Enzymeless Glucose Sensor Research Articles

Shell@Core Coaxial NiO@Ni Nanowire Arrays as High Performance Enzymeless Glucose Sensor

Vertically aligned nanowire array based sensor platform that can monitor electro active species without the requirement of enzyme have received much attention lately. In particular, vertically aligned Ni nanowire arrays (NiNAE) have been found to have excellent catalytic activity toward carbohydrates. However, nickel oxidizes or corrodes in air, and this presents a question about its usefulness as a reliable and stable sensing materials. To address this problem, the authors have developed a vertically aligned co-axial nickel oxide-nickel nanowire array electrode (NiO@NiNAE) platform which can detect glucose without the presence of enzyme. The fabrication procedure is simple and catalytic activity toward glucose has been found to be excellent, this is attributed to the presence of stable NiO around the Ni nanowire. Details of morphological and electrochemical characterization of the sensor platform have been studied to evaluate the sensor performance. The sensitivity of NiNAE and NiO@NiNAE has been found to be 80.0 and 170.4 mC mM−1 cm−2, respectively. Under optimal detection conditions, the as prepared sensors exhibited linear behavior for glucose detection in the concentration up to 7 mM for both NiNAE and NiO@NiNAE with a limit of detection of 33 and 14 μM, respectively.

Graphene oxide–thionine–Au nanostructure composites: Preparation and applications in non-enzymatic glucose sensing

Herein, we demonstrated a facile strategy for preparing high-loading Au nanoparticles using thionine functionalized graphene oxide as the supporting material. Glassy carbon electrodes modified with the as-obtained nanocomposites showed remarkably electrocatalytic activity towards the oxidation of glucose, leading to an enzymeless glucose sensor with a wide linear range and a lower detection limit of 0.05 μmol/L.

Dendritic Bimetallic Nanostructures Supported on Self-Assembled Titanate Films for Sensor Application

The electrochemical properties of electrodes modified with metal/metal oxides depend not only on the nature of the materials but also on the composition and substrate as well. In this study, dendritic CuNi nanostructured materials with a distinguishable bimetal phase were achieved by electrodeposition in 0.05 M Na2SO4 solution containing 0.05 M CuSO4 and 0.05 M NiCl2 at −1.0 V on the surface of titanate thin films, which were self-assembled from the titanate nanaosheets exfoliated by n-propylamine. The structures, morphologies, and elemental molar ratio of the titanate-supported CuNi were analyzed by XRD, SEM, and ICP-AES, respectively. The electrochemical activities of the CuNi nanostructured electrodes toward glucose oxidation were evaluated, and factors that affect the electrocatalytic activities of the electrodes were examined and optimized. The potential applications of the CuNi nanostructured films for fabrication of enzymeless glucose sensors were also investigated. The assay performances of the sensor evaluated by conventional electrochemical techniques revealed a quick response, good reproducibility, and enhanced sensitivity in glucose determination compared with that of pure Cu or Ni electrodeposited on the self-assembled titanate template.

A Novel Non-Enzymatic Glucose Sensor Based on Nickel (II) Oxide Electrospun Nanofibers

A new enzymeless glucose sensor has been fabricated via electrospinning technology and subsequent calcination. The morphology and structure of the as-prepared nanofibers have been characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray diffraction (XRD). The electrocatalytic oxidation of glucose in alkaline medium at nickel oxide modified glassy carbon electrodes has been investigated. The modified electrodes offer excellent electrocatalytic activity toward the glucose oxidation at low positive potential (0.3 V). Glucose has been determined chronoamperometrically at the surface of NiO nanofibers modified electrode in 0.5 mM NaOH. Under the optimized condition, the calibration curve is linear in the concentration range of 2 x 10(-3) mM - 1 mM, and 1 mM - 9.5 mM. The detection limit (signal-to-noise 3) and response time are 3.394 x 10(-6) M and 2 s, respectively. The NiO electrospun nanofibers is easy to prepare and feasible in economy. The modified electrode is steady and can be used repeatedly, so it is reasonable to expect its broad use in non-enzymatic glucose sensor.

