Biosensor For Detection Of Glucose Research Articles

Graphene, carbon nanotubes, zinc oxide and gold as elite nanomaterials for fabrication of biosensors for healthcare.

Technological advancements worldwide at rapid pace in the area of materials science and nanotechnology have made it possible to synthesize nanoparticles with desirable properties not exhibited by the bulk material. Among variety of available nanomaterials, graphene, carbon nanotubes, zinc oxide and gold nanopartilces proved to be elite and offered amazing electrochemical biosensing. This encourages us to write a review which highlights the recent achievements in the construction of genosensor, immunosensor and enzymatic biosensor based on the above nanomaterials. Carbon based nanomaterials offers a direct electron transfer between the functionalized nanomaterials and active site of bioreceptor without involvement of any mediator which not only amplifies the signal but also provide label free sensing. Gold shows affinity towards immunological molecules and is most routinely used for immunological sensing. Zinc oxide can easily immobilize proteins and hence offers a large group of enzyme based biosensor. Modification of the working electrode by introduction of these nanomaterials or combination of two/three of above nanomaterials together and forming a nanocomposite reflected the best results with excellent stability, reproducibility and enhanced sensitivity. Highly attractive electrochemical properties and electrocatalytic activity of these elite nanomaterials have facilitated achievement of enhanced signal amplification needed for the construction of ultrasensitive electrochemical affinity biosensors for detection of glucose, cholesterol, Escherichia coli, influenza virus, cancer, human papillomavirus, dopamine, glutamic acid, IgG, IgE, uric acid, ascorbic acid, acetlycholine, cortisol, cytosome, sequence specific DNA and amino acids. Recent researches for bedside biosensors are also discussed.

Glucose oxidase immobilized PANI cladding modified fiber optic intrinsic biosensor for detection of glucose

In the present study, we report design, development and study of polyaniline (PANI) cladding modified fiber optic intrinsic glucose biosensor (FOIGB) for glucose sensing applications. Chemically and biologically sensitive material PANI has been exploited for the preparation of sensing element by cladding modification technique. Enzyme-glucose oxidase (GOx) was immobilized on porous supportive matrix of PANI using glutaraldehyde as a cross-linking agent. As-synthesized and deposited PANI film on fiber optic core was characterized by ultraviolet–visible and Fourier transform infra-red spectroscopies. X-ray diffraction and field emission scanning electron microscopy were employed to study structure and morphology of modified cladding. Sensing parameters, such as modal power distribution (MPD), sensing response, selectivity and stability were analyzed in order to study the performance of sensor. These parameters were determined by measuring change in optical power and MPD. The sensor, stored at a temperature 4°C, showed lowest detection limit of 10nM and found stable up to 36 days. It also showed good selectivity toward glucose and stability with high result reproducibility.

A novel ECL biosensor based on C60 embedded in tetraoctylammonium bromide for the determination of glucose

A highly sensitive electrochemiluminescence (ECL) biosensor for glucose detection has been developed through immobilizing glucose oxidase (GOD) on a glassy carbon electrode (GCE) modified with C60 embedded in tetraoctylammonium bromide (TOAB+) film. C60 is a promising electron transfer mediator between GOD and GCE surface. Meanwhile, C60 has excellent catalytic performance to directly enhance the ECL intensity of luminol. In addition, the introduction of C60 and TOAB+ can immobilize more enzymes effectively onto the electrode so that they can enhance the sensitivity and detection limit of ECL biosensor. Under the optimum condition, the developed glucose biosensor exhibited the linear response range from 500nM to 13mM with a detection limit of 166.7nM (at the signal-to-noise ratio of 3). The biosensor offers an alternative analytical method with excellent properties of high selectivity, long-term stability and outstanding reproducibility.

