Electrode For Detection Of Hydrogen Peroxide Research Articles

Molybdenum-containing polypyrrole self-supporting hollow flexible electrode for hydrogen peroxide detection in living cells

A flexible electrode based on polypyrrole-supported free-standing molybdenum oxide-molybdenum disulfide/polypyrrole nanostructure (MoO3–MoS2/PPy) was synthesized. The petal-like MoO3–MoS2 sheets grown on PPy were prepared step by step through simple electrodeposition and hydrothermal methods. The corresponding surface morphological and structural characterizations were characterized by field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The results showed that the prepared petal MoO3–MoS2 hybrid nanomaterials were uniformly distributed on the PPy skeleton and exhibited a three-dimensional porous network structure. The flexible electrode was used for non-enzymatic detection of hydrogen peroxide (H2O2), and the developed MoO3–MoS2/PPy nanomaterials exhibited high electrochemical sensing performance in the range of 0.3–150 μM, with the detection limit of 0.18 μM (S/N = 3). The excellent detection properties enabled the MoO3–MoS2/PPy flexible electrode to detect H2O2 released by living cells. The resulting MoO3–MoS2/PPy flexible electrode also has the advantages of customizable shape and adjustability, which provides a potential platform for constructing clinically diagnosed in vivo portable instruments and real-time environmental monitoring.

Catalase-Based Modified Graphite Electrode for Hydrogen Peroxide Detection in Different Beverages.

A catalase-based (NAF/MWCNTs) nanocomposite film modified glassy carbon electrode for hydrogen peroxide (H2O2) detection was developed. The developed biosensor was characterized in terms of its bioelectrochemical properties. Cyclic voltammetry (CV) technique was employed to study the redox features of the enzyme in the absence and in the presence of nanomaterials dispersed in Nafion® polymeric solution. The electron transfer coefficient, α, and the electron transfer rate constant, k s, were found to be 0.42 and 1.71 s−1, at pH 7.0, respectively. Subsequently, the same modification steps were applied to mesoporous graphite screen-printed electrodes. Also, these electrodes were characterized in terms of their main electrochemical and kinetic parameters. The biosensor performances improved considerably after modification with nanomaterials. Moreover, the association of Nafion with carbon nanotubes retained the biological activity of the redox protein. The enzyme electrode response was linear in the range 2.5–1150 μmol L−1, with LOD of 0.83 μmol L−1. From the experimental data, we can assess the possibility of using the modified biosensor as a useful tool for H2O2 determination in packaged beverages.

A non-enzymatic hydrogen peroxide sensor based on vertical NiO nanosheets supported on the graphite sheet

In this study, a non-enzymatic hydrogen peroxide sensor was fabricated by directly growing vertically aligned NiO nanosheets on the graphite sheet through a simple, effective process, i.e. the surfactant-templated method. Compared with most of the reported hydrogen peroxide sensor through drop-coating method, our sensor exhibits a higher sensitivity and a good stability, resulting from the vertically aligned NiO nanosheets and method features. The as-prepared sensor exhibited a detection limit of 0.4μM (at signal/noise=3), a good reproducibility (relative standard deviation (RSD) of 3.36%), a wide linear range (up to 4.0mM) with a sensitivity of 1077μAmM−1cm−2 under the optimal conditions. Furthermore, the as-prepared sensor also showed excellent selectivity and stability for hydrogen peroxide detection. This study provides a promising electrochemical electrode for hydrogen peroxide detection by a facile method.