A novel non-enzymatic electrochemical glucose sensor modified with FeOOH nanowire

The recent development in the nanotechnology has paved the way for large number of new materials and devices of desirable properties which have useful functions for electrochemical sensor and biosensor applications. In this paper, a novel enzymeless glucose sensor is developed on the discovery that the FeOOH nanowire in fact possesses an intrinsic enzyme mimetic electrocatalytic activity similar to that found in natural peroxidases. The electrode modified with FeOOH nanowires showed a wide linear range (15 μM–3 mM) and high sensitivity (12.13 μA mM − 1 ) for glucose sensing. Other excellent performances such as highly reproducible response, long-term stability, sound mechanical and chemical stability are also observed, and the interferences of ascorbic acid and dopamine can almost be completely avoided. The good analytical performance, low cost and straightforward preparation method made this novel electrode material promising for the development of effective glucose sensors.

Amperometric Nonenzymatic Determination of Glucose Free of Interference Based on Poly (Sulfosalicylic Acid) Modified Nickel Microelectrode

A novel enzymeless glucose sensor of poly (sulfosalicylic acid) film modified nickel disk-microelectrode based on glucose electrochemical oxidation directly in 0.01 mol dm−3 NaOH has been fabricated. It shows excellent electrocatalytic activities towards glucose oxidation at a low positive potential of 0.49 V (vs. Ag/AgCl). The calibration curve is linear in the glucose concentration range of 6.0 × 10−6 to 1.0 × 10−3 mol dm−3 with a detection limit 9 × 10−7 mol dm−3 (S/N = 3) and sensitivity 3.8 mA μM−1 cm−2. The presented glucose sensor is selective, sensitive, and rapid in response time. It had been used to direct determination of glucose in serum.

Silver Oxide Nanowalls Grown on Cu Substrate as an Enzymeless Glucose Sensor

Ag(2)O nanowalls consisting of densely packed nanoplates based on a Cu substrate were synthesized through a facile one-pot hydrothermal method. A new enzymeless glucose sensor of Cu-Ag(2)O nanowalls was fabricated. The Cu-Ag(2)O nanowalls showed higher catalysis on glucose oxidation than traditional Ag(2)O nanoflowers and Cu-Ag(2)O nanospindles. At an applied potential of 0.4 V, the sensor produced an ultrahigh sensitivity to glucose (GO) of 298.2 microA mM(-1). Linear response was obtained over a concentration range from 0.2 mM to 3.2 mM with a detection limit of 0.01 mM (S/N = 3). Satisfyingly, the Cu-Ag(2)O nanowalls modified electrode was not only successfully employed to eliminate the interferences from uric acid (UA) acid ascorbic (AA) and also fructose (FO) during the catalytic oxidation of glucose. The Cu-Ag(2)O nanowalls modified electrode allows highly sensitive, excellently selective, stable, and fast amperometric sensing of glucose and thus is promising for the future development of nonenzymatic glucose sensors.

Investigations on copper–titanate intercalation materials for amperometric sensor

Copper-based titanate intercalation electrode materials (referred as Cu–TO) were achieved by electrochemical reduction of the intercalated cupric ions that were ion exchanged on the layer structured titanate films by using n-propylamine as an exfoliating agent. The copper-based titanate intercalation electrode materials were characterized by X-ray diffraction (XRD), electrochemical techniques and inductive coupled plasma-atomic emission spectroscopy (ICP-AES). These copper-based titanate materials were exploited to fabricate the enzymeless glucose sensors, and their assay performances to glucose were evaluated by conventional electrochemical techniques. Cyclic voltammetry (CV) and chronoamperometry (I–t) revealed a high sensitivity, fast response, excellent stability, and good reproducibility in the glucose determination at +0.55V. Under optimal conditions, the electrocatalytic response of the sensor was proportional to the glucose concentration in the range of 2.5×10−7M to 8.0×10−3M with a detection limit of 5.0×10−8M (signal-to-noise=3). Moreover, the intercalated copper electrode materials exhibited high stability and improved selectivity for glucose compared with the more apparently accessible copper. This work also provides a simply controlled test-bed for electrochemical functionalization of layered titanate for sensor applications.

