Electrochemical Response of Gold Nanoparticles at a Graphite Electrode

2014 ◽  
Vol 1040 ◽  
pp. 297-302 ◽  
Author(s):  
D.O. Perevezentseva ◽  
E.V. Gorchakov
Keyword(s):  
Gold Nanoparticles ◽  
Cyclic Voltammetry ◽  
Electrochemical Oxidation ◽  
Phase Structure ◽  
Graphite Electrode ◽  
Supporting Electrolyte ◽  
Potential Range ◽  
Cyclic Voltammogram ◽  
Cathodic Peak ◽  
Graphite Electrodes

The electrochemical activity of gold nanoparticles at graphite electrodes by the method of cyclic voltammetry is studied. In this article the nature of the supporting electrolyte, modification time of graphite electrode by gold nanoparticles and the potential range on the value of the “inverse” cathodic peak are investigated. The “inverse” cathodic peak of gold nanoparticles formed in the reaction mixture HAuCl4:Na3C6H5O7:NaBH4=1:1:4 is observed on the cathodic branch of cyclic voltamperegram at Ec = 0.05 V at graphite electrode. The mechanism of stepwise electrochemical oxidation and reduction of the phase structure of gold on the surface of the graphite electrode in 0.1 M NaOH is offered. The “inverse” cathodic peak of gold nanoparticles on the cathodic branch of cyclic voltammogram at graphite electrode is caused by oxidation of Au2O to Au2O3.<br /><br />

scholarly journals Exploration of Electrochemical Intermediates of the Anticancer Drug Doxorubicin Hydrochloride Using Cyclic Voltammetry and Simulation Studies with an Evaluation for Its Interaction with DNA

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Partha Sarathi Guin ◽  
Saurabh Das
Keyword(s):  
Cyclic Voltammetry ◽  
Anticancer Drug ◽  
Dna Interaction ◽  
Calf Thymus Dna ◽  
Potential Range ◽  
Spectroscopic Techniques ◽  
Doxorubicin Hydrochloride ◽  
Cathodic Peak ◽  
Peak Current ◽  
Calf Thymus

Electrochemical behavior of the anticancer drug doxorubicin hydrochloride was studied using cyclic voltammetry in aqueous medium using Hepes buffer (pH~7.4). At this pH, doxorubicin hydrochloride undergoes a reversible two-electron reduction withE1/2value −665±5 mV (versus Ag/AgCl, saturated KCl). Depending on scan rates, processes were either quasireversible (at low scan rates) or near perfect reversible (at high scan rates). This difference in behavior of doxorubicin hydrochloride with scan rate studied over the same potential range speaks of differences in electron transfer processes in doxorubicin hydrochloride. Attempt was made to identify and understand the species involved using simulation. The information obtained was used to study the interaction of doxorubicin hydrochloride with calf thymus DNA. Cathodic peak current gradually decreased as more calf thymus DNA was added. The decrease in cathodic peak current was used to estimate the interaction of the drug with calf thymus DNA. Nonlinear curve fit analysis was applied to evaluate the intrinsic binding constant and site size of interaction that was compared with previous results on doxorubicin hydrochloride-DNA interaction monitored by cyclic voltammetry or spectroscopic techniques.

Electrochemical dissolution of chalcopyrite studied by voltammetry of immobilized microparticles

2006 ◽  
Vol 60 (4) ◽  
Author(s):  
L’. Pikna ◽  
L. Lux ◽  
T. Grygar
Keyword(s):  
Cyclic Voltammetry ◽  
Sodium Chloride ◽  
Hydrochloric Acid ◽  
Acid Solution ◽  
Graphite Electrode ◽  
Potential Range ◽  
Electrochemical Dissolution ◽  
Reaction Products ◽  
Anodic Reaction ◽  
Hydrochloric Acid Medium

AbstractThe characteristics of anodic electrochemical dissolution of chalcopyrite (CuFeS2) powder in hydrochloric acid medium with sodium chloride have been studied. Cyclic voltammetry and chronopotentiometry of immobilized microparticles using paraffin-impregnated graphite electrode was employed. Present work is focused on electrochemical identification of chalcopyrite cathodic and anodic reaction products within the potential range of −0.7 to +0.8 V (vs. SCE) in hydrochloric acid solution containing sodium chloride and/or copper(II) chloride.

