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M H Pournaghiazar - One of the best experts on this subject based on the ideXlab platform.
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a carbon nanotube modified electrode for determination of caffeine by Differential Pulse Voltammetry
Chinese Journal of Catalysis, 2012Co-Authors: Biuck Habibi, Mehri Abazari, M H PournaghiazarAbstract:Abstract A simple and sensitive electrochemical detection of caffeine (CAF) using a single-walled carbon nanotubes on carbon-ceramic electrode (SWCNT/CCE) is reported. CAF was oxidized at the surface of the modified electrode to produce an anodic peak at 1.38 V versus the saturated calomel electrode in 0.01 mol/L, pH 1.7 H2SO4 solution in cyclic Voltammetry. The experimental parameters, namely, type of electrolyte, pH value, and amount of SWCNTs casted, were optimized. Using the optimum conditions, the anodic peak current in Differential Pulse Voltammetry was linear with CAF concentration in the range of 2.5 × 10−7–1.0 × 10−4 mol/L. The detection limit was 1.2 × 10−7 mol/L (S/N = 3). The modified electrode exhibited good stability and can be easily regenerated. The relative standard deviation of the peak current obtained for a 5.0 × 10−5 mol/L CAF solution was 3.0%. The influence of some important biological compounds, namely, ascorbic acid, dopamine, and uric acid and addictive compounds like codeine, morphine, and acetaminophen on the CAF anodic peak current was examined. The method was successfully applied for the determination of CAF in some practical samples.
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simultaneous determination of acetaminophen and dopamine using swcnt modified carbon ceramic electrode by Differential Pulse Voltammetry
Electrochimica Acta, 2011Co-Authors: Biuck Habibi, Mojtaba Jahanbakhshi, M H PournaghiazarAbstract:Abstract A highly sensitive method was investigated for the simultaneous determination of acetaminophen (AC) and dopamine (DA) using single wall carbon nanotubes modified carbon–ceramic electrode (SWCNT/CCE). The SWCNT/CCE displayed excellent electrochemical catalytic activities towards the oxidation of AC and DA. Under optimized experimental conditions in Differential Pulse Voltammetry technique, AC and DA gave linear response over the ranges 0.2–100.0 μM ( R 2 = 0.996) and 0.4–150.0 μM ( R 2 = 0.999), respectively. The detection limits (S/N = 3) were found to be 0.12 μM for AC and 0.22 μM for DA. The present method was applied to the determination of AC and DA in some commercial pharmaceutical samples.
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simultaneous determination of ascorbic acid dopamine and uric acid by use of a mwcnt modified carbon ceramic electrode and Differential Pulse Voltammetry
Electrochimica Acta, 2010Co-Authors: Biuck Habibi, M H PournaghiazarAbstract:Abstract Multi walled carbon nanotube modified carbon-ceramic electrode (MWCNT/CCE) was employed for the simultaneous determination of ascorbic acid (AA), dopamine (DA) and uric acid (UA). The MWCNT/CCE displayed very good electrochemical catalytic activities with respect to CCE. The oxidation over-potentials of AA, DA and UA decreased dramatically, and their oxidation peak currents increased significantly at MWCNT/CCE compared to those obtained at the bare CCE. Differential Pulse Voltammetry was used for the simultaneous determination of AA, DA and UA in their ternary mixture. The peak separation between AA and DA, and DA and UA was large up to 205 and 160 mV, respectively. The calibration curves for AA, DA and UA were obtained in the range of 15.00–800.00, 0.50–100.00, and 0.55–90.00 μM, respectively. The detection limits (S/N = 3) were 7.71, 0.31, and 0.42 μM for AA, DA and UA, respectively. The present method was applied to the determination of AA, DA and UA in human serum and some commercial pharmaceutical samples, using standard adding method and the results were quite promising.
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simultaneous determination of ascorbic acid dopamine and uric acid by use of a mwcnt modified carbon ceramic electrode and Differential Pulse Voltammetry
Electrochimica Acta, 2010Co-Authors: Biuck Habibi, M H PournaghiazarAbstract:Abstract Multi walled carbon nanotube modified carbon-ceramic electrode (MWCNT/CCE) was employed for the simultaneous determination of ascorbic acid (AA), dopamine (DA) and uric acid (UA). The MWCNT/CCE displayed very good electrochemical catalytic activities with respect to CCE. The oxidation over-potentials of AA, DA and UA decreased dramatically, and their oxidation peak currents increased significantly at MWCNT/CCE compared to those obtained at the bare CCE. Differential Pulse Voltammetry was used for the simultaneous determination of AA, DA and UA in their ternary mixture. The peak separation between AA and DA, and DA and UA was large up to 205 and 160 mV, respectively. The calibration curves for AA, DA and UA were obtained in the range of 15.00–800.00, 0.50–100.00, and 0.55–90.00 μM, respectively. The detection limits (S/N = 3) were 7.71, 0.31, and 0.42 μM for AA, DA and UA, respectively. The present method was applied to the determination of AA, DA and UA in human serum and some commercial pharmaceutical samples, using standard adding method and the results were quite promising.
