Matad Mallikarjunaiah Vinay; Kempugonapla Virupakshappa Basavarajappa; Puttaiah Manjunatha; Hanumasagara Thimmappa Purushothama; Rangapura Onkarappa Yathisha; Yanjerappa Arthoba Nayaka
Volume 12, Issue 2 , February 2020, , Pages 155-167
Abstract
A rapid electrochemical analysis of sulfadiazine (SFZ) has been carried out by cyclic voltammetry (CV) and differential pulse voltammetry (DPV) methods by employing a sensitive single walled carbon nanotube-molybdenum disulfide nanocomposite/poly ethylene glycol modified carbon paste electrode (SWCNT-MoS2/PEG/CPE). ...
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A rapid electrochemical analysis of sulfadiazine (SFZ) has been carried out by cyclic voltammetry (CV) and differential pulse voltammetry (DPV) methods by employing a sensitive single walled carbon nanotube-molybdenum disulfide nanocomposite/poly ethylene glycol modified carbon paste electrode (SWCNT-MoS2/PEG/CPE). The SFZ shows anodic peak potential at 0.94 V (vs. Ag/AgCl) in 0.1 M PBS of pH 7.0. The SFZ has been examined at different scan rate from 50 to 300 mVs-1 in 0.1 M PBS of pH 7.0 and the nature of mass transfer route is diffusion-controlled process. The different pH from 5.6 to 8.0 was analyzed at SFZ and obtained the slope value 0.063 proves the equal number of electrons and protons were involved in the reaction. In DPV mode LOD of SFZ in the linear range of 2-90 μM was found to be 1.69 μM. The prepared electrode was examined by electrochemical impedance spectroscopy (EIS) using 5 mM K3[Fe(CN)6] in 0.1 M KCl. The effective surface area of SWCNT-MoS2/PEG/CPE was found to be 0.262 cm2. This method could be successfully employed to determine the concentration of SFZ in biological fluids.
Niloofar Dehdashtian; Seyed-Ahmad Shahidi; Majedeh Bijad
Volume 12, Issue 3 , March 2020, , Pages 289-300
Abstract
Fast and sensitive response electrochemical sensor based on CoFe2O4 nanoparticle and 1-buthyl-3-methyl imidazolium bromide room temperature ionic liquids carbon paste electrode (CoFe2O4/NP/ILs/CPE) is fabricated for the determination of Xanthine (Xt) in the presences of Caffeine in fish and fruit samples. ...
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Fast and sensitive response electrochemical sensor based on CoFe2O4 nanoparticle and 1-buthyl-3-methyl imidazolium bromide room temperature ionic liquids carbon paste electrode (CoFe2O4/NP/ILs/CPE) is fabricated for the determination of Xanthine (Xt) in the presences of Caffeine in fish and fruit samples. In the first step, CoFe2O4/NP was characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD) and results showed synthesized nanoparticle with diameter between 26.92-29.22 nm. The electro-oxidation of Xt and Caffeine occurred at a potential about 0.7 V and 1.1 V, which was much better in comparison with bare carbon paste electrode in phosphate buffer (pH=6.0) at the surface of the (CoFe2O4/NP/ILs/CPE). Other electrochemical techniques were also investigated including cyclic voltammetry, differential pulse voltammetry (DPV) and chronoamperometry at CoFe2O4/NP/ILs/CPE. At optimized conditions for Xt and Caffeine analysis, DPV peak currents showed a wide linear dynamic ranging from 8.0 nM to 500 μM and detection limit for Xt was 3.0 nM and of course we obtained good dynamic range between 0.1 to 300 μM and good limit of detection 0.05 μM for caffeine. As a result, the proposed electrode could determine Xt in the presences of Caffeine in real samples with good selectivity and high sensitivity.
Hayat EL Ouafy; Tarik EL Ouafy; Mustapha Oubenali; Mohammed EL Idrissi; Malika Echajia; Aziz EL Haimouti; Mohamed Mbarki; Hassan Oulfajrite
Volume 12, Issue 2 , February 2020, , Pages 168-179
Abstract
Clay modified carbon paste electrode (CPE-C) its applicability for electroanalysis of N, N’-ethylene-2,2’-bipyridinium (diquat) has been described in the present work. Electrochemical modification was performed by electronic impedance spectroscopy (EIS) and cyclic voltammetry (CV) in the ...