scholarly journals Electrocoating Polypyrrole on Gold-Wire Electrode as Potential Mediator Membrane Candidate for Anionic Surfactant Electrode Sensor

2020 ◽  
Vol 23 (5) ◽  
pp. 167-176
Author(s):  
Abdul Haris Watoni ◽  
Indra Noviandri ◽  
Muhammad Nurdin ◽  
La Ode Ahmad Nur Ramadhan
Keyword(s):  
Cyclic Voltammetry ◽  
Conducting Polymer ◽  
Limit Of Detection ◽  
Supporting Electrolyte ◽  
Sodium Dodecyl ◽  
Gold Wire ◽  
Potential Range ◽  
Wire Electrode ◽  
Potential Response ◽  
Potential Mediator

The development of polypyrrole as a potential mediator membrane candidate for sodium dodecyl sulfate (SDS) sensor electrode has been investigated. The polypyrrole membrane was synthesized electrochemically from the pyrrole and coated at the surface of a 1.0 mm diameter of the gold-wire electrode. Electropolymerization of pyrrole and coating of the polypyrrole produced was performed by cyclic voltammetry technique in the electrochemical cell containing supporting electrolyte of 0.01 M NaClO4 with an optimum potential range of -0.9 V–1.0 V, the scanning rate of 100 mV/s, an electric current of 2 mA, and running of potential scanning of 10 cycles. By using the similar optimal parameters of cyclic voltammetry, electropolymerization of 0.01 M pyrrole solution containing 0.001 M SDS also produces a polypyrrole membrane coated at the gold-wire electrode surface. These coated electrodes have the potential response-ability toward DS- anions in the concentration range of 10-7 M–10-5 M with a limit of detection of 10-7 M and sensitivity of electrode of 9.9 mV/decade. This finding shows that the SDS solution’s role is as supporting electrolyte and also as a source of DS- dopant during the pyrrole electropolymerization processes. Dopants are trapped in the polymer membrane during the electrochemical formation of polypyrrole and role as ionophores for DS- anion in the analyte solution. A potential response to the electrode phenomena is excellent basic scientific information for further synthesis of conducting polymer and development of conducting polymer-coated wire electrode model, especially in the construction of ion-selective electrode (ISE) for the determination of anionic surfactants with those models.

scholarly journals Monitoring biofilm formation by using cyclic voltammetry - effect of the experimental conditions on biofilm removal and activity

2003 ◽  
Vol 47 (5) ◽  
pp. 51-56 ◽  
Author(s):  
M.S. Gião ◽  
M.I. Montenegro ◽  
M.J. Vieira
Keyword(s):  
Cyclic Voltammetry ◽  
Sweep Rate ◽  
Epifluorescence Microscopy ◽  
Potential Range ◽  
Strong Impact ◽  
Cyclic Voltammogram ◽  
Platinum Electrodes ◽  
Platinum Surface ◽  
Experimental Conditions ◽  
Biofilm Removal

The effect of experimental conditions on cyclic voltammetry experiments on platinum electrodes covered with biofilms formed by Pseudomonas fluorescens for 2 hours was investigated. Results show that recycling the potential stabilizes the shape of the cyclic voltammogram after 135 cycles, but the observation of the electrodes by epifluorescence microscopy showed that cells are still adhered to the platinum surface. Some experimental conditions were changed during the electrochemical measurements - sweep rate, pH of the buffer and applied potential range. Some of these parameters had a strong impact on the bacteria that are adhered to the surface, increasing the death and removal in some circumstances.

scholarly journals The Degradation of Deoxynivalenol by Using Electrochemical Oxidation with Graphite Electrodes and the Toxicity Assessment of Degradation Products

Toxins ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 478 ◽  
Author(s):  
Suli Xiong ◽  
Xiao Li ◽  
Changsong Zhao ◽  
Jingqi Gao ◽  
Wenjuan Yuan ◽  
...  
Keyword(s):  
Electrochemical Oxidation ◽  
Degradation Rate ◽  
Graphite Electrode ◽  
Degradation Products ◽  
Supporting Electrolyte ◽  
Degradation Process ◽  
Treated Group ◽  
Cell Counting ◽  
Epithelial Cell Line ◽  
Dapi Staining