Copper hexacyanoferrate modified electrodes for hydrogen peroxide detection as studied by X-ray absorption spectroscopy

X-ray absorption spectroscopy (XAS) has been used to monitor the local geometry of Fe and Cu sites of copper hexacyanoferrates (CuHCF)-modified electrodes which find application in the electrochemical detection of hydrogen peroxide. The XAS approach has permitted to check the nature of the Cu and Fe sites and to investigate their local structure around about 500 pm from the metal centres. The measurements have been done on electrodes prior and after the addition of known quantities of hydrogen peroxide at two different concentration ranges, following a protocol consisting of H2O2 addition, applied potential, and rest period. For the CuHCF-modified electrode, this protocol leads to the increasing conversion to an already present “inactive” component, which limits the usability of the sensor; whereas the electrode modified with the Cu2+-loaded CuHCF displays a better resistance to this unavoidable process. In particular, the formation of the “inactive” component takes place more slowly, confirming the capability, at molecular scale, of such Cu-enriched CuHCF used as electrode modifier to detect more efficiently hydrogen peroxide, as recently demonstrated in our previous paper.

A photoelectrochemical sensor based on nickel hydroxyl-oxide modified n-silicon electrode for hydrogen peroxide detection in an alkaline solution

A novel photoelectrochemical hydrogen peroxide (H2O2) sensor was constructed with platinum (Pt) and nickel hydroxyl-oxide (NiOOH) double layers modified n-silicon electrode (NiOOH/Pt/n–n+-Si). About 40nm Pt layer and about 100nm Ni layer were successively coated on the front surface of n–n+-Si (111) wafers by vacuum evaporating. A stable layer of NiOOH was formed through oxidation of the Ni layer on the coated silicon wafer by the electrochemical method. The surface of modified electrode was characterized by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The NiOOH/Pt/n–n+-Si electrode has been used for determination of H2O2 with a two-electrode cell in the absence of reference electrode by photocurrent measurement at a zero bias. The photoelectrochemical sensor showed a good linear response to H2O2 concentrations in a range from 1.0×10−5 to 6×10−5M with a determination limit (S/N=3) of 2.2μM. The NiOOH/Pt/n–n+-Si electrode exhibited excellent reproducibility and stability. Particularly, the facile measurement requirements made this novel modified electrode promising for the development of outdoor H2O2 sensors.

Electrochemiluminescence of luminol at the titanate nanotubes modified glassy carbon electrode

A new strategy for the construction of a sensitive and stable electrochemiluminescent platform based on titanate nanotubes (TNTs) and Nafion composite modified electrode for luminol is described, TNTs contained composite modified electrodes that showed some photocatalytic activity toward luminol electrochemiluminescence emission, and thus could dramatically enhance luminol light emission. This extremely sensitive and stable platform allowed a decrease of the experiment electrochemiluminescence luminol reagent. In addition, in luminol solution at low concentrations, we compared the capabilities of a bare glassy carbon electrode with the TNT composite modified electrode for hydrogen peroxide detection. The results indicated that compared with glassy carbon electrode this platform was extraordinarily sensitive to hydrogen peroxide. Therefore, by combining with an appropriate enzymatic reaction, this platform would be a sensitive matrix for many biomolecules.

From DVD to dendritic nanostructure silver electrode for hydrogen peroxide detection

A facile method of multi-potential step-scan has been employed to fabricate the dendritic silver nanostructures on a silver thin film based digital video disc (DVD) electrode. The morphologies of the nanostructures, the chemical composition, and the crystal structure have been characterized by field-emission scanning electron microscopy, energy-dispersed x-ray spectroscopy, and x-ray diffraction, respectively. The electrocatalytic activity of the resulting electrode toward the electro-reduction of hydrogen peroxide (H2O2) has been examined via cyclic voltammetry and amperometric analysis. The excellent linear relationship between current response and H2O2 concentration is observed in the range from 5.88×10−7 to 6.73×10−5molL−1 and the detection limit is 2×10−7molL−1 (S/N=3). The as-developed method has been employed to determine H2O2 concentration in real samples.