One-dimensional copper oxide nanotube arrays: biosensors for glucose detection

One dimensional CuO nanotube (NT) arrays were synthesized by an anodization method and evaluated for glucose detection. The CuO NT arrays electrode showed enhanced activity with a sensitivity of 1.89 mA mM−1 cm−2 and a linear range from 5 μM to 3.0 mM compared with CuO nanorod (NR) arrays due to its larger surface area and faster biomolecule diffusion. Furthermore, the proposed biosensor exhibited excellent stability, high reproducibility and high selectivity for the detection of glucose, and had been successfully applied to determine glucose levels in human plasma samples with satisfactory results. The success of this work indicates the perspective of this kind of CuO electrode for further design and microfabrication of bioelectrochemical nanodevices.

An amperometric biosensor for glucose detection from glucose oxidase immobilized in polyaniline–polyvinylsulfonate–potassium ferricyanide film

In this study, a novel amperometric glucose biosensor with immobilization of glucose oxidase on electrochemically polymerized polyaniline–polyvinylsulphonate–potassium ferricyanide (Pani–Pvs–Fc) films has been accomplished via the entrapment technique. Potassium ferricyanide was used as the mediator. Determination of glucose was carried out by the oxidation of potassium ferrocyanide at 0.3 V vs. Ag/AgCl. The effects of pH and temperature were investigated, and the optimum pH value was found to be 7.5. The storage stability and the operational stability of the enzyme electrode were also studied.

A high selective disposable biosensor based on screen-printed technique with two working electrodes for eliminating interference signals

A novel disposable biosensor containing a detection electrode and a control electrode was constructed by the screen-printing techniques. The detection electrode was covered with the enzyme ink to measure the oxidation currents of the catalytic substrate, while the control electrode was coated with non-enzyme ink to monitor the interference signals. The net catalytic currents of the enzyme electrode can be obtained from the response differences of the two recording electrodes. The biosensor for detection of glucose in blood sample showed a good linear relationship in the range of 0.5–50mM (R=0.9986) with a detection limit of 0.05mM (S/N=3), and displayed a high selectivity. The general applicability of the biosensor was demonstrated by successfully using it for detecting uric acid in blood sample. The proposed biosensor possesses a high selectivity and accuracy for detecting species in biological samples, which opens the possibility of developing screen-printed electrode-based devices for bioanalysis.

A novel bi-protein bio-interphase of cytochrome c and glucose oxidase: Electron transfer and electrocatalysis

Glucose oxidase (GOD) and cytochrome c (Cyt c) were co-entrapped in the poly(diallyldimethylammonium chloride)–graphene nanosheets–gold nanoparticles (PDDA–Gp–AuNPs) hybrid nanocomposites modified glassy carbon electrode to prepare a novel bi-protein bio-interphase. Electron transfer and electrocatalysis of the bi-protein bio-interphase were investigated in detail. The results showed that the PDDA–Gp–AuNPs nanocomposites accelerated the electron transfer between proteins and electrode. The bi-protein exhibited effective direct electron transfer (DET) reaction with an apparent rate constant (ks) of 2.36s−1. The optimal molar ratio and total amount of Cyt c and GOD in the bio-interphase for DET of GOD was estimated to be about 3:1 and 1.40nmol, respectively. The bi-protein bio-interphase could be used to detect glucose based on the consumption of O2 with the oxidation of glucose catalyzed by GOD. The resulted biosensor exhibits wide linear range from 2.0 to 18.0mM. Thus, this study not only successfully achieved DET of GOD, but also constructed a novel biosensor for glucose detection.

Nanomaterial-based composite biosensor for glucose detection in alcoholic beverages

A composite electrode was prepared by modifying glassy carbon micro particles with gold nanoparticles and glucose oxidase enzyme for glucose detection. In terms of analytical characteristics, a linearity was obtained in the concentration range between 50.0 and 1000.0 µM with equation of y = 0.0015x + 0.2336 with the correlation coefficient of R2 = 0.9801. R.S.D. value was calculated for 400 µM glucose (n = 6) and found to be 4.89%. LOD and LOQ values were also calculated and revealed to be 52.9 µM and 176.3 µM, respectively. The developed system was also applied for detection of glucose in four types of alcoholic beverages.

