scholarly journals Carbon nanotube-ionic liquid nanocomposite modified carbon-ceramic electrode for determination of dopamine in real samples

2013 ◽  
Vol 11 (7) ◽  
pp. 1172-1186 ◽  
Author(s):  
Mir Majidi ◽  
Reza Baj ◽  
Abdolhossein Naseri
Keyword(s):  
Ionic Liquid ◽  
Carbon Nanotube ◽  
Modified Electrode ◽  
Electrochemical Impedance ◽  
Differential Pulse ◽  
Selective Determination ◽  
Carbon Ceramic Electrode ◽  
Electro Oxidation ◽  
Carbon Ceramic

AbstractRoom temperature 1-butyl-3-methylimidazolium tetraflouroborate ([BMIM][BF4]) ionic liquid was employed for dispersion of multi walled carbon nanotubes (MWCNTs) and the formation of nanocomposite on the surface of a carbon-ceramic electrode. The surface of the modified electrode was characterized using scanning electron microscopy and electrochemical impedance spectroscopy. The modified electrode exhibited excellent electrochemical activity to oxidation of dopamine (DA); whereas electro oxidation of ascorbic acid (AA) was not seen and electro oxidation of uric acid (UA) appeared at a more positive potential than DA. The multi walled carbon nanotube-ionic liquid nanocomposite modified carbon-ceramic electrode was used for the selective determination of DA in the presence of high levels of AA and UA using differential pulse voltammetry. The calibration curve for DA was linear in the range of 3.00 to 130 µM with the detection limit (S/N=3) of 0.87 µM. The present electrode was successfully applied to the determination of DA in some commercial pharmaceutical samples and human blood serum.

scholarly journals Carbon ceramic electrode incorporated with zeolite ZSM-5 for determination of Piroxicam

2010 ◽  
Vol 8 (1) ◽  
pp. 155-162 ◽  
Author(s):  
Karim Asadpour-Zeynali ◽  
Mir Majidi ◽  
Mitra Zarifi
Keyword(s):  
Modified Electrode ◽  
Pharmaceutical Formulations ◽  
Differential Pulse ◽  
Solution Ph ◽  
Carbon Ceramic Electrode ◽  
Experimental Parameters ◽  
Voltammetric Behavior ◽  
Carbon Ceramic ◽  
Optimized Conditions

AbstractA new chemically modified electrode is constructed based on carbon ceramic electrode incorporated with zeolite ZSM-5. Voltammetric behavior of piroxicam at the carbon ceramic zeolite modified electrode (CCZME) was investigated. The modified electrode exhibited catalytic activity toward the electrooxidation of piroxicam. Experimental parameters such as solution pH, scan rate, concentration of piroxicam and zeolite amount were studied. It has been shown that using the CCZME, piroxicam can be determined by differential pulse voltammetry (DPV) and hydrodynamic amperometry (HA). Under the optimized conditions the calibration plots are linear in the concentration ranges of 0.20–25.00 and 0.20–50.10 μM with limit of detections of 0.65 and 0.29 μM for DPV and HA, respectively. The modified electrode with DPV and HA methods was successfully applied for analysis of piroxicam in pharmaceutical formulations. The results were favorably compared to those obtained by the spiked method. The results of the analysis suggest that the proposed method has promise for the routine determination of piroxicam in the products examined.

Electrochemical Behavior and Voltammetric Determination of Losartan Using Carbon Ceramic Electrode Modified with Room Temperature Ionic Liquid

2020 ◽  
Vol 18 (4) ◽  
pp. 322-327
Author(s):  
Mahzad Firouzi ◽  
Masoud Giahi ◽  
Mostafa Najafi ◽  
Seyed Saied Homami ◽  
Seyed Husain Hashemi Mousavi
Keyword(s):  
Ionic Liquid ◽  
Room Temperature ◽  
Dynamic Range ◽  
Electrochemical Impedance ◽  
Linear Sweep Voltammetry ◽  
Pharmaceutical Formulations ◽  
Room Temperature Ionic Liquid ◽  
Carbon Ceramic Electrode ◽  
Carbon Ceramic

Herein, an electrochemical sensor has been proposed for the determination of losartan (LOS) in pharmaceutical formulations. A room temperature ionic liquid, 1-butyl-3-methylimidazolium hexafluorophosphate (BMIM.PF6) was applied to fabricate a modified carbon ceramic electrode (IL-CCE). The electrochemical studies were performed by the cyclic and linear sweep voltammetry (CV and LSV), chronoamperometry and electrochemical impedance spectroscopy (EIS) techniques. The anodic peak currents were increased with the LOS concentration and indicated a linear dynamic range from 20 to 200 μM and a detection limit of 11.7 μM (S/N = 3) under the optimized conditions. Satisfactory results were obtained by analysis of LOS in pharmaceutical tablets.

scholarly journals Rapid Electrochemical Monitoring of Tyrosine by Poly (Riboflavin) Modified Carbon Nanotube Paste Electrode as a Sensitive Sensor and its Applications in Pharmaceutical Samples