Miquel Esteba - One of the best experts on this subject based on the ideXlab platform.
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study of the hg2 binding with chelation therapy agents by Differential Pulse Voltammetry on rotating au disk electrode and electrospray ionization mass spectrometry
Analytica Chimica Acta, 2009Co-Authors: Elena Chekmeneva, Jose Manuel Diazcruz, Cristina Arino, Miquel EstebaAbstract:Abstract A recently proposed electroanalytical method, using Differential Pulse Voltammetry (DPV) on the rotating Au-disk electrode, and electrospray ionization mass-spectrometry (ESI-MS) has been applied to study the binding of the pharmaceutical chelating agents meso-2,3-dimercaptosuccinic acid (DMSA), sodium 2,3-dimercaptopropanesulfate (DMPS) and d -penicillamine ( d -Pen) with Hg2+. From the use of voltammetric titrations it was possible to obtain a detailed picture of the complexation processes at concentrations much lower than in previous studies. Predominant species were Hg(Pen)2, Hg2(DMSA)2 and Hg(DMPS)2. For Pen, Hg(Pen) was also deduced from DPV data, while Hg2(Pen)4 from ESI-MS. For DMSA and DMPS, Hg2L species were detected by DPV, and Hg2L3, Hg3L3 as well as Hg2(DMPS)2 and Hg(DMSA)2 by ESI-MS. When possible, DPV data were analyzed by multivariate curve resolution with alternating least squares (MCR–ALS).
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binding of hg2 with phytochelatins study by Differential Pulse Voltammetry on rotating au disk electrode electrospray ionization mass spectrometry and isothermal titration calorimetry
Environmental Science & Technology, 2009Co-Authors: Elena Chekmeneva, Jose Manuel Diazcruz, Cristina Arino, Miquel EstebaAbstract:The binding of Hg2+ with synthetic phytochelatins ((γ-Glu-Cys)n-Gly, PCn, n = 2, 3, 4) was investigated by a recently proposed electroanalytical method, using Differential Pulse Voltammetry on the rotating Au-disk electrode, Electrospray ionization mass-spectrometry (ESI-MS) and isothermal titration calorimetry (ITC). ESI-MS experiments provided the exact stoichiometries of the complexes formed at different PCn/Hg2+ ratios. Voltammetry provided more detailed information on the complexation processes through the use of multivariate curve resolution by alternating least squares of the data matrix obtained from titrations with fine increments of metal or ligand. The system Hg2+-GSH-PC2 was investigated by Voltammetry in order to obtain an estimation of the Hg2+ behavior in the presence of two related ligands. The additional assessment of the stability of Hg2+-PCn complexes was achieved through ITC by using the therapeutic chelator sodium 2,3-dimercaptopropanesulfate (DMPS) over Hg2+-PCn systems. The stabilit...
Biuck Habibi - One of the best experts on this subject based on the ideXlab platform.
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a carbon nanotube modified electrode for determination of caffeine by Differential Pulse Voltammetry
Chinese Journal of Catalysis, 2012Co-Authors: Biuck Habibi, Mehri Abazari, M H PournaghiazarAbstract:Abstract A simple and sensitive electrochemical detection of caffeine (CAF) using a single-walled carbon nanotubes on carbon-ceramic electrode (SWCNT/CCE) is reported. CAF was oxidized at the surface of the modified electrode to produce an anodic peak at 1.38 V versus the saturated calomel electrode in 0.01 mol/L, pH 1.7 H2SO4 solution in cyclic Voltammetry. The experimental parameters, namely, type of electrolyte, pH value, and amount of SWCNTs casted, were optimized. Using the optimum conditions, the anodic peak current in Differential Pulse Voltammetry was linear with CAF concentration in the range of 2.5 × 10−7–1.0 × 10−4 mol/L. The detection limit was 1.2 × 10−7 mol/L (S/N = 3). The modified electrode exhibited good stability and can be easily regenerated. The relative standard deviation of the peak current obtained for a 5.0 × 10−5 mol/L CAF solution was 3.0%. The influence of some important biological compounds, namely, ascorbic acid, dopamine, and uric acid and addictive compounds like codeine, morphine, and acetaminophen on the CAF anodic peak current was examined. The method was successfully applied for the determination of CAF in some practical samples.
