scholarly journals Fabrication and characterization of molybdenum(VI)complex-TiO2 nanoparticles modified electrode for the electrocatalytic determination of L-cysteine

2011 ◽  
Vol 76 (4) ◽  
pp. 575-589 ◽  
Author(s):  
Mohammad Mazloum-Ardakani ◽  
Hadi Beitollahi ◽  
Zahra Taleat ◽  
Masoud Salavati-Niasari
Keyword(s):  
Cyclic Voltammetry ◽  
Tio2 Nanoparticles ◽  
Signal To Noise Ratio ◽  
Carbon Paste ◽  
Good Electrocatalytic Activity ◽  
Electron Transfer Rate Constant ◽  
Charge Transfer Coefficient ◽  
Electrocatalytic Determination

A novel voltammetric sensor for the determination of L-cysteine (L-Cys) was fabricated based on a TiO2 nanoparticles/bis [bis(salicylidene-1,4-phenylenediamine)-molybdenum(VI)] carbon paste electrode. The electrochemical behavior of the sensor was investigated in detail by cyclic voltammetry. The apparent electron transfer rate constant (ks) and charge transfer coefficient (?) of the TiO2 nanoparticles / molybdenum(VI) complex/CPE were also determined by cyclic voltammetry and found to be about 4.53 s?1 and 0.54, respectively. The sensor displayed good electrocatalytic activity towards the oxidation of LCys. The peak potential for the oxidation of L-Cys was lowered by at least 130 mV compared with that obtained at an unmodified CPE. Under optimal conditions, the linear range spans L-Cys concentrations from 1.5?10?6 M to 1.2?10?3 M and the detection limit was 0.70 ? 0.01 ?M at a signal-to-noise ratio of 2. In addition, the sensor showed good stability and reproducibility.

scholarly journals A new electrochemical sensor based on carbon paste electrode/Ru(III) complex for determination of nitrite: Electrochemical impedance and cyclic voltammetry measurements

Measurement ◽  
2016 ◽  
Vol 92 ◽  
pp. 524-533 ◽  
Author(s):  
Achour Terbouche ◽  
Siham Lameche ◽  
Chafia Ait-Ramdane-Terbouche ◽  
Djamila Guerniche ◽  
Djahida Lerari ◽  
...  
Keyword(s):  
Cyclic Voltammetry ◽  
Electrochemical Sensor ◽  
Carbon Paste Electrode ◽  
Electrochemical Impedance ◽  
Carbon Paste ◽  
Paste Electrode

scholarly journals Electrocatalytic determination of captopril using a carbon paste electrode modified with N-(ferrocenyl methylidene) fluorene-2-amine and graphene/ZnO nanocomposite

2019 ◽  
Vol 84 (2) ◽  
pp. 175-185 ◽  
Author(s):  
Mohadeseh Safaei ◽  
Hadi Beitollahi ◽  
Masoud Shishehbore ◽  
Somayeh Tajik ◽  
Rahman Hosseinzadeh
Keyword(s):  
Modified Electrode ◽  
Carbon Paste Electrode ◽  
Electrocatalytic Oxidation ◽  
Differential Pulse ◽  
Diagnostic Techniques ◽  
Carbon Paste ◽  
Pulse Voltammetry ◽  
Electrocatalytic Determination ◽  
Paste Electrode

A carbon paste electrode (CPE) was modified with N-(ferrocenylmethylidene) fluorene-2-amine and graphene/ZnO nanocomposite. The electrooxidation of captopril (CAP) at the surface of the modified electrode was studied using electrochemical approaches. The electrochemical study of the modified electrode, as well as its efficiency for the electrocatalytic oxidation of captopril, is described. The electrode was used to study the electrocatalytic oxidation of captopril, by cyclic voltammetry (CV), chronoamperometry (CHA) and differential pulse voltammetry (DPV) as diagnostic techniques. It has been found that the oxidation of captopril at the surface of modified electrode occurs at a potential of about 340 mV less positive than that of an unmodified CPE. DPV of captopril at the electrochemical sensor exhibited two linear dynamic ranges (0.1?100.0 and 100.0?800.0 ?M) with a detection limit (3?) of 0.05 ?M.

scholarly journals Characterization of graphite-epoxy composite electrodes for free electrochemical detection of adenine and guanine in DNA

2021 ◽  
Author(s):  
Abel Ibrahim Balbin Tamayo ◽  
Leodanis Correa Fajardo ◽  
Ana Margarita Esteva Guas
Keyword(s):  
Square Wave Voltammetry ◽  
Construction Materials ◽  
Composite Electrodes ◽  
Single Chain ◽  
Electron Transfer Rate ◽  
Redox Probe ◽  
Wave Voltammetry ◽  
Electron Transfer Rate Constant

Graphite-epoxy composites (GECs) are alternative construction materials for electro­chemical sensors. For these materials, the electron transfer rate constant of some redox reaction depends additionally on the stoichiometric relationship between the insulating and conducting phases of the composite. In this work, the influence of dif­fe­rent ratios of araldite/hardener/graphite on the electrochemical properties of GEC electrodes is evaluated for the simultaneous determination of adenine and guanine in the single chain DNA, using the square wave voltammetry technique. Six GEC electro­des were prepared with different ratios of components, and electrochemically charac­terized by cyclic voltammetry in the presence of ferri/ferrocyanide redox couple as a redox probe. GEC electrodes that showed the best electrochemical responses of redox probe were characterized by thermogravimetric analysis (TGA) and used for the simul­taneous determination of free adenine and guanine in a solution, and DNA oligonu­cle­otides. The best results were obtained for GEC electrodes containing twice higher volu­me of araldite resin with respect to the hardener. TGA analysis revealed presence of 15-26 % of resin for these GEC electrodes. The obtained results revealed potential appl­ication of these GEC electrodes as DNA sensors based on the oxidation signal of guanine.

Fast and selective determination of phenazopyridine at a novel multi-walled carbon nanotube modified ZnCrFeO4 magnetic nanoparticle paste electrode

RSC Advances ◽  
2015 ◽  
Vol 5 (47) ◽  
pp. 37431-37439 ◽  
Author(s):  
M. Taei ◽  
F. Hasanpour ◽  
M. Movahedi ◽  
Sh. Mohammadian
Keyword(s):  
Carbon Nanotube ◽  
Carbon Paste Electrode ◽  
Magnetic Nanoparticle ◽  
Modified Carbon Paste Electrode ◽  
Carbon Paste ◽  
Selective Determination ◽  
Multi Walled Carbon Nanotube ◽  
Electrocatalytic Determination ◽  
Paste Electrode

Fabrication process of MWCNTs/ZnCrFeO4 modified carbon paste electrode for electrocatalytic determination of phenazopyridine at the surface (a) CPE, and (b) MWCNTs/ZnCrFeO4 modified carbon paste electrode.

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