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Clay modified carbon paste electrode (CPE-C) its applicability for electroanalysis of N, N’-ethylene-2,2’-bipyridinium (diquat) has been described in the present work. Electrochemical modification was performed by electronic impedance spectroscopy (EIS) and cyclic voltammetry (CV) in the range of -0.6 V to 1.2 V in 0.1 M K2SO4 (pH 3). The voltammetric method behavior of DQ is suggested where an anodic and cathodic peak appeared at Epa=0.55 V and Epc=0.1 V, successively. These peaks obtained from the reversible redox of DQ at the CPE-C surface. The optimal preconcentration time and percentage of clay insert were 10 min and 20% respectively. The proposed method exhibits certainly an electro-catalytic success toward DQ redox. The peaks current recorded using cyclic voltammetry has been linearly dependent on the DQ concentration ranging from 1×10-5 to 5×10-5 molL-1. The detection limit (DL) calculated for the anodic peak is 5.33×10-8 molL-1. Then relative standard deviation for 2×10-5 molL-1 diquat has been 4.3% for nine repetitions. The proposed detector has been successfully applied for DQ electroanalysis in a river water sample with a DL of 8.17×10-8 molL-1.
Arash Fattah-alhosseini; Kazem Babaei
Volume 12, Issue 3 , March 2020, , Pages 301-317
Abstract
Mg alloys have a vast usage where weight reduction is really significant since they do the features really well for materials of ultra-light weight. However, Mg is inherently a reactive metal and its alloys generally possess quite weak corrosion resistance that widely restricts their technological usages, ...
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Mg alloys have a vast usage where weight reduction is really significant since they do the features really well for materials of ultra-light weight. However, Mg is inherently a reactive metal and its alloys generally possess quite weak corrosion resistance that widely restricts their technological usages, especially in some rough service conditions. Despite, many investigations on the passive and electrochemical properties of Mg alloys and their relation with the microstructure of these alloys, few reports have been devoted to investigate the semiconducting behavior of the formed oxide layers on these alloys. Mott–Schottky measurement is a major in-situ technique to analyze semiconductor behavior of passive layers. In this review, the semiconducting properties of formed passive layers on Mg alloys (AZ91D, AZ31B, AZ80, Mg-Y-Rare Earth-Zr alloys) by Mott–Schottky measurement has been assessed. Mott–Schottky measurements revealed the formed passive films on Mg alloys show mainly n-type behavior regardless the microstructure, pH, immersion time, and temperature of electrolyte.
Soheyla Sharif Manesh; Mahboubeh Masrournia; Ali Beyram Abady
Volume 12, Issue 2 , February 2020, , Pages 180-192
Abstract
In the study, novel and sensitive carbon paste electrodes (CPEs) developed for thepotentiometric measurement of Cr(III) and Mg(II) ions in pharmacological and water samples.CPEs as indicator electrodes were prepared from a mixture of four components, includinggraphite powder, paraffin oil, multi-walled ...
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In the study, novel and sensitive carbon paste electrodes (CPEs) developed for thepotentiometric measurement of Cr(III) and Mg(II) ions in pharmacological and water samples.CPEs as indicator electrodes were prepared from a mixture of four components, includinggraphite powder, paraffin oil, multi-walled carbon nanotubes (MWCNTs), and a greenionophore (Chitosan Schiff base derivative). Optimization of CPE composites indicated thatthe critical factor in the preparation of the CPEs was chitosan Schiff base derivative whichselectivity proposed sensors highly depended on this factor. Effects of various parameters suchas pH, lifetime, response time, and selectivity of the potentiometric sensors to determine Cr(III)and Mg(II) ions were also evaluated. The results indicated that the proposed sensors can beapplied in a relatively wide range of pH, long lifetimes, short response times, and excellentselectivity for the analyte determination. The prepared sensors show Nernstian slopes of 19.53and 29.83 mVdecade−1, and LODs of 5.6×10– 8 and 4.4×10−9 with RSDs lower than 2.3% forCr(III) and Mg(II) ion determination, respectively. The calibration curves were linear in theconcentration ranges of 1.0×10-7-1.0×10-2 and 1.0×10-8-1.0×10-3 M, and R-square of 0.989 and0.987 for the measurement of Cr(III) and Mg(II) ions, respectively. Besides, the sensors weresuccessfully utilized for the Cr(III) and Mg(II) ion measurement in real samples such as tabletand tap water samples with suitable recovery higher than 97.6%.