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simultaneous determination of acetaminophen and dopamine using swcnt modified carbon ceramic electrode by Differential Pulse Voltammetry
Electrochimica Acta, 2011Co-Authors: Biuck Habibi, Mojtaba Jahanbakhshi, M H PournaghiazarAbstract:Abstract A highly sensitive method was investigated for the simultaneous determination of acetaminophen (AC) and dopamine (DA) using single wall carbon nanotubes modified carbon–ceramic electrode (SWCNT/CCE). The SWCNT/CCE displayed excellent electrochemical catalytic activities towards the oxidation of AC and DA. Under optimized experimental conditions in Differential Pulse Voltammetry technique, AC and DA gave linear response over the ranges 0.2–100.0 μM ( R 2 = 0.996) and 0.4–150.0 μM ( R 2 = 0.999), respectively. The detection limits (S/N = 3) were found to be 0.12 μM for AC and 0.22 μM for DA. The present method was applied to the determination of AC and DA in some commercial pharmaceutical samples.
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simultaneous determination of ascorbic acid dopamine and uric acid by use of a mwcnt modified carbon ceramic electrode and Differential Pulse Voltammetry
Electrochimica Acta, 2010Co-Authors: Biuck Habibi, M H PournaghiazarAbstract:Abstract Multi walled carbon nanotube modified carbon-ceramic electrode (MWCNT/CCE) was employed for the simultaneous determination of ascorbic acid (AA), dopamine (DA) and uric acid (UA). The MWCNT/CCE displayed very good electrochemical catalytic activities with respect to CCE. The oxidation over-potentials of AA, DA and UA decreased dramatically, and their oxidation peak currents increased significantly at MWCNT/CCE compared to those obtained at the bare CCE. Differential Pulse Voltammetry was used for the simultaneous determination of AA, DA and UA in their ternary mixture. The peak separation between AA and DA, and DA and UA was large up to 205 and 160 mV, respectively. The calibration curves for AA, DA and UA were obtained in the range of 15.00–800.00, 0.50–100.00, and 0.55–90.00 μM, respectively. The detection limits (S/N = 3) were 7.71, 0.31, and 0.42 μM for AA, DA and UA, respectively. The present method was applied to the determination of AA, DA and UA in human serum and some commercial pharmaceutical samples, using standard adding method and the results were quite promising.
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simultaneous determination of ascorbic acid dopamine and uric acid by use of a mwcnt modified carbon ceramic electrode and Differential Pulse Voltammetry
Electrochimica Acta, 2010Co-Authors: Biuck Habibi, M H PournaghiazarAbstract:Abstract Multi walled carbon nanotube modified carbon-ceramic electrode (MWCNT/CCE) was employed for the simultaneous determination of ascorbic acid (AA), dopamine (DA) and uric acid (UA). The MWCNT/CCE displayed very good electrochemical catalytic activities with respect to CCE. The oxidation over-potentials of AA, DA and UA decreased dramatically, and their oxidation peak currents increased significantly at MWCNT/CCE compared to those obtained at the bare CCE. Differential Pulse Voltammetry was used for the simultaneous determination of AA, DA and UA in their ternary mixture. The peak separation between AA and DA, and DA and UA was large up to 205 and 160 mV, respectively. The calibration curves for AA, DA and UA were obtained in the range of 15.00–800.00, 0.50–100.00, and 0.55–90.00 μM, respectively. The detection limits (S/N = 3) were 7.71, 0.31, and 0.42 μM for AA, DA and UA, respectively. The present method was applied to the determination of AA, DA and UA in human serum and some commercial pharmaceutical samples, using standard adding method and the results were quite promising.
Ashwini K Srivastava - One of the best experts on this subject based on the ideXlab platform.
