucose in alkaline medium. The proposed biosensor exhibits a broad linear calibration range (0.1–30mM) and a low detection limit of 3.7μM for quantification of glucose. The experiment results also demonstrated that the sensor shows good reproducibility, sensitivity, selectivity and long-term stability, as well as high selectivity. The nanocomposite modified electrode is relatively insensitive to electroactive interfering species which are commonly found in blood samples. The results demonstrated that prepared biosensor have good potential for use as ideal inexpensive amperometric glucose biosensor applicable for complex matrices.

Nonenzymatic glucose sensor based on ITO electrode modified with gold nanoparticles by ion implantation

A novel nonenzymatic glucose sensor, based on gold nanoparticle-modified indium tin oxide electrode (Au/ITO) with ion implantation technique, is presented in this article. Ion implantation method is simple, low-cost and environmental friendly without using any of other chemicals. Through this method, the ITO substrate can be modified by gold nanoparticles (AuNPs) directly. The fabricated electrode was characterized by atomic force microscopy (AFM), X-ray photoelectron spectroscopy analysis (XPS) and cyclic voltammetry (CV). Electrochemical oxidation of glucose with Au/ITO electrode was examined by CV in alkaline aqueous solution. The modified electrode exhibits good electrochemical behavior towards glucose, providing a wide linear range of 1∼170μM and 0.2∼15mM and a low detection limit with 0.4μM. Moreover, this glucose sensor displays acceptable reproducibility and long-term stability. These results indicate that Au/ITO electrode makes it promising for the fabrication of nonenzymatic glucose sensors.

Non-Enzymatic Glucose Sensor Based on Well-Crystallized ZnO Nanoparticles

In this paper, well-crystallized ZnO nanoparticles were rapidly synthesized by facile simple solution process at low temperature and used as an efficient electron mediator for the fabrication of non-enzymatic glucose sensor. The synthesized nanoparticles were characterized in terms of their morphological, structural and compositional properties. The detailed morphological characterizations confirmed the large-scale synthesis of well-crystalline wurtzite hexagonal phase ZnO nanoparticles with the typical sizes of 35 ± 5 nm. The as-synthesized nanoparticles were effectively used as an electrode material for the fabrication of efficient, highly sensitive and reproducible non-enzymatic glucose sensor. The fabricated glucose sensor shows a high and reproducible sensitivity of 38.133 � A/cm 2 mM with a response time less than 5 s. A linear dynamic range from 1∼10 mM and correlation coefficient of R = 0.9988 were observed for the fabricated sensor. The presented work demonstrated that the synthesized ZnO nanomaterials could act as effective electron mediators for the fabrication of efficient non-enzymatic glucose sensors.

Fabrication of Nonenzymatic Glucose Sensors Based on Multiwalled Carbon Nanotubes with Bimetallic Pt-M (M = Ru and Sn) Catalysts by Radiolytic Deposition

Nonenzymatic glucose sensors employing multiwalled carbon nanotubes (MWNTs) with highly dispersed Pt-M (M = Ru and Sn) nanoparticles (Pt-M@PVP-MWNTs) were fabricated by radiolytic deposition. The Pt-M nanoparticles on the MWNTs were characterized by transmittance electron microscopy, elemental analysis, and X-ray diffraction. They were found to be well dispersed and to exhibit alloy properties on the MWNT support. Electrochemical testing showed that these nonenzymatic sensors had larger currents (mA) than that of a bare glassy carbon (GC) electrode and one modified with MWNTs. The sensitivity (A mM−1), linear range (mM), and detection limit (mM) (S/N = 3) of the glucose sensor with the Pt-Ru catalyst in NaOH electrolyte were determined as 18.0, 1.0–2.5, 0.7, respectively. The corresponding data of the sensor with Pt-Sn catalyst were 889.0, 1.00–3.00, and 0.3, respectively. In addition, these non-enzymatic sensors can effectively avoid interference arising from the oxidation of the common interfering species ascorbic acid and uric acid in NaOH electrolyte. The experimental results show that such sensors can be applied in the detection of glucose in commercial red wine samples.

Facile synthesis of porous tubular palladium nanostructures and their application in a nonenzymatic glucose sensor

Porous tubular palladium nanostructures were synthesized by electrodeposition of palladium into a CdS modified alumina template and subsequent removal of CdS; the nanostructures provided a promising platform for the fabrication of nonenzymatic glucose sensors.

Gold nanowire array electrode for non-enzymatic voltammetric and amperometric glucose detection

The non-enzymatic voltammetric and amperometric detection of glucose using a gold nanowire array electrode is described. The voltammetric detection of glucose was performed by cyclic and differential-pulse voltammetry. The detection of glucose by partial and direct oxidation of glucose during the anodic and cathodic potential sweeps was shown in cyclic voltammetry. An unusual decrease in overpotential for partial oxidation of glucose on a Au NW array electrode was observed. A linear differential-pulse voltammetric response for partial oxidation of glucose was observed up to a glucose concentration of at least 20 mM with a sensitivity of 41.9 μA mM −1 cm −2 and detection limit below 30 μM (signal-to-noise ratio of 3) for glucose oxidation at low potentials, where the influence of possible intermediates can be avoided. The amperometric response was also linear up to a glucose concentration of 10 mM with a sensitivity of 309.0 μA mM −1 cm −2. The wide dynamic range and high sensitivity, selectivity and stability, as well as good biocompatibility of the Au NW electrode make it promising for the fabrication of non-enzymatic glucose sensors.

Nonenzymatic Glucose Detection with Good Selectivity Against Ascorbic Acid on a Highly Porous Gold Electrode Subjected to Amalgamation Treatment

AbstractA nonenzymatic glucose sensor with good selectivity for the ascorbic acid oxidation is presented. After the gold polycrystalline electrode was subjected to amalgamation treatment, two advantageous effects were observed. One is the enhancement of the surface roughness and the other is an increase in the catalytic current in the glucose oxidation. Besides the known first effect, the latter provided another advantageous effect in a fabrication of nonenzymatic glucose sensor. Using a gold electrode subjected to amalgamation treatment for 60 s, two calibration curves for glucose oxidation at two different potentials of −0.1 V and 0.25 V were obtained and compared. At the potential of −0.1 V, at which no ascorbic acid was oxidized and no interference effect was observed, a current sensitivity of 16 μA cm−2 mM−1 from zero to 10 mM glucose concentration range was obtained. At the other potential of 0.25 V, at which ascorbic acid was easily oxidized, a satisfactory calibration curve with negligible ascorbic acid interference was also obtained together with a more enhanced current sensitivity of 32 μA cm−2 mM−1.

Study of the nonenzymatic glucose sensor based on highly dispersed Pt nanoparticles supported on carbon nanotubes

An amperometric biosensor for sensitive and selective detection of glucose has been constructed by using highly dispersed Pt nanoparticles supported on carbon nanotubes (Pt-MWCNTs) as sensing interface. The Pt-MWCNTs were synthesized by using the two-step pyrolysis method. This composite shows good electrocatalytic activity towards the oxidation of glucose in alkaline and thus can be used to selectively detect glucose. We found that detection potential and Nafion amount covered on the Pt-MWCNTs modified glassy carbon electrode had considerable influence on the selectivity for amperometric detection of glucose. Under optimal detection conditions (detection potential of 0.0 V versus SCE and 10 μL 1.5% Nafion), selective detection of glucose in the glucose concentration range of 1.0–26.5 mM (correlation coefficient, >0.999) can be performed. The results demonstrate that the Pt-MWCNTs composite is promising for the fabrication of nonenzymatic glucose sensors.