Vinod Kumar Vashistha; Deepak Kumar Das; Anubha Yadav; Deepak Saini; Anuj Kumar
Volume 12, Issue 3 , March 2020, , Pages 318-328
Abstract
Macrocycles and p-benzoquinones (p-BQ) have been generally connected as potential co-synergist redox models in aerobic oxidation. To get insight for the synergist oxidation of hydroquinones (H2Q), thus, we synthesized and characterized dibenzotetraaza [14]annulene type macrocycles of FeIII and CoII metal ...
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Macrocycles and p-benzoquinones (p-BQ) have been generally connected as potential co-synergist redox models in aerobic oxidation. To get insight for the synergist oxidation of hydroquinones (H2Q), thus, we synthesized and characterized dibenzotetraaza [14]annulene type macrocycles of FeIII and CoII metal ions and described by utilizing different examinations including molar conductance, IR, UV-Vis, mass and cyclic voltammetric measurements. The spectroscopic and computational studies proposed that the macrocycles have saddle shape distorted octahedral structure. These macrocycles demonstrated the reversible and quasi-reversible redox process pursued by Randles-Sevcik equation, demonstrating the adjustment of unusual oxidation conditions of metal ions. Further, the experimental consequences presented herein enlighten the catalytic activity of these macrocycles towards the oxidation of H2Q. The results indicated that in the absence of macrocycles, the molecular oxygen is inactive with H2Q but in presence of synthesized macrocycles H2Q initiates prompt oxidation with the production of H2O2. Moreover, CoII macrocycle was found to be an efficient catalyst for the oxidation of H2Q into corresponding benzoquinones.
Moha Afrokh; Said Baroud; Mohamed Rbaa; Issam Sadki; Abdelhakim Hatimi; Saida Tahrouch; Mohamed Tabyaoui; Abdellah Guenbour; Ismail Warad; Abdelkader Zarrouk
Volume 12, Issue 2 , February 2020, , Pages 193-207
Abstract
This study set out to examine the cystoseira gibraltarica extract (CG) as an environmentally sustainable corrosion inhibitor for carbon steel in 1.0 M HCl medium. The corrosion inhibiting effect has been studied by conventional methods such as gravimetric (weight loss) and electrochemical (EIS and PDP) ...
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This study set out to examine the cystoseira gibraltarica extract (CG) as an environmentally sustainable corrosion inhibitor for carbon steel in 1.0 M HCl medium. The corrosion inhibiting effect has been studied by conventional methods such as gravimetric (weight loss) and electrochemical (EIS and PDP) methods. All the methods used in this study confirm that cystoseira gibraltarica extract has a potential inhibitory effect of carbon steel in hydrochloric acid medium. The inhibitory efficiency reached at a maximum value of 90.3% at a concentration of 0.8 g/L, this efficiency was slightly decreased at high temperature. The results obtained by the polarization show that this ecological inhibitor acts as a mixed inhibitor. The parameters thermodynamics show that the studied inhibitor is adsorbed on the metal surface following Langmuir isotherm.
Faiza Kakaa; Mosbah Ferkhi; Mesbah Lahouel
Volume 12, Issue 3 , March 2020, , Pages 329-344
Abstract
The objective of this work was to demonstrate the effect of fluoride and propolis extract on the corrosion behavior of commercially pur titanium (cp-Ti grade 2) in artificial saliva. The inhibition studies were approved out on cp-Ti as dental implant in Fusayama-Meyer with the propolis extract using ...
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The objective of this work was to demonstrate the effect of fluoride and propolis extract on the corrosion behavior of commercially pur titanium (cp-Ti grade 2) in artificial saliva. The inhibition studies were approved out on cp-Ti as dental implant in Fusayama-Meyer with the propolis extract using potentiodynamic polarization and Electrochemical Impedance Spectroscopy (EIS). Parameters, such as concentration of the inhibitor, time of immersion were varied and optimized. The results showed that either the NaF or the presence of propolis extract in medium saliva had a significant influence on the corrosion rate (Icorr) and polarization resistance (Rp): the Icorr value increased and Rp decreased in medium containing fluoride, but the presence of propolis in media improved the corrosion resistance of this metal.
