Electrochemical determination of kinetic parameters of surface confined redox probes in presence of intermolecular interactions by means of Cyclic Voltammetry. Application to TEMPO monolayers in gold and platinum electrodes

2021 ◽  
Vol 365 ◽  
pp. 137331
Author(s):  
J. Gonzalez ◽  
J.A. Sequí-Castellano
Keyword(s):  
Cyclic Voltammetry ◽  
Kinetic Parameters ◽  
Intermolecular Interactions ◽  
Electrochemical Determination ◽  
Platinum Electrodes

scholarly journals Electrochemical Determination of Chlorogenic Acid in Nutraceuticals Using Voltammetric Sensors Based on Screen-Printed Carbon Electrode Modified with Graphene and Gold Nanoparticles

2021 ◽  
Vol 22 (16) ◽  
pp. 8897
Author(s):  
Irina-Georgiana Munteanu ◽  
Constantin Apetrei
Keyword(s):  
Gold Nanoparticles ◽  
Cyclic Voltammetry ◽  
Chlorogenic Acid ◽  
Electrochemical Determination ◽  
Point Of View ◽  
Spectrometric Method ◽  
Statistical Point ◽  
Voltammetric Sensors ◽  
Screen Printed

The present study describes the electrochemical properties of three screen-printed electrodes (SPEs), the first electrode being carbon-based (C), the second graphene-based (GPH), and the third based on GPH modified with gold nanoparticles (GNP). These electrodes were used for the study of the electrochemical behavior of chlorogenic acid in different aqueous solutions, at pH = 7. In chlorogenic acid solution, a redox process was noticed in the case of all three electrodes; GPH and GNP significantly improved the sensor response regarding sensitivity and reversibility, a fact demonstrated by characterizing the sensor by cyclic voltammetry in potassium ferrocyanide, which corresponds to the exchange of two electrons and two protons. Moreover, the calibration curves for each sensor were developed, subsequently calculating the detection limits (LOD) and the quantification limits (LOQ). Low LOD and LOQ were obtained, the best—of the order of 10−7 M (LOD = 0.62 × 10−7 M; LOQ = 1.97 × 10−7 M)—being obtained in the case of GPH-GNP-SPE, which demonstrates that the method may be applied for determining chlorogenic acid in real samples. Thus, the sensors were successfully used for the quantitative determination of chlorogenic acid in three nutraceutical products. The validation of the results was done using the FTIR method. The results obtained by cyclic voltammetry were in accordance with those obtained by the spectrometric method, without significant differences from a statistical point of view.

Electrochemical Determination of Inorganic Phosphate

2011 ◽  
Vol 339 ◽  
pp. 435-439 ◽  
Author(s):  
Wen Juan Zheng ◽  
Hai Tao Zheng ◽  
Yan Ling Li ◽  
Xing Sheng Wang ◽  
Shin Ichiro Suye
Keyword(s):  
Cyclic Voltammetry ◽  
Detection Limit ◽  
Electrode Surface ◽  
Inorganic Phosphate ◽  
Differential Pulse ◽  
Electrochemical Determination ◽  
Sensor Response ◽  
Pulse Voltammetry ◽  
Phosphate Sensor

An electrochemical phosphate sensor based on the precipitation of molybdophosphate on electrode surface was developed for the determination of inorganic phosphate. The condition for the formation of the molybdophosphate was studied and cyclic voltammetry and differential pulse voltammetry were utilized for the determination. A detection limit of 10 ppm was obtained and the sensor response was approximate liner in the range between 10-100 ppm.

scholarly journals Exploitation of Enzymes for the Production of Biofuels: Electrochemical Determination of Kinetic Parameters of LPMOs