Deoxynivalenol (DON) is a common mycotoxin, which is known to be extremely harmful to human and livestock health. In this study, DON was degraded by electrochemical oxidation (ECO) using a graphite electrode and NaCl as the supporting electrolyte. The graphite electrode is advantageous due to its electrocatalytic activity, reusability, and security. The degradation process can be expressed by first-order kinetics. Approximately 86.4% of DON can be degraded within 30 min at a potential of 0.5 V. The degradation rate reached 93.2% within 30 min, when 0.5 V potential was used for electrocatalyzing a 10 mg/L DON solution. The degradation rate of DON in contaminated wet distiller’s grain with solubles (WDGS) was 86.37% in 60 min. Moreover, results from the cell counting kit-8 (CCK-8) and 4,6-diamidino-2-phenylindole dihydrochloride (DAPI) staining assay indicated that ECO reduced the DON-induced cytotoxicity and apoptotic bodies in a gastric epithelial cell line (GES-1) compared to the DON-treated group. These findings provide new insights into the application of ECO techniques for degrading mycotoxins, preventing food contamination, and assessing DON-related hazards.

Preparation of polypyrrole by direct electrochemical oxidation of pyrrole on paraffin impregnated graphite electrode

2011 ◽  
Vol 76 (12) ◽  
pp. 1931-1954
Author(s):  
Mária Filkusová ◽  
Renáta Oriňáková ◽  
Kvetoslava Markušová ◽  
Karol Kovaľ
Keyword(s):  
Cyclic Voltammetry ◽  
Electron Microscope ◽  
Electrochemical Oxidation ◽  
Ph Value ◽  
Graphite Electrode ◽  
Monomer Concentration ◽  
Scan Rate ◽  
Electrochemical Polymerisation ◽  
Scanning Electron

The formation of polypyrrole (PPy) layers by electrochemical polymerisation of pyrrole (Py) on paraffin impregnated graphite electrode (PIGE) was studied. Electrochemical oxidation of Py was studied by means of cyclic voltammetry (CV) and the morphology of the deposited layers was investigated with scanning electron microscope (SEM). The structure and quality of PPy layers on PIGE depends on monomer concentration, pH value, stirring intensity and scan rate during the polymerisation process.

Electrochemical Oxidation of Borohydride on Cu Electrode

2011 ◽  
Vol 347-353 ◽  
pp. 3264-3267 ◽  
Author(s):  
Dong Hong Duan ◽  
Yi Fang Zhao ◽  
Shi Bin Liu ◽  
Ai Lian Wu
Keyword(s):  
Cyclic Voltammetry ◽  
Electrochemical Oxidation ◽  
Electrochemical Behavior ◽  
Intermediate Product ◽  
Electrode Materials ◽  
Oxidation Process ◽  
Potential Range ◽  
Direct Oxidation ◽  
Catalytic Activities ◽  
Electro Oxidation

The electrochemical behavior of BH4- on Cu electrode in 1M NaOH was investigated by cyclic voltammetry(CV) in the potential range of -1.2V to 0.4V versus Hg/HgO. The CV results show that Cu electrode has obvious catalytic activities to the BH4- hydrolysis which belongs to ‘catalytic’ electrode materials. The BH4- electro-oxidation process on Cu is complex and it could associate with the BH4- hydrolysis reaction, followed by oxidation of the intermediate H, then, the intermediate product (e.g. BH3OH−) oxidized, and direct oxidation of BH4- at more positive potentials.

