Chronocoulometric techniques in the study of computerized enzyme electrode systems

Rishpon, Judith

doi:10.1002/bit.260290210

Cited by 13 publications

(3 citation statements)

References 16 publications

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“…The working electrode potential was held at 0.22V vs. SCE. A computerized electrochemical system described earlier (27) was employed for current reading and signal averaging. The system was capable of simultaneous readings of several working electrodes in the same substrate solution, using a single reference electrode, a single counter electrode and a multiplexer (28).…”

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confidence: 99%

Immunoelectrodes for the Detection of Bacteria

Rishpon

Gezundhajt

Soussan

et al. 1992

ACS Symposium Series

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This work describes a rapid and sensitive method for the determination of bacteria. The method is based on an enzyme-taggedimmuno-electrochemical assay. Antibodies are immobilized on disposable carbon felt disc electrodes and are used to capture antigens in test solutions. After a short incubation with a second antibody, which is labeled with the enzyme alkaline phosphatase, the activity of the enzyme electrode thus formed is measured. This enzyme reacts with the substrate p-aminophenyl phosphate and the product of this enzymatic reaction, p-aminophenol, is detected amperometrically. The use of rotating electrodes significantly shortens the incubation times and, together with the computerized electrochemical system, results in extremely high sensitivity. The results obtained with Staphylococcus aereus and Escherichia coli cells show that the system can detect as low as 10 cell/ml in less than 10 minutes.There is a great need for fast and reliable devices capable of detection and identification of various types of bacteria. Traditional microbiological methods are based on cultural techniques which are tedious and slow. A considerable effort has been invested in development of detection methods based on immunological interactions. These methods, which generally involve labeling of antibodies with radioactive, fluorescent or enzymatic label, have been shown to be quite effective, giving specific and quantitative detection of target antigens. During the last decade several attempts were made to combine the specificity of antibody-antigen interaction with the high sensitivity, wide dynamic range, and simplicity of electroanalytical methods. These attempts led to the development of electrochemical immunosensors, several of which detect the corresponding antigen at extremely high sensitivity (1-5).

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confidence: 99%

Immunoelectrodes for the Detection of Bacteria

Rishpon

Gezundhajt

Soussan

et al. 1992

ACS Symposium Series

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“…For the chronoamperometry, a step potential is applied to the electrode immersed in a solution containing electroactive species and biased at a potential where no electrochemical process takes place, so that the final potential is in the diffusion-controlled region. 29 The potential is stepped from an individual value of E 1 to E 2 and the accompanying current is recorded as a function of time for an electrode in unstirred solution. 30 The current decays as the electrolysis proceeds to deplete the electroactive species near the electrode in solution.…”

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confidence: 99%

An Advanced Technique to Evaluate the Electrochromic Performances of NiO Films by Multi-Cycle Double-Step Potential Chronocoulometry

Zhou

Wang

Zhang

et al. 2016

J. Electrochem. Soc.

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NiO films with amorphous and crystalline structure are prepared via sol-gel method. The electrochromic performances are evaluated in a KOH electrolyte by cyclic voltammetry (CV), which demonstrates that the crystalline NiO thin film has excellent stability and durability compared with the amorphous film. Meanwhile, the unique method of multi-cycle double-step potential chronocoulometry (MDPC) is firstly employed to analyze the electrochromic performance of the NiO films. It shows that the cyclic tendency obtained from MDPC is consistent with the CV evolutions. The relationship between charge densities and cycles can be directly obtained by MDPC, consequently, the reversibility of films can be directly evaluated by the ratio of the extracted/inserted charges. As a primary advantage, the response charges obtained by MDPC technique can be divided into three parts including Faradic charges (Q f ) associated with redox activity leading to chromic change, the capacitive charges (Q dl ) corresponding to charging and discharging of electrodeelectrolyte double-layer capacitor, and parasitic charges (Q ads ) consumed by electrolysis of adsorbed species. The electrochromic mechanism of NiO films are further explored by analyzing the cycle dependence of Q f and Q ads evolutions. It adequately supports that MDPC has significant advantage to analyze the electrochromic performance and mechanism of electrochromic materials.

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“…This strategy is based on the covalent immobilization of enzyme molecules to the surface of transducer electrodes such as carbon (6) and platinum (7). Incorporation of enzyme molecules into electrochemically prepared conductive polymers is another new strategy for the microfabrication of enzyme electrodes (8,9).…”

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confidence: 99%

Electrochemical Fabrication of Amperometric Microenzyme Sensor

Ikariyama

Yamauchi

Yukiashi

et al. 1989

J. Electrochem. Soc.

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Enzyme electrodes were microfabricated by electrochemical incorporation of enzyme molecules into the continuously electrochemically developing micropores of platinum black particles. Two electrochemical processes, electrochemical adsorption of enzyme molecules and reductive deposition of metallic microparticles from its complexal form, were simultaneously carried out by using a microelectrode of diameter ranging from 10 to 200 ~m. An amperometric glucose sensor, consisting of a glucose oxidase-incorporated microelectrode, demonstrated high performance characteristics including high sensitivity and fast response.

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Chronocoulometric techniques in the study of computerized enzyme electrode systems

Cited by 13 publications

References 16 publications

Immunoelectrodes for the Detection of Bacteria

Immunoelectrodes for the Detection of Bacteria

An Advanced Technique to Evaluate the Electrochromic Performances of NiO Films by Multi-Cycle Double-Step Potential Chronocoulometry

Electrochemical Fabrication of Amperometric Microenzyme Sensor

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