Santosh B. Konnur; Sharanappa T. Nandibewoor
Volume 12, Issue 2 , February 2020, , Pages 208-222
Abstract
Electro analysis of 2-Aminothiazole (2-AT) by a low cost poly Glycine modified Pencil Graphite Electrode (poly Gly/PGE) was studied using of cyclic voltammetric (CV) and differential pulse voltammetric (DPV) techniques. The optimal experimental conditions to determine 2-AT was setup by the variation ...
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Electro analysis of 2-Aminothiazole (2-AT) by a low cost poly Glycine modified Pencil Graphite Electrode (poly Gly/PGE) was studied using of cyclic voltammetric (CV) and differential pulse voltammetric (DPV) techniques. The optimal experimental conditions to determine 2-AT was setup by the variation of the current with scan rate, concentration and pH. Electrochemical performance of the 2-AT at poly Gly/PGE was found adsorption-controlled reaction. A plausible electro oxidation mechanism was proposed. The anodic peak current of DPV was found to be linearly proportional to the 2-AT concentrations in the range from 1.0×10-6 to 12.0×10-6 M with a detection limit 7.29×10-8 M with better selectivity and sensitivity under the optimal conditions. Quantitative analysis of 2-AT levels in urine as real sample was carried out by applying this proposed method. Moreover, some common interfering substances were used to the study of interference. The clinical and quality control laboratories can employ this method to determine 2-AT.
Rubin Gulaboski; Pavlinka Kokoskarova; Sofija Petkovska
Volume 12, Issue 3 , March 2020, , Pages 345-364
Abstract
In this review, we focus on cyclic voltammetry as a reliable electrochemical technique to study mechanisms, kinetics and thermodynamics of various types of drug-drug interactions. While we present and discuss six theoretical models relevant to analyze drug-drug (or drug-DNA) interactions, we also give ...
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In this review, we focus on cyclic voltammetry as a reliable electrochemical technique to study mechanisms, kinetics and thermodynamics of various types of drug-drug interactions. While we present and discuss six theoretical models relevant to analyze drug-drug (or drug-DNA) interactions, we also give hints about recent experimental achievements in this field. In addition, we provide the readers several sets of simulated voltammograms and data in tabular form, which can be used to recognize particular mechanism of drug-drug interactions in cyclic voltammetry. Moreover, we give hints to the voltammetric procedures that allow access to kinetics and thermodynamics parameters, which are relevant to various types of drug-drug interactions. The results we present in this work can be of big help to the scientists working in the field of pharmacy, pharmacology, medicinal chemistry and bio-electrochemistry.
Ahmed A. Habib; Hassan A. M. Hendawy; Sherin F. Hammad; Lories I. Bebawy; Marian A. Girges
Volume 12, Issue 2 , February 2020, , Pages 223-237
Abstract
The electrochemical behavior of tetrahydrozoline (THZ) was explored by cyclic voltammetry and differential pulse voltammetry. A well-defined peak at 915 mV using gold nanomodified electrode (AuNPts/CP) in presence of sodium dodecyl sulphate (SDS) was detected. Different buffers, pH and scan rates on ...
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The electrochemical behavior of tetrahydrozoline (THZ) was explored by cyclic voltammetry and differential pulse voltammetry. A well-defined peak at 915 mV using gold nanomodified electrode (AuNPts/CP) in presence of sodium dodecyl sulphate (SDS) was detected. Different buffers, pH and scan rates on oxidation peak current were studied. Linear calibration curve was achieved in the range of 1.99×10−5 to 7.79×10-5 M with a limit of detection (LOD) 5.54×10-6 M and limit of quantification (LOQ) 1.69×10−5 M, respectively.The suggested method was successfully utilized to the eye drops dosage form and urine sample with percentage recovery, 98.86%±0.77, and 101.13±0.62, respectively.