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simultaneous determination of amlodipine and losartan using an iron metal organic framework mesoporous carbon nanocomposite modified glassy carbon electrode by Differential Pulse Voltammetry
Analytical Methods, 2018Co-Authors: Anuja S Rajpurohit, Dimple K Bora, Ashwini K SrivastavaAbstract:The present work proposed a simple and convenient electroanalytical method for the selective and simultaneous determination of anti-hypertensive drugs viz. amlodipine (AML) and losartan (LOS). The electrochemical response of AML and LOS was investigated at a glassy carbon electrode (GCE) modified with an iron metal–organic framework/mesoporous carbon (FeMOF/MC) nanocomposite by employing Differential Pulse Voltammetry (DPV). Under the optimized experimental conditions, electrochemical sensing of both the molecules was performed at the FeMOF/MC/GCE in 0.1 M phosphate buffer (PBS) of pH 6.0. The DPV experiments revealed that the voltammetric signals of AML and LOS were very well resolved and separated with a potential difference of 50 mV. Also, the FeMOF/MC composite exhibited unique properties in terms of porosity, surface area and high electrical conductivity. As compared to the plain GCE, the modified electrode showed a thirteen- and nineteen-fold enhancement in the oxidation peak current of AML and LOS which indicates that the synergy of electrode materials provides excellent electrocatalytic activity towards the simultaneous determination of AML and LOS. The analytical curve of AML and LOS showed a linear response in the concentration range of 0.009 μM to 500 μM with a detection limit of 1.27 nM and 2.03 nM, respectively. The practical analytical utility of the proposed sensor was evaluated by employing the present method for simultaneous determination of AML and LOS in pharmaceutical formulations, and human blood serum, saliva and urine samples.
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enantioselective analysis of moxifloxacin hydrochloride enantiomers with graphene β cyclodextrin nanocomposite modified carbon paste electrode using adsorptive stripping Differential Pulse Voltammetry
Electrochimica Acta, 2017Co-Authors: Sharad S Upadhyay, Pramod K Kalambate, Ashwini K SrivastavaAbstract:Abstract Enantioselective analysis of Moxifloxacin hydrochloride (MOX) enantiomers was investigated on carbon paste electrode (CPE) modified with chiral selector β-Cyclodextrin and graphene nanosheets (GNS) employing adsorptive stripping Differential Pulse voltammetric (AdSDPV) technique. Electrochemical chiral discrimination was obtained due to β-Cyclodextrin, which has 35 chiral centres as a binding site resulting in very tight fit inclusion complex based on host-guest interactions. Enantioselectivity of present electrode system of graphene nanosheets and β-cyclodextrin modified carbon paste electrode (GNS-β-CD-CPE) gives difference in anodic oxidation peak potential of enantiomers S,S-MOX and R,R-MOX at 1.039 V and 0.917 V in B.R buffer solution in pH 7 confirming successful enantiomer detection respectively. Various techniques such as X-Ray diffraction (XRD), Scanning electron microscopy (SEM), Thermogravimetric analysis (TGA) and Fourier transform infra red spectroscopy (FT-IR) were employed for characterization of electrode surface. The electrocatalytic response of MOX at GNS-β-CD-CPE was measured using cyclic Voltammetry (CV) and Differential Pulse Voltammetry (DPV). Electrical conductivity of modified electrode was investigated by electrochemical impedance spectroscopy (EIS) which indicates its good conductivity over plain CPE. The proposed enantioselective electrochemical sensor was highly efficient and capable of sensing optically active isomers of MOX which is the S,S-enantiomer from its potential chiral antipode R,R-MOX enantiomer with large difference of 122 mV shift in peak potential which suggests great stereoselectivity is achieved due to chiral environment provided by chiral selector β-Cyclodextrin. Determination of percentage enantiomeric composition of S,S-MOX in racemic mixture extend future applications of chiral electroanalytical system of β-CD. In the present work, it is for the first time enantiomeric electrochemical recognition of multi-chiral drug with two chiral centres has been done voltammetrically.
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voltammetric determination of pyrazinamide at graphene zinc oxide nanocomposite modified carbon paste electrode employing Differential Pulse Voltammetry
Sensors and Actuators B-chemical, 2016Co-Authors: Pramod K Kalambate, Chaitali R Rawool, Ashwini K SrivastavaAbstract:Abstract Pyrazinamide (PZN) also called as Pyrazinecarboxamide is a widely used drug for the treatment of Tuberculosis. In the present work, we proposed a sensitive method for determination of PZN using Graphene–Zinc oxide-Carbon paste electrode (GNS-ZnO-CPE). The surface characterization of electrode materials was done by using X-Ray diffraction, Scanning electron microscopy, Energy dispersive X-ray spectroscopy and transmission electron microscopy. The electrocatalytic response of PZN at GNS-ZnO-CPE was measured using cyclic Voltammetry (CV), Differential Pulse Voltammetry (DPV) and electrochemical impedance spectroscopy (EIS). In addition, electrochemical impedance studies revealed that the smaller Rct value was observed at GNS-ZnO-CPE as compared to that of CPE, which authenticates its good conductivity. Under the optimized conditions, Ip (μA) was proportional to PZN concentration in the range of 1.5 × 10−7 to 4.0 × 10−4 M with a detection limit of 4.31 × 10−8 M. The proposed electrochemical sensor showed excellent recovery in pharmaceutical formulations, urine and blood serum samples which revealed the promising practicality of sensor for PZN detection.
