Electrocatalytic determination of maltol in food products by cyclic voltammetry with a poly(l-phenylalanine) modified electrode

2013 ◽  
Vol 5 (20) ◽  
pp. 5823 ◽  
Author(s):  
Xinying Ma ◽  
Mingyong Chao
2019 ◽  
Vol 84 (2) ◽  
pp. 175-185 ◽  
Author(s):  
Mohadeseh Safaei ◽  
Hadi Beitollahi ◽  
Masoud Shishehbore ◽  
Somayeh Tajik ◽  
Rahman Hosseinzadeh

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.


2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Koh Sing Ngai ◽  
Wee Tee Tan ◽  
Zulkarnain Zainal ◽  
Ruzniza Mohd Zawawi ◽  
Joon Ching Juan

A rapid, simple, and sensitive method for the electrochemical determination of paracetamol was developed. A single-walled carbon nanotube/nickel (SWCNT/Ni) nanocomposite was prepared and immobilized on a glassy carbon electrode (GCE) surface via mechanical attachment. This paper reports the voltammetry study on the effect of paracetamol concentration, scan rate, pH, and temperature at a SWCNT/Ni-modified electrode in the determination of paracetamol. The characterization of the SWCNT/Ni/GCE was performed by cyclic voltammetry. Variable pressure scanning electron microscopy (VPSEM) and energy dispersive X-ray (EDX) spectrometer were used to examine the surface morphology and elemental profile of the modified electrode, respectively. Cyclic voltammetry showed significant enhancement in peak current for the determination of paracetamol at the SWCNT/Ni-modified electrode. A linear calibration curve was obtained for the paracetamol concentration between 0.05 and 0.50 mM. The SWCNT/Ni/GCE displayed a sensitivity of 64 mA M−1and a detection limit of 1.17 × 10−7 M in paracetamol detection. The proposed electrode can be applied for the determination of paracetamol in real pharmaceutical samples with satisfactory performance. Results indicate that electrodes modified with SWCNT and nickel nanoparticles exhibit better electrocatalytic activity towards paracetamol.


Fuel ◽  
2012 ◽  
Vol 95 ◽  
pp. 15-18 ◽  
Author(s):  
Tina Rita Celli Zezza ◽  
Michelle de Souza Castilho ◽  
Nelson Ramos Stradiotto

2014 ◽  
Vol 6 (16) ◽  
pp. 6494-6503 ◽  
Author(s):  
Jiahong He ◽  
Ri Qiu ◽  
Wenpo Li ◽  
Shaohua Xing ◽  
Zhongrong Song ◽  
...  

By using cyclic voltammetry, eosin Y film was electrodeposited on the surface of glassy carbon electrode (GCE) to obtain the modified electrode (denoted as eosin Y/GCE).


2011 ◽  
Vol 76 (4) ◽  
pp. 575-589 ◽  
Author(s):  
Mohammad Mazloum-Ardakani ◽  
Hadi Beitollahi ◽  
Zahra Taleat ◽  
Masoud Salavati-Niasari

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.


Author(s):  
Ebrahim Zarei ◽  
Mohammad Reza Jamali ◽  
Farideh Ahmadi

In this study, ionic liquid 1-hexyl-3-methylimidazolium hexafluorophosphate was applied as additives to fabricate a novel ionic liquid/carbon nanotube paste electrode (IL/CNPE). This electrode was characterized by electrochemical impedance spectroscopy and cyclic voltammetry. Results showed that the electron transfer rate and reversibility of the electrode were increased by the ionic liquid. The morpho-logy of prepared IL/CNPE was studied by scanning electron microscopy. Nickel/ionic liquid modified carbon nanotube paste electrode (Ni/IL/CNPE) was also constructed by immersion of the IL/CNPE in nickel sulfate solution. Ionic liquid showed significant effect on the accumulation of nickel species on the surface of the electrode. Also, the values of electron transfer coefficient, charge-transfer rate constant and electrode surface coverage for Ni(II)/Ni(III) redox couple of the Ni/IL/CNPE were found to be 0.32 and 2.37×10-1 s-1 and 2.74×10-8 mol.cm-2, respectively. The Ni/IL/CNPE was applied successfully to highly efficient electrocatalytic oxidation of formaldehyde in alkaline medium. The effects of various factors on the efficiency of electrocatalytic oxidation of formaldehyde were optimized. Under the optimized condition, cyclic voltammetry of formaldehyde at the modified electrode exhibited two linear dynamic ranges in the concentration ranges of 7.00×10-6 to 9.60×10-5 mol.L-1 and 9.60×10-5 to 32.00×10-3 mol.L-1 with excellent detection limit of 9.50×10-7 mol.L-1 (3σ/slope), respectively. Also, the method was successfully applied for formaldehyde measurement in real sample. Copyright © 2018 BCREC Group. All rights reservedReceived: 11st March 2018; Revised:20th July 2018; Accepted: 28th July 2018How to Cite: Zarei, E., Jamali, M.R., Ahmadi, F. (2018). Highly Sensitive Electrocatalytic Determination of Formaldehyde Using a Ni/Ionic Liquid Modified Carbon Nanotube Paste Electrode. Bulletin of Chemical Reaction Engineering & Catalysis, 13 (3): 529-542 (doi:10.9767/bcrec.13.3.2341.529-542)Permalink/DOI: https://doi.org/10.9767/bcrec.13.3.2341.529-542 


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