Ameneh Amani; Mahdi Jamshidi
Volume 12, Issue 3 , March 2020, , Pages 365-375
Abstract
Electrochemical oxidation of leaves extract of lemon verbena and the flowers extract of echium amoenum have been studied in the absence and presence of barbituric acid and 1,3 dimethyl barbituric acidin aqueous solutions and biological pH, using cyclic voltammetry method. The results showed that the ...
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Electrochemical oxidation of leaves extract of lemon verbena and the flowers extract of echium amoenum have been studied in the absence and presence of barbituric acid and 1,3 dimethyl barbituric acidin aqueous solutions and biological pH, using cyclic voltammetry method. The results showed that the electrochemically generated compounds in leaves extract of lemon verbena and the flowers extract of echium amoenum, participate in the chemical reaction with barbituric acid and 1,3 dimethyl barbituric acid. Based on our results, leaves extractof lemon verbena and the flowers extract of echium amoenum have a high antioxidant activity in comparison with galic acid, salicylic acid and quercetin as standard antioxidants and simultaneous can be useful for the treatment of barbiturate poisoning before starting clinical treatments. The antioxidant activity of luteoline and verbascoside (as the main and natural compounds in lemon verbena) against some of the reactive oxygen species (ROS) generation enzymes, Cytochrome P450 3A4 (4D75), Myeloperoxidase (1DNW) and Thyosine (3nm8) has been performed through molecular docking studies. The results indicated that these natural compounds bound exclusively to the binding site of ROS generation enzymes and has a remarkable role in suppressing the destructive effects of oxidative stress in the biological system of the human body.
Shokoofeh Sheibani; Seyed Iman Mirzaie; Mehdi Fardmanesh; Parviz Norouzi
Volume 12, Issue 2 , February 2020, , Pages 238-249
Abstract
A novel recognition method for selective determination of the hyoscine N-Butyl bromide (HBB), an antispasmodic agent for smooth muscles, was devised using extended gate field-effect transistor (EG-FET) as transducing unit. For this purpose a PVC membrane, containing hyoscine n-butyl-tetraphenyl borate ...
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A novel recognition method for selective determination of the hyoscine N-Butyl bromide (HBB), an antispasmodic agent for smooth muscles, was devised using extended gate field-effect transistor (EG-FET) as transducing unit. For this purpose a PVC membrane, containing hyoscine n-butyl-tetraphenyl borate ion-pair as recognition component, was coated on Ag/AgCl wire, which was connected to the extended metal gate. In optimal conditions, the linear range for HBB was 10-8-10-5 molL−1 with limit of detection 1.7×10-9 molL-1. The proposed sensor was applied in real sample, it showed fast response with high accuracy, and therefore it could be used as HPLC detector in the pharmaceutical samples in quality control.
Esmat Shojaeia; Mahboubeh Masrournia; Ali Beyramabadi; Hossein Behmadi
Volume 12, Issue 3 , March 2020, , Pages 376-391
Abstract
The strontium ion, in water-soluble forms, is one of the major pollutant in drinking water. Therefore, a simple, rapid, selective, and sensitive potentiometric carbon paste electrode was developed to measure strontium ion in real samples with complex matrices. To prepare the potentiometric sensor, a ...
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The strontium ion, in water-soluble forms, is one of the major pollutant in drinking water. Therefore, a simple, rapid, selective, and sensitive potentiometric carbon paste electrode was developed to measure strontium ion in real samples with complex matrices. To prepare the potentiometric sensor, a synthetic ligand ((E)-4-(((2-amino-4-chlorophenyl)imino)methyl)-5-(hydroxymethyl)-2-methyl pyridine-3-ol) as an efficient ionophore and an ionic liquid (1-Butyl-3-methylimidazolium hexafluorophosphate) as a suitable binder were dispersed in a mixture of graphite powder and graphene oxide. The composition of the sensor was optimized using a central composite design (full factorial) to reduce the number of experimental runs and investigate interactions between effective factors. The proposed sensor showed a Nernstian behavior in the linear concentration range of 1×10-8 to 1.0×10-1 M with a low detection limit (1.59×10−9 M) and suitable relative standard division (1.01 %). The proposed sensor can be well applied in the pH range of 3.00-9.50 for the analyte determination. Moreover, the proposed electrode as an indicator electrode was successfully used to measure the Sr(II) concentration in the depilatory powder, toothpaste, and raticide samples.
