scholarly journals Impedance aspect of charge storage at graphite and glassy carbon electrodes in potassium hexacyanoferrate (II) redox active electrolyte

2016 ◽  
Vol 6 (1) ◽  
pp. 37 ◽  
Author(s):  
Katja Magdić ◽  
Višnja Horvat-Radošević ◽  
Krešimir Kvastek
Keyword(s):  
Glassy Carbon ◽  
Redox Reaction ◽  
Supporting Electrolyte ◽  
Carbon Electrodes ◽  
Charge Storage ◽  
Potassium Hexacyanoferrate ◽  
Impedance Spectra ◽  
Glassy Carbon Electrodes ◽  
Redox Active ◽  
Diffusion Impedance

<p class="PaperAbstract"><span lang="EN-GB">Different types of charge storage mechanisms at unmodified graphite vs. glassy carbon electrodes in acid sulphate supporting solution containing potassium hexacyanoferrate (II) redox active electrolyte, have been revealed by electrochemical impedance spectroscopy and supported by cyclic voltammetry experiments. Reversible charge transfer of Fe(CN)6<sup>3-/4-</sup> redox reaction detected by assessment of CVs of glassy carbon electrode, is in impedance spectra indicated by presence of bulk diffusion impedance and constant double-layer/pseudocapacitive electrode impedance compared to that measured in the pure supporting electrolyte. Some surface retention of redox species detected by assessment of CVs of graphite electrode is in impedance spectra indicated by diffusion impedance coupled in this case by diminishing of double-layer/pseudo­capacitive impedance compared to that measured in the pure supporting electrolyte. This phenomenon is ascribed to contribution of additional pseudocapacitive impedance generated by redox reaction of species confined at the electrode surface.</span></p>

scholarly journals Determination of various insecticides and pharmaceuticals using differently modified glassy carbon electrodes

2007 ◽  
Vol 72 (12) ◽  
pp. 1465-1475 ◽  
Author(s):  
Ferenc Gaál ◽  
Valéria Guzsvány ◽  
Luka Bjelica
Keyword(s):  
Glassy Carbon ◽  
Supporting Electrolyte ◽  
Chloride Content ◽  
Chloride Anion ◽  
Carbon Electrodes ◽  
Glassy Carbon Electrodes ◽  
Surface Modified ◽  
Phosphorus Doped ◽  
Physiologically Active Compounds

The applicability of differently modified glassy carbon (GC) electrodes for direct or indirect determinations of various physiologically active compounds (insecticides and pharmaceuticals) in different formulations and some real samples was investigated. Samples of selected insecticides from the group of neonicotinoids with nitroguanidine (thiamethoxam and imidacloprid), cyanoimine (acetamiprid) and nitromethilene (nitenpyram) fragments, prepared in an appropriate manner, were determined by voltammetry on bare and surface-modified GC electrodes, while in the case of pharmaceuticals such as Trodon and Akineton, the chloride anion titration was followed using bare GC and phosphorus doped (P-GC) electrodes. The P-GC was also used to monitor the chloride content in the photocatalytic degradation of the (4-chloro-2-methylphenoxy)acetic acid herbicide. It was found that apart from the nature of the electrode material, the analyte and supporting electrolyte, as well as the pretreatment of the electrode surface essentially influences the applicability of the employed sensors.

Selective dopamine detection using aptamer-functionalized glassy carbon electrodes

2015 ◽  
Vol 93 (5) ◽  
pp. 572-577 ◽  
Author(s):  
Ryan Walsh ◽  
Uyen Ho ◽  
Xiao Li Wang ◽  
Maria C. DeRosa
Keyword(s):  
Ascorbic Acid ◽  
Electrochemical Detection ◽  
Glassy Carbon ◽  
Dna Aptamer ◽  
Carbon Electrodes ◽  
Glassy Carbon Electrodes ◽  
Organic Monolayer ◽  
Dopamine Detection ◽  
Redox Active ◽  
Viable Approach

The electrochemical detection of dopamine using glassy carbon electrodes suffers from a lack of selectivity toward the neurotransmitter, as interferences such as other catechol-containing neurochemicals and ascorbic acid can be oxidized at overlapping potentials. Several approaches have been employed to improve the selectivity of these electrodes towards dopamine including electrochemical pretreatment and organic monolayer depositions. Here, we characterize glassy carbon electrodes that were initially passivated through a trifluoromethylphenyl and nitrophenyl monolayer deposition and then functionalized with a specific DNA dopamine aptamer. Passivation with the mixed monolayer cuts off all signals from the redox-active neurochemicals. After functionalization with the DNA aptamer, the dopamine signal is restored and the electrodes are more responsive to dopamine than to any other related catechol-containing compounds or other common neurochemicals such as ascorbic acid. Our findings indicate that aptamer functionalization of glassy carbon electrodes may provide a viable approach for tuning the selectivity of electrochemical detection.

Anodic and cathodic modification of glassy-carbon electrodes affect iodine electrochemistry

2021 ◽  
Vol 379 ◽  
pp. 138181
Author(s):  
Shota Ito ◽  
Masatoshi Sugimasa ◽  
Yuichi Toshimitsu ◽  
Akihiro Orita ◽  
Masaki Kitagawa ◽  
...  
Keyword(s):  
Glassy Carbon ◽  
Carbon Electrodes ◽  
Glassy Carbon Electrodes

Ultrasensitive Electrochemical Determination of Phosphate in water by Hydrophilic TiO2 modified Glassy Carbon Electrodes

2021 ◽  
Author(s):  
Yan Jin ◽  
Tong QI ◽  
Yuqing Ge ◽  
Jin Chen ◽  
Li juan Liang ◽  
...  
Keyword(s):  
Differential Pulse Voltammetry ◽  
Glassy Carbon ◽  
Differential Pulse ◽  
Electrochemical Determination ◽  
Carbon Electrodes ◽  
Glassy Carbon Electrodes ◽  
Time Differential ◽  
Pulse Voltammetry ◽  
First Time

In this paper, ultrasensitive electrochemical determination of phosphate in water is achieved by hydrophilic TiO2 modified glassy carbon electrodes for the first time. Differential pulse voltammetry (DPV) method is proposed...

Sign in / Sign up

Export Citation Format

Share Document