Amperometric Determination Of Hydrogen Peroxide Research Articles

Lipid membrane immobilized horseradish peroxidase biosensor for amperometric determination of hydrogen peroxide

Stable films of didodecyldimethylammonium bromide (DDAB, a synthetic lipid) and horseradish peroxidase (HRP) were made by casting the mixture of the aqueous vesicle of DDAB and HRP onto the glassy carbon (GC) electrode. The direct electron transfer between electrode and HRP immobilized in lipid film has been demonstrated. The lipid films were used to supply a biological environment resembling biomembrane on the surface of the electrode. A pair of redox peaks attributed to the direct redox reaction of HRP were observed in the phosphate buffer solution (pH 5.5). The cathodic peak current increased dramatically while anodic peak decreased by addition of small amount H 2O 2. The pH effect on amperometric response to H 2O 2 was studied. The biosensor also exhibited fast response (5 s), good stability and reproducibility.

Ultra-Low-Volume, Real-Time Measurements of Lactate from the Single Heart Cell Using Microsystems Technology

The fabrication of microelectrodes integrated within ultra-low-volume microtiter chambers for the amperometric determination of metabolites continues to be of interest in the subject of single-cell and high-throughput screening. The microsystem described in this paper consists of a two-microelectrode sensor with a microfluidic dispensation technology, which is able to deliver both very low titers (6.5 pL) and single heart cells into a low-volume microphotoelectrochemical cell. Devices were fabricated using photolithography and liftoff giving reproducible sensors integrated within high aspect ratio titer chambers (with a volume of 360 pL), made of the photoepoxy SU8. In this paper, the determination of lactate was optimized using an enzyme-linked assay based upon lactate oxidase, involving the amperometric determination of hydrogen peroxide at +640 mV versus an internal Ag/AgCl pseudoreference. The microsystem (including the microfluidic dispensers and structures as well as the microsensor) was subsequently used to measure the lactate content of single heart cells. Dynamic electrochemical measurements of lactate during cell permeabilization are presented. We also show the use of respiratory uncouplers to simulate ischemia in the single myocyte and show that, as expected, the rate of lactate production from the hypoxic heart cell is greater than that within the normoxic healthy myocyte.

Flow-injection system with enzyme reactor for differential amperometric determination of hydrogen peroxide in rainwater

Differential determinations of hydrogen peroxide (H 2O 2) have been performed by amperometry, combining flow-injection analysis (FIA) and a tubular reactor containing immobilized enzymes. A gold microelectrode modified by electrochemical deposition of platinum was employed as working electrode. Hydrogen peroxide was quantified in rainwater using amperometric differential measurements at +0.60 V versus Ag/AgCl (sat). For the enzymatic consumption of H 2O 2, a tubular reactor containing immobilized catalase was constructed, using a novel way for immobilization of enzymes on Amberlite IRA-743 resin. The linear dynamic range in H 2O 2 extends from 1 to 100×10 −6 mol/l, at pH 7.0. At flow rate of 2.0 ml/min and injecting 150 μl sample volumes, the sampling frequency of the 90 determinations/h is afforded. The reproducibility of the current peaks for hydrogen peroxide in 10 −5 mol/l range concentration shown a R.S.D. better than 1%. The detection limit of the method is 2.9×10 −7 mol/l (1.5 ng of H 2O 2 in a 150 μl sample). The rainwater samples analyses were compared with the parallel amperometric determinations using static mercury electrode and by spectrophotometry, showing very good correlation between the three methods.