Copper Nanoparticles with Copper Hexacyanoferrate and Poly(3,4-ethylenedioxythiophene) Hybrid Film Modified Electrode for Hydrogen Peroxide Detection

Copper Nanoparticles with Copper Hexacyanoferrate and Poly(3,4-ethylenedioxythiophene) Hybrid Film Modified Electrode for Hydrogen Peroxide Detection

NiO/MWCNTs Coated F-doped Tin Oxide Working Electrode for Hydrogen Peroxide Detection

Abstract In this work, NiO/MWCNTs composites were synthesized by heat treatment via two methods. MWCNTs was treated by classical oxidative with acid. The treated MWCNTs was mixed with Nickel acetate in various concentration before calcined at 400 °C for 2 h to obtain the NiO/MWCNTs and compared with another method that prepared by chemically depositing nickel hydroxide onto carbon nanotubes under microwave irradiation and thermal annealing process. The modified electrode for the detection of hydrogen peroxide was successfully developed on cross-linking between NiO/MWCNTs nanocomposites and fluorine-doped tin oxide (FTO) using nafion as binder. The physical properties of the composites were investigated by Field Emission Scanning Electron Microscope (FE-SEM) and X-ray Diffractometer (XRD). The SEM results indicated that NiO nanoparticles were well distributed on the surface of MWCNTs. The cyclic voltammetry were used to confirm the successful procedure synthesis of NiO/MWCNTs/FTO and the concentration of hydrogen peroxide was determined by amperometry, by mean of the NiO/MWCNTs/nafion/FTO as working electrode.

Multilayer CuHCF films bridged by CuMPCs for H2O2 detection

Multilayer copper hexacyanoferrate (CuHCF) films bridged by cysteine monolayer protected copper clusters (CuMPCs) were prepared by the sequential electrochemical cyclcing and dipping process. Cyclic voltammetry, scanning electron microscopy (SEM) and atomic force microscopy (AFM) were used to characterize the formation of the multilayer films. Cyclic voltammetric measurements indicated that the films grew exponentially with the increase of the layer numbers. AFM and SEM images revealed that the obtained films were thin and exhibited a three-dimensional structure. The nanostructured thin-film assemblies exhibited interesting catalytic properties that could be applied in important sensing and catalysis. Good catalytic activity and stability of the film modified electrode for hydrogen peroxide detection was studied.

Polyester sulphonic Acid interstitial nanocomposite platform for peroxide biosensor.

A novel enzyme immobilization platform was prepared on a platinum disk working electrode by polymerizing aniline inside the interstitial pores of polyester sulphonic acid sodium salt (PESA). Scanning electron microscopy study showed the formation of homogeneous sulphonated polyaniline (PANI) nanotubes (∼90 nm) and thermogravimetric analysis (TGA) confirmed that the nanotubes were stable up to 230 °C. The PANI:PESA nanocomposite showed a quasi-reversible redox behaviour in phosphate buffer saline. Horseradish peroxidase (HRP) was immobilized on to this modified electrode for hydrogen peroxide detection. The biosensor gave a sensitivity of 1.33 μA (μM)-1 and a detection limit of 0.185 μM for H2O2. Stability experiments showed that the biosensor retained more than 64% of its initial sensitivity over four days of storage at 4 °C.

Fabrication and characterisation of novel screen-printed tubular microband electrodes, and their application to the measurement of hydrogen peroxide

A new method of using screen-printed carbon electrodes (SPCEs) incorporating the electrocatalyst cobalt phthalocyanine (CoPC) for the manufacture of tubular microband electrodes for hydrogen peroxide detection is described. Characterisation of these electrodes using potassium ferrocyanide, with cyclic voltammetry, has shown that steady state behaviour is displayed which is indicative of microelectrode behaviour. The current density obtained from the voltammogram was compared to that obtained for a conventional sized CoPC–SPCE, and the values were 5618 and 35.65 Ac m −2 , respectively. Cyclic voltammetry was carried out for the same electrodes, using 7 mM H2O2 prepared in phosphate buffer at scan rates between 1 and 50 mV s −1 and no significant increase in current response was observed. The application of these tubular microband CoPC–SPCEs, to the measurement of H2O2 using chronoamperometry was investigated. A calibration study was performed and the plot showed a sensitivity value of 252 Am M −1 cm −2 and a lower detection limit of 70M. We have shown that the chronoamperometric current response could be calculated using a modified equation originally developed for a plain microband electrode. This study provides a platform for using screen-printed carbon electrodes for the fabrication of oxidase based microbiosensors, for the determination of a variety of cellular metabolites. © 2007 Elsevier Ltd. All rights reserved.

