scholarly journals Critical aspects in exploring time analysis for the voltammetric estimation of kinetic parameters of surface electrode mechanisms coupled with chemical reactions

2021 ◽  
Vol 40 (1) ◽  
pp. 1
Author(s):  
Rubin Gulaboski ◽  
Valentin Mirceski ◽  
Milivoj Lovric
Keyword(s):  
Electron Transfer ◽  
Chemical Reactions ◽  
Accurate Determination ◽  
Frequency Variation ◽  
Main Concern ◽  
Square Wave ◽  
Transfer Step ◽  
Independent Analysis ◽  
Kinetics Of ◽  
Critical Aspects

The accurate determination of the rate constant related to the electron transfer step of so-called “surface redox active compounds” by voltammetric measurements is very important because it is linked to the reactivity and stability of many biological and chemical systems such as redox enzymes, vitamins, hormones, and many more. Evaluation of the kinetics of the electron transfer is often challenging, especially when chemical equilibria are coupled to the electron transfer step. In this work, we theoretically consider some critical aspects of the time-related methodologies in square-wave voltammetry (SWV), which is designed to analyze the kinetics of the electron transfer step of surface mechanisms coupled with chemical reactions. We demonstrate with a series of simulated scenarios that caution must be taken when exploring the time-related analysis for kinetic characterizations for both surface CE and EC mechanisms. The main concern stems from the fact that the SW frequency simultaneously affects both the kinetics of electron transfer and that of chemical reactions as well. Under defined conditions, the SW frequency variation in the case of surface EC and CE mechanisms may produce unexpected features of the voltammetric patterns. In many scenarios, time-independent analysis, such as those related to the square-wave amplitude and potential increment, are seen as alternative tools to evaluate the rate parameter of electrode reactions.

Currents in Biochemical Research 1956

PEDIATRICS ◽  
1958 ◽  
Vol 21 (4) ◽  
pp. 699-699
Author(s):  
SAMUEL J. FOMON
Keyword(s):  
Electron Transfer ◽  
Enzyme Activity ◽  
Chemical Reactions ◽  
The Past ◽  
Recent Developments ◽  
Living Organisms ◽  
Biochemical Research ◽  
Prosthetic Groups ◽  
Kinetics Of

Because most chemical reactions occurring in living organisms are catalyzed by enzymes and because recent developments in methodology have given great impetus to studies of these substances, it is perhaps not surprising that enzyme chemistry is prominently featured in a collection of essays recounting important advances in biochemical research during the past 10 years. The mechanism of synthesis of enzymes and of interaction between enzyme and substrate, the importance of certain of the prosthetic groups, co-enzymes and co-factors, electron transfer and kinetics of enzyme activity are all considered.

scholarly journals Photoinduced Water Oxidation at the Aqueous GaN (101̅0) Interface: Deprotonation Kinetics of the First Proton-Coupled Electron-Transfer Step

ACS Catalysis ◽  
2015 ◽  
Vol 5 (4) ◽  
pp. 2317-2323 ◽  
Author(s):  
Mehmed Z. Ertem ◽  
Neerav Kharche ◽  
Victor S. Batista ◽  
Mark S. Hybertsen ◽  
John C. Tully ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Water Oxidation ◽  
Proton Coupled Electron Transfer ◽  
Transfer Step ◽  
Kinetics Of

Kinetics of the Terminal Electron Transfer Step in Cytochrome c Oxidase

2012 ◽  
Vol 116 (6) ◽  
pp. 1876-1883 ◽  
Author(s):  
Varomyalin Tipmanee ◽  
Jochen Blumberger
Keyword(s):  
Electron Transfer ◽  
Cytochrome C ◽  
Cytochrome C Oxidase ◽  
Transfer Step ◽  
Kinetics Of

New highly efficient coulometric cell with homogenous potential distribution on the working electrode

1986 ◽  
Vol 51 (3) ◽  
pp. 636-642
Author(s):  
Michal Németh ◽  
Ján Mocák
Keyword(s):  
Chemical Reactions ◽  
Potential Distribution ◽  
Anaerobic Conditions ◽  
Highly Efficient ◽  
Working Electrode ◽  
Constant Potential ◽  
Quantitative Analyses ◽  
Mechanism And Kinetics ◽  
Kinetics Of

A highly efficient coulometric cell was designed and constructed, ensuring a constant potential over the whole surface of the working electrode and suitable for very rapid electrolysis. It consists of concentric cylindrical Teflon parts; also the working and auxiliary electrodes are cylindrical and concentric. Electrolysis can be carried out under anaerobic conditions. Functioning of the cell was tested on the oxidation of hexacyanoferrate(II) and chlorpromazine and reduction of hexacyanoferrate(III). The new cell is suitable for routine quantitative analyses and in studying the mechanism and kinetics of moderately rapid chemical reactions.

scholarly journals Amperometric Biosensors Based on Direct Electron Transfer Enzymes

Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4525
Author(s):  
Franziska Schachinger ◽  
Hucheng Chang ◽  
Stefan Scheiblbrandner ◽  
Roland Ludwig
Keyword(s):  
Electron Transfer ◽  
Electrode Materials ◽  
Direct Electron Transfer ◽  
Accurate Determination ◽  
Direct Electrochemistry ◽  
Product Analysis ◽  
Amperometric Biosensors ◽  
Chemical Surface ◽  
Fusion Enzymes ◽  
Cost Efficient

The accurate determination of analyte concentrations with selective, fast, and robust methods is the key for process control, product analysis, environmental compliance, and medical applications. Enzyme-based biosensors meet these requirements to a high degree and can be operated with simple, cost efficient, and easy to use devices. This review focuses on enzymes capable of direct electron transfer (DET) to electrodes and also the electrode materials which can enable or enhance the DET type bioelectrocatalysis. It presents amperometric biosensors for the quantification of important medical, technical, and environmental analytes and it carves out the requirements for enzymes and electrode materials in DET-based third generation biosensors. This review critically surveys enzymes and biosensors for which DET has been reported. Single- or multi-cofactor enzymes featuring copper centers, hemes, FAD, FMN, or PQQ as prosthetic groups as well as fusion enzymes are presented. Nanomaterials, nanostructured electrodes, chemical surface modifications, and protein immobilization strategies are reviewed for their ability to support direct electrochemistry of enzymes. The combination of both biosensor elements—enzymes and electrodes—is evaluated by comparison of substrate specificity, current density, sensitivity, and the range of detection.

Sign in / Sign up

Export Citation Format

Share Document