2021 ◽  
Vol 11 (11) ◽  
pp. 4715
Author(s):  
Dimitrios Zouraris ◽  
Anthi Karnaouri ◽  
Raphaela Xydou ◽  
Evangelos Topakas ◽  
Antonis Karantonis
Keyword(s):  
Kinetic Parameters ◽  
Filamentous Fungus ◽  
Electrode Surface ◽  
Plant Biomass ◽  
Electrochemical Determination ◽  
Redox Enzymes ◽  
Electrode Surfaces ◽  
Lytic Polysaccharide Monooxygenases ◽  
Polysaccharide Monooxygenases

Lytic polysaccharide monooxygenases (LPMOs) consist of a class of enzymes that boost the release of oxidised products from plant biomass, in an approach that is more eco-friendly than the traditional ones, employing harsh chemicals. Since LPMOs are redox enzymes, they could possibly be exploited by immobilisation on electrode surfaces. Such an approach requires knowledge of kinetic and thermodynamic information for the interaction of the enzyme with the electrode surface. In this work, a novel methodology is applied for the determination of such parameters for an LPMO from the filamentous fungus Thermothelomyces thermophila, MtLPMO9H.

scholarly journals Simultaneous and selective electrochemical determination of hydroquinone, catechol and resorcinol at poly(1,5-diaminonaphthalene)/glassy carbon-modified electrode in different media

RSC Advances ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 6346-6355 ◽  
Author(s):  
Khalid Mahmoud Hassan ◽  
Abla Ahmed Hathoot ◽  
Mohamed Fathi Abo oura ◽  
Magdi Abdel Azzem
Keyword(s):  
Cyclic Voltammetry ◽  
Modified Electrode ◽  
Glassy Carbon ◽  
Square Wave Voltammetry ◽  
Electrochemical Determination ◽  
Electrochemical Behaviors ◽  
Square Wave ◽  
Wave Voltammetry ◽  
Glassy Carbon Modified Electrode

Electrochemical behaviors of hydroquinone, catechol and resorcinol were examined at poly(1,5-diaminonaphthalene)/glassy carbon-modified electrode by cyclic voltammetry, square wave voltammetry and chronoamperometry techniques in different media.

scholarly journals Development and Characterization of an Electroless Plated Silver/Cysteine Sensor Platform for the Electrochemical Determination of Aflatoxin B1

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Alex Paul Wacoo ◽  
Mathew Ocheng ◽  
Deborah Wendiro ◽  
Peter California Vuzi ◽  
Joseph F. Hawumba
Keyword(s):  
Cyclic Voltammetry ◽  
Horseradish Peroxidase ◽  
Electroless Deposition ◽  
Limit Of Detection ◽  
Electrochemical Determination ◽  
Sensor Platform ◽  
Ft Ir ◽  
Aflatoxin B

An electroless plated silver/cysteine sensor platform [Glass|silver|cysteine|aflatoxin B1|horseradish peroxidase] for the Electrochemical detection of aflatoxin B1was developed and characterized. This involved four major steps: (1) an electroless deposition of silver (plating) onto a glass slide, (2) immobilization of cysteine; (3) conjugation of aflatoxin B1to cysteine groups; and (4) blocking of free cysteine groups with horseradish peroxidase (HRP). The binding of cysteine to the silver was demonstrated by the disappearance of thiol (S-H) groups at 2500 cm−1using Fourier transmittance infrared spectra (FT-IR), while the subsequent steps in the assembly of sensor platform were monitored using both FT-IR and cyclic voltammetry, respectively. The sensor platform exhibited a broadened nonsymmetrical redox couple as indicated by cyclic voltammetry. The platform was further characterized for sensitivity and limit of detection. The indirect competitive immunoassay format, whereby free and immobilized aflatoxin B1on the sensor competed for the binding site of free anti-aflatoxin B1antibody, was used at various concentrations of aflatoxin B1. The sensor generated differential staircase voltammogram that was inversely proportional to the concentration of aflatoxin B1and aflatoxin B1in the range of 0.06–1.1 ng/mL with a detection limit of 0.08 ng/mL could be detected.

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