Polyelectrolyte Multilayer Film-Coated Electrodes for Amperometric Determination of Hydrogen Peroxide in the Presence of Ascorbic Acid, Uric Acid and Acetaminophen

Polyelectrolyte Multilayer Film-Coated Electrodes for Amperometric Determination of Hydrogen Peroxide in the Presence of Ascorbic Acid, Uric Acid and Acetaminophen

Mechanism of hydrogen peroxide oxidation reaction at a glassy carbon electrode in alkaline solution

The voltammetric behavior of hydrogen peroxide at a glassy carbon electrode in alkaline solution was studied. An anodic prewave, preceding the well-known transport controlled oxidation reaction of hydrogen peroxide, was observed. The voltammetric current in this wave is independent of the rotation speed of the glassy carbon disc electrode, even in what looks like a limiting current plateau, denoted by a pseudo limiting current. This current is dependent strongly on pH and temperature, does not vary linearly with hydrogen peroxide concentration and the reaction orders, with respect to hydrogen peroxide and hydroxyl ions (pH), are dependent on the hydrogen peroxide concentration. A mechanism that can explain these experimental results has been proposed. It consists of two submechanisms, occurring simultaneously at the electrode surface, which are in competition with each other. Their relative predominance is controlled by the hydrogen peroxide concentration, which can explain the varying reaction orders with respect to hydroxyl ions and hydrogen peroxide. The current equation resulting from the proposed mechanism shows the possibility of using the studied electrode reaction for the amperometric determination of hydrogen peroxide up to high concentrations.

Sol-gel thin-film immobilized soybean peroxidase biosensor for the amperometric determination of hydrogen peroxide in acid medium.

An acid-stable soybean-peroxidase biosensor was developed by immobilizing the enzyme in a sol-gel thin film. Methylene blue was used as a mediator because of its high electron-transfer efficiency. The sol-gel thin film and enzyme membrane were characterized by FT-IR, and the effects of pH, operating potential, and temperature were explored for optimum analytical performance by using the amperometric method. The H2O2 sensor exhibited a fast response (5 s), high sensitivity (27.5 microA/mM), as well as good thermostability and long-term stability. In addition, the performance of the biosensor was investigated using flow-injection analysis (FIA).

Amperometric Determination of Hydrogen Peroxide by Utilizing a Sol-Gel-Derived Biosensor Incorporating an Osmium Redox Polymer as Mediator

ABSTRACT An amperometric sol-gel-derived biosensor for the detection of hydrogen peroxide was constructed by immobilizing horseradish peroxidase(HRP) and an osmium redox polymer([Os(bpy)2(PVP)10Cl]Cl; abbreviated Os-polymer) as mediator. Upon addition of hydrogen peroxide to the solution, a bioelectrocatalytic reduction current wave was observed. The steady-state hydrogen peroxide catalytic reduction current reached a plateau at 150 mV vs, Ag/AgCl and hydrogen peroxide could be determined amperometrically with good sensitivity at -50 mV vs. Ag/AgCl. This biosensor exhibits a rapid response(t(95%)=10 s) on addition of 1.0 mM hydrogen peroxide. The linear response range, apparent Michaelis-Menten constant(Km'), and detection limit were 0.01 ∼ 2.7 mM, 5.93 mM, and 0.005 mM, respectively. Uric acid, dopamine, ascorbic acid, paracetamol were found not to interfere at this potentials. The biosensor was found to be stable for 1 month on storage at 4°C.

Amperometric determination of hydrogen peroxide with a manganese dioxide film-modified screen printed carbon electrode

A carbon thick film electrode modified with an MnO2-film is investigated as an amperometric detector for hydrogen peroxide in flow-injection analysis (FIA). At an operating potential of +0.48 V vs. Ag/AgCl catalytic oxidation of the analyte is exploited for amperometric monitoring. Experimental parameters, such as pH of the carrier, working potential, flow rate and injection volume, are optimized. The amperometric signals are linearly proportional to the concentration of H2O2 in the range from 0.005 to 10 mg/L, showing a detection limit (3σ) of 2.3 μg/L. The method is applied to the determination of H2O2 in rain water and to a simple assay to quantify glucose in human plasma.