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adsorptive stripping Differential Pulse Voltammetry determination of rivastigmine at graphene nanosheet gold nanoparticle carbon paste electrode
Journal of Electroanalytical Chemistry, 2015Co-Authors: Pramod K Kalambate, Madan R Biradar, Shashi P Karna, Ashwini K SrivastavaAbstract:Abstract The study of graphene nanosheet (GNS)–gold nanoparticle (AuNP)–carbon paste electrode (GNS–AuNP–CPE) as an electrochemical sensor for the determination of rivastigmine (RIV) in pharmaceuticals formulations, blood serum, and urine samples is presented. The GNS–AuNP composite is prepared by in situ simultaneous reduction of graphene oxide and chloroauric acid using sodium borohydride as a reducing agent. The GNS–AuNP composite was characterized by X-ray diffraction, UV–Vis spectroscopy, and scanning electron microscopy. Electrochemical characterization of the GNS–AuNP–CPE electrode surface was carried out by cyclic Voltammetry, electrochemical impedance spectroscopy, chronocoulometry, and adsorptive stripping Differential Pulse Voltammetry. This study shows that oxidation of rivastigmine is facilitated at the GNS–AuNP–CPE electrode and remarkably increase in current compared to the bare electrode due to enhanced adsorption of the former on electrode surface. Under the optimized conditions, the peak current (I p ) is found to be proportional to the RIV concentration in the range of 2.0 × 10 –7– 6.0 × 10 − 4 M with a detection limit of 5.3 × 10 − 8 M. The proposed sensor shows a very high level of sensitivity, selectivity, and a very good reproducibility for RIV determination. A good recovery level obtained for real samples suggests practical utility of the GNS–AuNP–CPE as an effective and reliable electrochemical sensor for RIV detection.
Dan Du - One of the best experts on this subject based on the ideXlab platform.
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Differential Pulse Voltammetry determination of ascorbic acid with ferrocene l cysteine self assembled supramolecular film modified electrode
Sensors and Actuators B-chemical, 2004Co-Authors: Shengfu Wang, Dan DuAbstract:Abstract A supramolecular film containing ferrocene (Fc) has been fabricated on l -cysteine self-assembled monolayers film modified gold electrode by electrostatic adsorption. ATR-FTIR, SEM, cyclic Voltammetry (CV), and chronocoulometry (CC) were used to determine the electrochemical properties of the supramolecular film. One reversible redox couple was observed in the pH range of 5.1–9.5, which was attributed to one-electron electrochemical process of Fc, with diffusion coefficient of 1.01×10−7 cm2 s−1. The supramolecular film showed good catalytic activity for the oxidation of ascorbic acid (AA). The catalytic current of AA versus its concentration had a good linearity in the range of 1.0×10−6 to 5.0×10−4 mol l−1, with the correlation coefficient of 0.9986 by Differential Pulse Voltammetry (DPV) and detection limit of 2.0×10−7 mol l−1. It was used for the determination of AA in practical medicine with a sensitive and accurate result.
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Differential Pulse Voltammetry determination of ascorbic acid with ferrocene l cysteine self assembled supramolecular film modified electrode
Sensors and Actuators B-chemical, 2004Co-Authors: Shengfu Wang, Dan DuAbstract:Abstract A supramolecular film containing ferrocene (Fc) has been fabricated on l -cysteine self-assembled monolayers film modified gold electrode by electrostatic adsorption. ATR-FTIR, SEM, cyclic Voltammetry (CV), and chronocoulometry (CC) were used to determine the electrochemical properties of the supramolecular film. One reversible redox couple was observed in the pH range of 5.1–9.5, which was attributed to one-electron electrochemical process of Fc, with diffusion coefficient of 1.01×10−7 cm2 s−1. The supramolecular film showed good catalytic activity for the oxidation of ascorbic acid (AA). The catalytic current of AA versus its concentration had a good linearity in the range of 1.0×10−6 to 5.0×10−4 mol l−1, with the correlation coefficient of 0.9986 by Differential Pulse Voltammetry (DPV) and detection limit of 2.0×10−7 mol l−1. It was used for the determination of AA in practical medicine with a sensitive and accurate result.