Electroanalytical applications of Prussian Blue and its analogs

The applications of transition metal hexacyanoferrates in electroanalysis are surveyed. Prussian Blue (ferric hexacyanoferrate) is recognized as the most promising low-potential transducer for hydrogen peroxide reduction among all known systems. The advantages of Prussian Blue over platinum or peroxidase electrodes for hydrogen peroxide detection are discussed. Various types of biosensors based on transition metal hexacyanoferrates and oxidase enzymes are considered. Amperometric biosensors based on Prussian Blue-modified electrodes allow the detection of glucose and glutamate down to 10–7 mol L–1 in the flow-injection mode. The future prospects of Prussian Blue-modified electrodes in analytical chemistry for the monitoring of chemical toxic agents, in clinical diagnostics, and in food control are outlined.

Concentration of extracellular L-glutamate released from cultured nerve cells measured with a small-volume online sensor.

An online sensor with a low detection limit for L-glutamate was developed in order to monitor the change in the extracellular L-glutamate concentration as a result of stimulated release from cultured nerve cells. The sensor consisted of a microdialysis (MD) probe fixed at the manipulator, a small-volume L-glutamate oxidase enzymatic reactor (0.75 mm i.d. and 2.5 cm long), and an electrochemical detector in a thin-layer radial flow cell with an active volume of 70-340 nL. Glassy carbon bulk or carbon film ring-disk electrodes were used as detectors by modifying them with Os poly(vinylpyridine) mediator containing horseradish peroxidase. The overall efficiency of L-glutamate detection with the sensor is 94% under optimum conditions, due to an efficient enzymatic reaction in the reactor and a high conversion efficiency in the radial flow cell. As a result, we achieved a sensitivity of 24.3 nA/muM and a detection limit of 7.2 nM (S/N = 3). The effect of interferents such as L-ascorbic acid can be minimized effectively by applying a low potential to the electrode for hydrogen peroxide detection (O mV) and via the ring-disk electrode geometry by using the disk for preoxidation. In the in vitro experiment, an MD probe for sampling was connected to a manipulator that controls distance between the probe and the stimulated cells. The cells were stimulated by KCl in a glass capillary or electrically with microarray film electrodes fabricated on a substrate. By using the sensor, we can monitor L-glutamate concentration changes at the submicromolar level caused by KCl stimulation of a single nerve cell and micromolar L-glutamate concentration increases caused by electrical stimulation of a brain slice. An increase in L-glutamate concentration can also be measured by positioning the probe near the cell that is connected synaptically to the stimulated cell.

An enzyme electrode for hydrogen peroxide detection based on peroxidase immobilized on a glassy carbon electrode

Horseradish peroxidase (EC 1.11.1.7) was immobilized on a polytryptophan film by (i) covalent coupling and by (ii) glutaraldehyde cross-linking. Covalent coupling was done by (i) carbodiimide on an activated bare electrode and also by (ii) glutaraldehyde coupling to a polytryptophan film. The polytryptophan film was formed by electropolymerization of tryptophan from acid solution (H 2SO 4) with a cross-linker (spermine). The film formed was electrically conducting, as proven by impedance studies. The enzyme can be coupled to this film by covalent coupling with glutaraldehyde. Impedance studies and cyclic voltammetric studies of this electrode suggest that the film may be useful in a variety of applications.