Chrono amperometric determination of hydrogen peroxide in swimming pool water using an ultramicroelectrode array

Abstract Ultramicroelectrode arrays have been applied for monitoring the disinfectant hydrogen peroxide in swimming pool water. The sensors were manufactured using silicon thin-film technology. Each consisted of nine miniaturized platinum working electrodes connected in parallel. A platinum counter electrode and a silver/silver chloride reference electrode completed the measuring setup. The ultramicroelectrode arrays were characterized by cyclic voltammetry and chrono amperometry. The sensor properties could be improved and the interfering influence of the swimming pool water matrix was reduced by covering the working electrodes of the arrays with NAFION™ membranes. A comparison of the introduced chrono amperometric method using the ultramicroelectrode array with the German standard method (DIN) for the hydrogen peroxide determination showed that the accuracy of the NAFION™ coated sensors is suitable for monitoring and controlling the hydrogen peroxide concentration in swimming pool waters.

Peroxidase‐based amperometric sensor of hydrogen peroxide generated in oxidase reaction: Application to creatinine and creatine assay

AbstractPeroxidase (POD) was entrapped on a ferrocene (Fc)‐embedded carbon paste (CP) electrode with a dialysis membrane to construct a POD‐Fc‐CP electrode for the reductive amperometric determination of hydrogen peroxide (H2O2). The electrode allowed the H2O2 detection down to 10 nM (under stirring), with a linear relation up to 15 μM, and without change of the response over one month. On the other hand, a plastic‐formed carbon (PFC) electrode can donate electrons to POD without any specific mediator. The POD‐entrapped PFC electrode produced a relative current density of 24% compared with the POD‐Fc‐CP electrode. The reductive detection of H2O2 with the POD‐Fc‐CP electrode was applied to the determination of creatinine and creatine in serum and urine using sarcosine oxidase, creatine amidinohydrolase, and creatinine amidohydrolase as the reagents. The significance of the membrane‐covered POD‐Fc‐CP electrode in the coupling of the oxidase reaction is also discussed.

Reagentless Amperometric Determination of Hydrogen Peroxide by Silica Sol–Gel Modified Biosensor

A sensitive amperometric hydrogen peroxide biosensor was developed based on the immobilization of horseradish peroxidase (HRP) enzyme by the sol–gel method on a carbon paste electrode in a ‘sandwich configuration’. The configuration of the biosensor is a carbon paste/sol–gel–ferrocene/HRP/sol–gel. The biosensor has a fast response with a linear calibration range of 3–57 µmol dm–3 with a sensitivity of 0.067 µA µmol–1 (correlation coefficient 0.996). Based on a signal-to-noise ratio of 3, the detection limit of the biosensor is 0.6 µmol dm–3. The lifetime, fabrication reproducibility and measurement reproducibility were evaluated and an interference study was carried out. Recoveries measured by the biosensor in various samples were satisfactory.

Amperometric determination of hydrogen peroxide by direct and catalytic reduction at a copper electrode

In a buffer solution at ambient temperature and dissolved oxygen concentration, pH 6.7, copper electrodes could be cycled between the Cu(0)/Cu(II) redox states, by cycling the potential between −0.8 and +0.3 V vs. SCE. At 1 V s −1, the reduction of Cu(II) proceeded with a rate constant of 12.3 s −1 ( α C = 0.16, α A = 0.93). The redox couple catalysed the reduction of hydrogen peroxide, with a second-order rate constant of approx. 25 ± 10 M −1 s −1. Amperometric determination of H 2O 2 at −0.25 V gave a limit of detection (2 × noise) of 1.2 μM (sensitivity = 0.211 mA mM −1 cm −2 up to 2.0 mM), with a response time (steady-state) of 3 to 4 s. A 1 μM change in the O 2 concentration gave approx. a 0.04% change in the H 2O 2 sensitivity. The presence of H 2O-soluble copper-complexing anions at low concentrations gave a change in the H 2O 2 response. At higher anion concentrations (> 20 mM), the rate of electron transfer from the metal was faster than the rate of Cu(II) dissolution. A copper micro-band electrode was used to determine H 2O 2 in a mixture of glacial acetic acid and chloroform.