Osmium Bipyridine-Containing Redox Polymers Based on Cellulose and Their Reversible Redox Activity

Thermo-, pH-, and electrochemical-sensitive cellulose graft copolymers, hydroxypropyl cellulose-g-poly(4-vinylpyridine)-Os(bipyridine) (HPC-g-P4VP-Os(bpy)), were synthesized and characterized. The electrochemical properties of the resulting material were investigated via cyclic voltammetry by coating the graft copolymers on the platinized carbon electrode. The results indicated that the electrochemical properties of the graft copolymer modified electrode were responsive to the pH values of the electrolyte solution. The reversible transformation between the active and inactive state originated from the changes in the architecture of the HPC-g-P4VP-Os(bpy) graft copolymer at different pH values. At high pH (e.g., above the pK(a) of P4VP), the chains of P4VP collapsed, and the electrochemical activity of the electrode was reduced. With immobilization of glucose oxidase (GOx) on the graft copolymer decorated electrode, a biosensor for glucose detection was prepared. The current of the biosensor depended on the glucose concentration in the detected solution and increased with the successive addition of glucose.

An enzyme-free quartz crystal microbalance biosensor for sensitive glucose detection in biological fluids based on glucose/dextran displacement approach

A sensitive and facile quartz crystal microbalance (QCM) biosensor for glucose detection in biological fluids was developed by means of a displacement-type assay mode between glucose and its analogy dextran for concanavalin A (ConA) binding sites on a graphene-based sensing platform. To construct such a displacement-based sensor, phenoxy-derived dextran (DexP) molecules were initially assembled onto the surface of graphene-coated QCM probe via π–π stacking interaction, and ConA molecules were then immobilized on the dextran through the dextran-ConA interaction. Upon addition of glucose, the analyte competed with the dextran for the ConA, and displaced it from the QCM probe, leading to a change in the frequency. Under optimal conditions, the frequency change relative to the basic resonant frequency was proportional to glucose concentration, and exhibited a dynamic range from 0.01 to 7.5 mM with a low detection limit (LOD) of 5.0 μM glucose (at 3 σ). The relative standard deviations (RSDs) were below 6.2% and 9.0% for the reproducibility and selectivity of the QCM glucose sensors, respectively. In addition, the assay system was evaluated with glucose spiking samples into the distilled water and blank cattle serum, receiving in excellent correlation with the referenced values.

Filmes de nanodiamantes para aplicações em sistemas eletroquímicos e tecnologia aeroespacial

NANODIAMOND FILMS FOR APPLICATIONS IN ELECTROCHEMICAL SYSTEMS AND AERONAUTICS AND SPACE TECHNOLOGY. The goal of this work is to show the use of undoped nanodiamond films as a new material for electrochemical and aerospace applications. Correlation between the applications and physico-chemical features of nano and conventional CVD polycrystalline diamond films are presented. An important and innovative application of these nanodiamonds is organic electrosynthesis, including pharmaceutical and water disinfection products, as well as electroanalytical applications, for example, development of biosensors for detection of glucose, glutamate and dopamine. In aeronautics and space developments, these nanodiamonds could be used as electrodes in rechargable batteries and in tribological investigations.

Soluble functionalized carbon nanotube/poly(vinyl alcohol) nanocomposite as the electrodefor glucose sensing

Carbon nanotubes exhibit excellent properties which make them a good candidateas the electrode material for bioapplications. A soluble functionalized carbonnanotube/poly(vinyl alcohol) nanocomposite was synthesized via esterification reactions.The obtained nanocomposite exhibits significantly improved electrical conductivity.Nanocomposite-based electrodes were prepared by a thick film technique and theirperformances were electrochemically characterized. After enzyme immobilization, they canbe used as biosensors for glucose detection. Preliminary results show these nanotubecomposite-based electrodes exhibit good electrochemical performance for glucose detection.Comparison was also made between graphite and nanocomposite-based electrodes.