Taher Alizadeh; Somayeh Amjadi
Volume 12, Issue 2 , February 2020, , Pages 250-262
Abstract
The foregone studies have shown that nicotinic acid cannot produce noticeable reductive signal at carbon-based electrodes without appropriate modification of the electrode. This is an obvious reason that mercury is known as the main electrode material for electro-reduction of nicotinic acid. In this ...
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The foregone studies have shown that nicotinic acid cannot produce noticeable reductive signal at carbon-based electrodes without appropriate modification of the electrode. This is an obvious reason that mercury is known as the main electrode material for electro-reduction of nicotinic acid. In this study, it has been shown that it is possible to create a remarkable reduction signal for NA at a carbon paste electrode (CPE) without any modification. This achieved by precisely adjustment of electroanalysis pH, appropriately choosing of binder kind, precisely controlling of the percentage of the binder in the electrode composition and utilizing of an effective voltammetric technique. A carbon paste electrode, containing 30% of n-eicosane (as binder) was shown to be the best electrode for NA determination. It was also shown that utilizing of square wave voltammetry in place of differential pulse voltammetry led to remarkably improvement in the analytical signal of NA. The pH value of the electroanalysis solution was shown to be a crucially effective factor for creating of NA signal and an optimum value of pH equal to 2.2 was chosen as the best pH condition. The optimized method exhibited a dynamic concentration linear range of 3.0×10−6-3.0×10−3 molL-1 with a detection limit of 5.63×10−7 molL-1. As an analytical application, the proposed sensor was successfully used for determination of nicotinic acid in the urine, serum and pharmaceutical samples.
Baha Öndeş; Mihrican Muti
Volume 12, Issue 3 , March 2020, , Pages 392-401
Abstract
Disposable, selective and low-cost carbon nanotube modified electrodes were fabricated for the electrochemical detection of neonicotinoid insecticide, Clothianidin (CLT). Almost 2 folds’ increase at Clothianidin reduction signal was obtained by using single-walled carbon nanotube modified electrodes ...
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Disposable, selective and low-cost carbon nanotube modified electrodes were fabricated for the electrochemical detection of neonicotinoid insecticide, Clothianidin (CLT). Almost 2 folds’ increase at Clothianidin reduction signal was obtained by using single-walled carbon nanotube modified electrodes (SWCNT-PGE) compared to unmodified electrodes. These nanomaterials modified electrodes developed in this study will enable simple, rapid and inexpensive identification of the neonicotinoid insecticides, Clothianidin and it is hoped that this technique developed by using these nanosensors will be an alternative to the expensive and time consuming chromatographic techniques with its advantages of adapting to the sensor chip technology for the routine analysis of agricultural products.
Hamid Reza Naderi; Ali Sobhani-Nasab; Esmail Sohouli; Kourosh Adib; Ebrahim Naghian
Volume 12, Issue 2 , February 2020, , Pages 263-276
Abstract
Nanoparticles of ytterbium tungstate prepared through the direct addition of an Yb3+ solution to a tungstate solution, were computed through Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS). Further the supercapacitive characteristics ...
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Nanoparticles of ytterbium tungstate prepared through the direct addition of an Yb3+ solution to a tungstate solution, were computed through Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS). Further the supercapacitive characteristics of the nanoparticles, as a potential material for constructing electrodes, were evaluated through cyclic voltammetry (CV), galvanostatic charge/discharge (GCD) and electrochemical impedance spectroscopy (EIS). Electrodes made of the Yb2(WO4)3 had a specific capacitance (SC) value of 336 F g-1 in a 2.0 M H2SO4 solution at a potential scan rate of 2 mV s-1; and 298 F g-1 at a current density of 1 A g-1 based on GCD tests. The electrodes also revealed to have a 95.8% cycling durability after 4000 potential cycles.
Maryam Malekzadeh; Alireza Mohadesi; Mohammad Ali Karimi; Mehdi Ranjbar
Volume 12, Issue 3 , March 2020, , Pages 402-414
Abstract
In this study, a new molecularly imprinted polymer with nanoporous material of zirconium metal-organic frameworks (Zr-MOF/MIP) for diclofenac (DFC) measurement is presented. The Zr-MOF/MIP was prepared by electropolymerization method, the Zr-MOFs were used to increase electrode surface and the DFC and ...