Self-assembled microstructure of carbon nanotubes for enzymeless glucose sensor

This work demonstrated the use of self-assembled thin films of multi-walled carbon nanotubes (CNTs) in designing enzymeless glucose sensor. Well-dispersed self-assembled CNT were prepared based on the spontaneous and strong chemisorption of polyoxometalates on CNT surface. Electrostatically self-assembled CNT films interlaced with cationic polyelectrolyte binding layer were constructed and used to confine the growth of copper (Cu) metal particles by the pulsed electrodeposition technique. The morphology of electroplated Cu on the CNT film was confirmed by scanning electron microscopy (SEM), and Cu were deposited as uniformly dispersed individual particles rather than continuous film on the CNT substrate. Sensing and assay performance of the copper deposits on CNT films to glucose were evaluated in detail. Cyclic voltammetry (CV), chronoamperometry ( I– t) and flow injection amperometry (FIA) revealed a high sensitivity, excellent stability, and good reproducibility in the glucose determination. The current response of the sensor reached 602.04 μA mM −1 cm −2 with enough high signal to noise ratios at various glucose concentration levels, which was superior than those of Cu electrodeposition on CNT reported so far. A detection limit of 1.0 × 10 −7 M (signal-to-noise = 3) and a linear range of 5.0 × 10 −7 to 1.8 × 10 −3 M were obtained. Present study provides a low cost and simply controlled test-bed for fundamental study on using self-assembled CNT films for sensor fabrication.

Development of Guidelines for Nanobiosensor Evaluation as Medical Devices

To use nanobiosensors as diagnostic devices, they should be evaluated and approved as medical devices before marketing. This study was performed to establish appropriate evaluation guidelines that provide how to verify the safety and effectiveness of a novel nanobiosensor as a medical device. We prepared an enzymeless glucose sensor with nanoporous platinum electrode to evaluate performance and stability by comparing it with a commercial enzyme-based glucose sensor. Through these evaluation studies, we developed guidelines, and the guidelines consist of five parts: evaluation of analytical performance, clinical performance, safety, stability, and design and quality control systems. Analytical and clinical performance of nanobiosensors should be evaluated by accuracy, sensitivity, reproducibility, cut-off value, and other specific performance characteristics. Also, electric, mechanical, and biological safety should be evaluated. With the performance and safety, validation of storing conditions and shelf life should be established with evaluation and characterization of nano-structured parts for stability evaluation. Then, design and quality control systems should be evaluated in the aspect of quality requirements, material, manufacturing process, and final product. These guidelines will be helpful for facilitating the commercialization of the safe, effective, and novel diagnostic nanobiosensors into market place.

Preparation and Electrocatalytic Performance of Functionalized Copper‐Based Nanoparticles Supported on the Gold Surface

AbstractCopper nanoparticles (CuNPs) encapsulated by polymeric stabilizer of polyvinylpyrrolidone (PVP) (noted as PVP‐CuNPs) were simply prepared and used to construct an enzymeless glucose sensor on a solid substrate. Sensing and assay performance of the CuNPs‐based sensor to glucose were evaluated in detail. Cyclic voltammetry (CV), chronoamperometry (I–t) and flow injection amperometry (FIA) revealed a high sensitivity, excellent stability, and good reproducibility in the glucose determination at +0.45 V, which was 200 mV more negative than those in former reports. A detection limit as low as 1.0×10−8 M (signal‐to‐noise=3) and a linear range of 1.0×10−7 M to 5.0×10−3 M were obtained in this study.

Non-enzymatic glucose detection free of ascorbic acid interference using nickel powder and nafion sol–gel dispersed renewable carbon ceramic electrode

A new enzymeless glucose sensor has been fabricated by a nickel powder dispersed sol–gel derived ceramic graphite composite. The electrocatalytic oxidation of glucose in alkaline medium directly at nickel powder modified carbon ceramic electrode has been investigated. The modified electrode offer excellent electrocatalytic activity toward the glucose oxidation at low positive potential (0.45 V vs. Ag/AgCl, 3 M KCl). Glucose was determined chronoamperometrically at the surface of the modified electrode in pH 13. Under the optimized condition, the calibration curve is linear in the concentration range of 0.5–5000 μM. The detection limit (signal-to-noise 3) and sensitivity are 0.1 μM and 40 nA μM −1, respectively. The glucose sensor can be renewed easily in a reproducible manner by a simple polishing step and it has a long operational lifetime and short response time t 90% < 1 s. In addition, the fabrication of CCE with nafion and nickel powder was employed to eliminate the interference of ascorbic acid during the catalytic oxidation of glucose. The capability of the modified electrode for direct glucose quantification in human blood serum matrix is also discussed.