Electrochemical Activity of Methionine at Graphite Electrode Modified with Gold Nanoparticles

2016 ◽  
Vol 685 ◽  
pp. 563-568 ◽  
Author(s):  
D.O. Perevezentseva ◽  
K.V. Skirdin ◽  
E.V. Gorchakov ◽  
V.I. Bimatov
Keyword(s):  
Gold Nanoparticles ◽  
Graphite Electrode ◽  
Electrochemical Activity ◽  
Molar Ratio ◽  
Determination Limit ◽  
Methionine Oxidation ◽  
Toxic Substances ◽  
Cathodic Peak ◽  
Accumulation Time

The “inverse” cathodic peak of gold nanoparticles is observed in the reaction mixture used to obtain gold nanoparticles HAuCl4:Na3C6H5O7:NaBH4=125:8:1 and accumulation time is 90 s. The conditions in which methionine has the greatest electrochemical activity were determined. They are as follows: the molar ratio of reagents HAuCl4:Na3C6H5O7:NaBH4=125:8:1 and accumulation time is 90 s, 0.1 M NaOH. The mechanism of methionine oxidation is proposed to be on the surface of the graphite electrode modified with gold nanoparticles in 0.1 M NaOH. The determination limit of methionine is 0.7 •10-14 M. The proposed method is simple, sensitive, and does not need toxic substances.

scholarly journals Electrochemical Studies of o- and p- Anisidine

2015 ◽  
Vol 3 (2) ◽  
pp. 267-271
Author(s):  
Richa Sharma ◽  
Sushma Dave
Keyword(s):  
Cyclic Voltammetry ◽  
Electrochemical Oxidation ◽  
Platinum Electrode ◽  
Linear Sweep Voltammetry ◽  
Electrochemical Studies ◽  
Oxidation Peak ◽  
Cathodic Peak ◽  
Linear Sweep ◽  
And Diffusion ◽  
Sensitive Method

Electrochemical oxidation of methyl substituted aniline (anisidine) has been done on both gold and platinum electrode using cyclic voltammetry. The results were compared in different supporting electrolytes such as KCl, KNO3, H2SO4, HCl. Effect of pH was observed on electrochemical oxidation of o- & p- anisidine at gold and platinum electrode. During various scan single oxidation peak during first forward scan with no corresponding cathodic peak was obtained while a new anodic cathodic couple peak appears in subsequent scan obtained. Kinetic parameters like heterogeneous rate constant, transfer co-efficient and diffusion co-efficient were also calculated. A sensitive method was developed for estimation of micro quantities of anisidine by linear sweep voltammetry and hydrodynamic voltammetry.Int J Appl Sci Biotechnol, Vol 3(2): 267-271 DOI: http://dx.doi.org/10.3126/ijasbt.v3i2.12615 

Electrochemical Properties Test of Vanadium Electrolyte Containing V (III) and V (IV) Ion

2014 ◽  
Vol 809-810 ◽  
pp. 822-830 ◽  
Author(s):  
Wei Zao Liu ◽  
Dong Mei Luo ◽  
Dan Li ◽  
Xiao Ling Meng ◽  
Fan Bo Zeng
Keyword(s):  
Cyclic Voltammetry ◽  
Current Density ◽  
Redox Reaction ◽  
Graphite Electrode ◽  
Electrochemical Activity ◽  
Cathodic Peak ◽  
Peak Current Density ◽  
Vanadium Concentration ◽  
Peak Current ◽  
Anodic Peak Current

The electrochemical behavior of vanadium solution containing V (III) and V (IV) ion each 50% was characterized by cyclic voltammetry and chronopotentiometry with different working electrodes, temperatures, H2SO4concentrations and vanadium ion concentrations. Cyclic voltammetry analysis indicated that V(IV)/V(V) redox reaction at graphite electrode showed good electrochemical activity and reversibility while V(III)/V(II) redox reaction showed bad electrochemical activity and reversibility on Pt, glassy-carbon and graphite electrode. The cathodic peak current density of V(III)/V(II) couples increased first then remained almost unchanged as temperature raised and approached a maximum at 60°C. With H2SO4concentration elevated, the electrolyte became viscous and diffusion step was the controlling step. The electrochemical activity of electrolyte increased with ascending vanadium concentration, so did the reversibility of V(IV)/V(V) couples. However, no matter what vanadium concentration was, the reversibility of V(III)/V(II) couples stayed poor. Stirring in solution benefited to the anodic peak current density of V(IV)/V(V) couples whereas it did not to the cathodic peak current density of V(III)/V(II) couples. The diffusion coefficients of V(III),V(IV) were calculated as 1.17×10-5,0.919×10-5cm2·s-1, respectively. Chronopotentiometry test indicated that solution as anolyte showed good charging performance while solution as catholyte showed poor charging performance.

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