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In this study, a new molecularly imprinted polymer with nanoporous material of zirconium metal-organic frameworks (Zr-MOF/MIP) for diclofenac (DFC) measurement is presented. The Zr-MOF/MIP was prepared by electropolymerization method, the Zr-MOFs were used to increase electrode surface and the DFC and para- aminobenzoic acid (pABA) were used as template and functional monomer, respectively. Zr--MOFs was characterized by using X-ray powder diffraction (XRD), scanning electron microscope (SEM) and Fourier transform infrared spectroscopy (FTIR). The electrochemical performance was investigated using cyclic voltammetry (CV) and differential pulse voltammetry (DPV). Sensor response was evaluated by comparing the electrochemical response of Zr-MOF/MIP, with that of non- Imprinted polymer (NIP), in a 2.0 mM potassium ferrocyanide solution containing 0.2 mM sodium sulfate as probe solution. Measurements were carried out in the potential range of -0.6 to +1.0 V with scan rate of 50 mV/s. The calibration curve of diclofenac was linear in the concentration range of 6.5 μM to 1.5×10+3 μM. Detection limit was obtained 0.1 μM and relative standard deviation of several (n=7) replicate measurements for 1.0 mM DFC concentration has obtained 1.8%. Furthermore, favorable sensitivity, selectivity, good reproducibility and long-term stability, was obtained in the experiment and the proposed electrode was applied for the determination of DFC in pharmaceutical commercial sample with satisfactory results.
Mohammad Mazloum-Ardakani; Ali Mohammad Dehghani-Tafti
Volume 12, Issue 2 , February 2020, , Pages 277-288
Abstract
The electrochemical properties of a modified carbon paste electrode with the synthesized compound of 2,2'-[1,7–heptanediylbis(nitrilomethylidene)]-bis(4-hydroxyphenol) (DHBH) and graphite nanoparticle (GN) were studied by cyclic voltammetry (CV), chronoamperometry and differential pulse voltammetry ...
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The electrochemical properties of a modified carbon paste electrode with the synthesized compound of 2,2'-[1,7–heptanediylbis(nitrilomethylidene)]-bis(4-hydroxyphenol) (DHBH) and graphite nanoparticle (GN) were studied by cyclic voltammetry (CV), chronoamperometry and differential pulse voltammetry (DPV) methods. The proposed electrode shows excellent electrocatalytic activity towards the oxidation of NADH under the optimum pH of 7.0. The modifier and nanoparticle simultaneously lead to a reduce overpotential of NADH oxidation about 250 mV and enhance current about 6 μA of the unmodified CPE. This electrochemical sensor exhibited a detection limit (3σ) of 13.4 nM with two linear dynamic ranges (0.01-6.0 and 6.0-400.0 μM) for the determination of NADH. The modified electrode can detect well NADH (180 mV) in the presence of Uric acid (360 mV) simultaneously. Also, the performance of the proposed sensor was evaluated in real samples.
K. S. Ashoka; G. P. Mamatha; H. M. Santhosh
Volume 12, Issue 3 , March 2020, , Pages 415-424
Abstract
Isatins, derivatives of indole, represent important class of compounds belonging to nitrogen heterocycles. These compounds comprise synthetically vital substrates that are used as precursors for drug synthesis and raw materials for heterocycles etc. Research in this group of compounds has engrossed interest ...
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Isatins, derivatives of indole, represent important class of compounds belonging to nitrogen heterocycles. These compounds comprise synthetically vital substrates that are used as precursors for drug synthesis and raw materials for heterocycles etc. Research in this group of compounds has engrossed interest among scientific community in recent and past as Isatins are known to possess immense biological activities. Present work delineates synthesis, characterization, electrochemical and antimicrobial studies of four substituted derivatives of isatin derivatives. The cyclic voltammetric studies of all the analytes showed that four derivatives have better electro catalytic activity towards the analytes at glassy carbon electrode. These synthesized isatin derivatives were screened for their antimicrobial activity against Gram-negative bacteria (Escherichia coli and Staphylococcus aureus) and fungi such as Candida albicans and Penicillin chrysogenum, and found to possess considerable antimicrobial activity suggesting their effectiveness in developing antibiotics and novel drugs.