2021 ◽  
Vol 11 (6) ◽  
pp. 14661-14672
Keyword(s):  
Carbon Nanotube ◽  
Differential Pulse ◽  
Pharmaceutical Samples ◽  
Electrocatalytic Effect ◽  
Carbon Nanotube Paste Electrode ◽  
Sensitive Sensor ◽  
Electro Oxidation ◽  
Electrochemical Monitoring ◽  
Paste Electrode

A poly(riboflavin) modified carbon nanotube paste electrode (PRFMCNTPE) is employed as a compatible and electrocatalytic sensor for the determination of Tyrosine (TYR). The analysis and assessment are carried out through differential pulse voltammetry (DPV) and Cyclic Voltammetry (CV). The surface of the intended sensor is examined through Field Emission Scanning Electron Microscopy (FE-SEM). The modified electrode shows the outstanding electrocatalytic effect for TYR with high selectivity and sensitivity as compared to carbon nanotube paste electrode (CNTPE). The electro-oxidation peak current of TYR and its concentration is found linear from 2 µM to 10 µM with a detection limit (LOD) of 0.45 µM. The developed sensor is productively applied for the determination of TYR in pharmaceutical samples like Tyrosine capsules. The adapted electrode shows good stability, excellent reproducibility, and remarkable sensitivity.

Encapsulation of hemin in Fe-based metal-organic frameworks and its application for the direct determination of aflatoxin M1

2021 ◽  
pp. 1-10
Author(s):  
F. Jahangiri-Dehaghani ◽  
H.R. Zare ◽  
Z. Shekari
Keyword(s):  
Electrochemical Impedance ◽  
Metal Organic Frameworks ◽  
Direct Determination ◽  
Differential Pulse ◽  
Aflatoxin M1 ◽  
Label Free ◽  
Electrochemical Aptasensor ◽  
Selective Determination ◽  
Metal Organic

A label-free electrochemical aptasensor was constructed for the sensitive and selective determination of AFM1. For preparation of the aptasensor, the AFM1 aptamer was immobilised on the surface of a glassy carbon electrode modified with hemin encapsulated in Fe-based metal-organic frameworks (hemin@Fe-MIL-101). The morphology and the structure of Fe-MIL-101 and hemin@Fe-MIL-101 were evaluated by scanning electron microscopy, Fourier-transform infrared spectroscopy, X-ray powder diffraction and Brunauer-Emmett-Teller-N2 sorption methods. Electrochemical impedance spectroscopy and cyclic voltammetry were performed to monitor the fabrication process of the electrochemical aptasensor. The electrochemical reduction current of hemin encapsulated in Fe-MIL-101 serves as a signal for the quantitative determination of AFM1. Differential pulse voltammetry was done to determine the AFM1 concentration in the linear range of 1.0×10-1-100.0 ng/ml. The detection limit of AFM1 was estimated to be 4.6×10-2 ng/ml. Finally, the fabricated aptasensor was applied to determine AFM1 in raw and boiled milk samples.

scholarly journals Highly Sensitive Detection of Dopamine at Ionic Liquid Functionalized RGO/ZIF-8 Nanocomposite-Modified Electrode

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Lei Cheng ◽  
Youjun Fan ◽  
Xingcan Shen ◽  
Hong Liang
Keyword(s):  
Ionic Liquid ◽  
Modified Electrode ◽  
Electrocatalytic Activity ◽  
Electrochemical Impedance ◽  
Modified Electrodes ◽  
Differential Pulse ◽  
Zeolitic Imidazolate Framework ◽  
Response Range ◽  
Highly Sensitive ◽  
Highly Sensitive Detection

A hybrid and hierarchical nanocomposite was successfully prepared by the growth of zeolitic imidazolate framework-8 (ZIF-8) on the template of ionic liquid (IL, [Bmim][BF4]) functionalized reduced graphene oxide (IL-RGO). The structure and morphology of the IL-RGO/ZIF-8 nanocomposite were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectrometer (FTIR), and Raman spectroscopy. The results showed that RGO sheets were refrained from restacking by IL, and ZIF-8 nanoparticles grew well on the surface of IL-RGO. Owing to the synergistic effect from large surface area and excellent electrocatalytic activity of ZIF-8 and great electrical conductivity of IL-RGO, a highly sensitive sensor for dopamine (DA) can be obtained. IL-RGO/ZIF-8-modified electrode exhibits good electrocatalytic activity and electroconductive properties towards DA which were investigated by cyclic voltammetry (CV), differential pulse voltammetry (DPV), and electrochemical impedance spectroscopy (EIS). Compared with bare or IL-RGO-modified electrodes, the IL-RGO/ZIF-8-modified electrode effectively depressed the oxidation overpotential of DA. The linear response range of DA was from 1.0×10−7 to 1.0×10−4 mol/L with a low detection of limit 3.5×10−8 mol/L. In addition, the sensor was shown to provide satisfactory stability for the determination of DA.

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