Flow injection amperometric determination of hydrogen peroxide by oxidation at an iridium oxide electrode

Either an iridium electrode that was anodically pretreated or a glassy carbon electrode that was coated with a film that contained iridium oxide promoted the oxidation of hydrogen peroxide. With flow injection methodology, linear calibration curves were obtained over the 2 × 10 −5 −3.6 × 10−8 M range with 0.1 M KOH as the carrier. With solutions of pH ⩾ 11, oxidation occurred at applied potentials of near 0.0 V vs. SCE, which is much lower than potentials needed at bare Pt or glassy carbon. The low overpotential suggests applications to systems where oxidation of other species limits the use of bare electrodes. Cyclic voltammetric studies show that HO 2 − is the electroactive species and that catalysis rather than mediation promotes the charge transfer. Dissolved oxygen does not interfere with the measurement.

Flow Injection Amperometric Determination of Hydrogen Peroxide at Low Level in Aqueous Solution

Abstract A method is proposed for the flow-injection amperometric determination of hydrogen peroxide. Iodine is generated, by injecting hydrogen peroxide solution into an eluent 0.2 M in potassium iodide and 1 Min sulphuric acid and 5×10−3M in Mo(VI) and is monitored at a platinum electrode that is being held at 0.1 V versus SCE. the rectilinearity range is from 10−3−10−6 M and the method is simple, accurate and compared favourably with the titrimetric method involving starch as indicator.

An investigation of the influences of the background material and layer thickness of sputtered palladium/gold on carbon electrodes for the amperometric determination of hydrogen peroxide

Electrochemical detection of hydrogen peroxide by different graphite and carbon electrodes, modified with a catalyst layer of a mixture of vacuum-deposited palladium and gold, is described. The influences of background electrode material and layer thickness of the catalyst were investigated. Graphite and carbon are more efficient than glassy carbon as background electrode material. At least 200 Å of the catalyst are necessary to obtain a fully catalytic electrode. The overvoltages for both the oxidation and the reduction could be decreased by at least 800 mV. Straight calibration curves were obtained between 10 −7 −5 × 10 −3 M hydrogen peroxide when electrodes were used as amperometric sensors in a FIA system.

A carbon electrode sputtered with palladium and gold for the amperometric detection of hydrogen peroxide

A modified carbon electrode for the amperometric determination of hydrogen peroxide is described. By deposition of a 15-nm thick layer of a 40:60 mixture of palladium and gold on the surface of the electrode the overvoltages for both the oxidation and the reduction can be decreased by at least 800 mV. When applied as an electrochemical sensor in a flow-injection system, linear calibration graphs were obtained between 10 −7 and 5 × 10 −3 M hydrogen peroxide. The modified electrodes were stable for months.

Amperometric determination of hydrogen peroxide in pickling baths for copper and copper alloys by flow injection analysis

The hydrogen peroxide is oxidized at + 1.5 V vs. SCE at a glassy carbon electrode of the wall-jet type. The samples are diluted about 100 times in a dispersion coil before entering the amperometric detector. The calibration curve is linear from 10 −4 to 1 M H 2O 2, when 5-μl samples are used. With 50-μl samples the detection limit decreases to 10 −6 M H 2O 2. Neither metal ions (Cu 2+, Zn 2+, Ni 2+, Al 3+) up to 0.5 M nor changes in the sulfuric acid concentration of the samples between 0.1 and 1 M interfere with the hydrogen peroxide determination. About 75 samples can be analyzed per hour.

A new catalytic electrode for the amperometric determination of hydrogen peroxide

The electrode is based on the decomposition of H 2O 2 by an inorganic polymer catalyst. The steady -state decomposition currents of H 20 2 obtained with the catalyst electrode are independent of ionic strength (0.1–1.5) and pH (2.5–10.5). A linear relationship is obtained from 0.02 to 2 mM H 20 2 in 0.1 M KCl at 25°C.

Amperometric determination of hydrogen peroxide with potassium permanganate in the presence of fluoride ions

Amperometric determination of hydrogen peroxide with potassium permanganate in the presence of fluoride ions