Selective Carbon Paste Electrode Research Articles

A highly selective carbon paste electrode enhanced by Cu‐encapsulated poly(amidoamine) for the simultaneous detection of organic and inorganic contaminants

AbstractIn this study, a copper/poly(amidoamine)/multi‐walled carbon nanotube/reduced graphene oxide (Cu/PAMAM/MWCNT/rGO) complex was synthesized for fabricating an electrochemical sensor to simultaneously detect nitrate and nitrite ions as inorganic contaminants, and 4‐chlorophenol (4‐CP) and 1,2,5,8 tetrahydroxy anthraquinone (THA) as organic pollutants. The prepared Cu/PAMAM/MWCNT/rGO electrode was characterized using scanning electron microscopy (SEM), Fourier‐transform infrared (FT‐IR), X‐ray diffraction (XRD), X‐ray photoelectron spectroscopy (XPS), and electrochemical impedance spectroscopy (EIS). Cyclic voltammetry (CV) was performed to investigate the influence of the pH of the solution, concentration of anions, and scan rate on the analytical performance of the electrodes. The simultaneous determination of nitrite/nitrate ions using a Cu/PAMAM/MWCNT/rGO electrode showed sensitivities of 8.030 × 10−3 and 5.370 × 10−3 μA μM−1 mm−2, and limits of detection (LODs) of 0.081 and 0.115 μM, respectively. For the simultaneous determination of 4‐CP/THA, the sensitivities of the modified electrode were 0.0105 and 9.399 × 10−3 μA μM−1 mm−2, and detection limits were 0.062 and 0.070 μM respectively.

New disposable ion-selective sensors for the determination of dabigatran etexilate: The oral anticoagulant of choice in patients with non-valvular atrial fibrillation and COVID-19 infection

Selective, sensitive, and reproducible ion-selective electrodes containing dabigatran etexilate- phosphotungstate ion pair as a modifier have been fabricated to determine dabigatran etexilate in pure and pharmaceutical dosage form. The modified electrodes ion selective carbon paste electrode and ion selective pencil graphite electrode showed fast and linear responsewithin a concentration range of 1.0 × 10−5to 1.0 × 10−2 M and 1.0 × 10−6to 1.0 × 10−2 M with a detection limit of 4.36 × 10−6 M and 4.26 × 10−7 M by ISCPE and ISGPE, respectively. Electrodes are selective to dabigatran etexilate over common excipients. The present study demonstrated the determination of dabigatran etexilate in pure and pharmaceutical dosage forms with high accuracy and precision.

Electrochemical Determination of Pb(II) Using Carbon Paste Electrodes Modified with Ion Imprinted Polymers (IIPs)

An easy, low-cost, and highly selective carbon paste electrode based on an ion-imprinted polymer (IIP) to determine Pb(II) in real samples was developed. The recognition cavities based on a cross-linked polymer selective to Pb(II) were created using vinyl pyridine. The modified CPE was constructed by a composite mixture with the synthesized IIP. A notable difference was observed in the electrochemical response of the electrodes modified with the IIP and a non-imprinted polymer, demonstrating the unique properties of the IIP recognition sites. The parameters related to the current intensity were optimized; the selectivity was also studied considering potential interference ions. The proposed modified electrode demonstrated to be as (or more) selective to Pb(II) compared to others previously reported in the literature. A linear concentration range from 3.3 mg/L to 33 mg/L with a limit detection of 1 mg/L was obtained. The Pb(II) preconcentrated on the electrode surface was successfully quantified in real potable water samples without previous treatment.

A Highly Selective Carbon Paste Electrode Enhanced by Cu-Encapsulated Pamam for the Simultaneous Detection of Organic and Inorganic Contaminants

A Highly Selective Carbon Paste Electrode Enhanced by Cu-Encapsulated Pamam for the Simultaneous Detection of Organic and Inorganic Contaminants

Electrochemical sensing of antibiotic drug amoxicillin in the presence of dopamine at simple and selective carbon paste electrode activated with cetyltrimethylammonium bromide surfactant

Electrochemical sensing of antibiotic drug amoxicillin in the presence of dopamine at simple and selective carbon paste electrode activated with cetyltrimethylammonium bromide surfactant

Novel Fe2O3@CeO2 Coreshell‐based Electrochemical Nanosensor for the Voltammetric Determination of Norepinephrine

AbstractA new selective carbon paste electrode (CPE), was applied as an electrochemical sensor for the detection of norepinephrine (NOE). The sensor was modified with 6‐amino‐4‐(3,4‐dihydroxyphenyl)‐3‐methyl‐1,4‐dihydropyrano[2,3‐c],pyrazole‐5‐carbonitrile (ADPC) assisted Fe2O3@CeO2 coreshell nanoparticles (CNs) synthesized by simple method. To identify the redox properties of the modified electrode, and to examine its electrochemical properties, cyclic voltammetry (CV), chronoamperometry and differential pulse voltammetry (DPV) were conducted. Through electrochemical investigations, the coefficient of electron transfer between ADPC and the CNs/CPE (i. e. carbon paste electrode which was modified with CNs), the apparent charge transfer rate constant (ks), and the diffusion coefficient (D) were calculated. The NOE oxidation occurred at the optimum pH of 7.0 and a potential that was about 235 mV less positive than that of the unmodified carbon paste electrode. The interaction between the two metals in the Fe2O3@CeO2 coreshell led to an increase in the surface area and, consequently a sharp increase in the current. The differential pulse voltammogram of NOE showed two linear dynamic ranges an excellent detection limit (3σ) of 40 nM. In addition, NOE, AC and Trp were simultaneously determined at the modified electrode. Finally, NOE was quantitated in a number of real samples.

Preparation of Molecularly Imprinted Magnetic Graphene Oxide-Gold Nanocomposite and Its Application to the Design of Electrochemical Sensor for Determination of Epinephrine

In this study, a new molecularly imprinted polymer (MIP) based nanocomposite was synthesized then used to determine epinephrine (EPN) by the use of an electrochemical sensor modified by it. Typical techniques for the synthesis of MIP have disadvantages, such as weak binding sites, low mass transfer and low selectivity. One of the ways to improve electrochemical properties is the use of graphene oxide (GR-Ox) and modification of its surface. For this purpose, GR-Ox was initially magnetized (MGR-Ox), then its surface was coated with a silica layer, and gold nanoparticles (AuNPs) were coated on its surface. Subsequently, copolymerization of methacrylic acid (MAA) and N,N'-methylene-bis-acrylamide (MBA) in the presence of EPN was performed on the MGO-AuNPs surface. Afterwards, a selective carbon paste electrode (CPE) with synthetic nanocomposite was fabricated to detect EPN. Under optimal conditions, a linear range from 10-8 to 5.0 × 10-7 M was obtained for the measurement of EPN in urine and blood with a detection limit of 5 × 10-9 M (S/N = 3).

Application of general regression neural network and central composite design in fabrication and performance of magnetite (Fe3O4) modified carbon paste electrode for the electrochemical detection of Clomiphene

In this research, a novel, simple, sensitive and selective Carbon paste electrode (CPE) modified with Iron Oxide (Fe3O4) nanoparticles is constructed and used for the Voltammetric determination of Clomiphene. The synthesized Fe3O4 nanoparticles are characterized by routine methods such as scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR) and Atomic Force Microscope (AFM). Also, Clomiphene Redox behavior was examined by Differential pulse voltammetry (DPV) technique. An experimental Design model was developed to predict the behavior of a series of parameters including pH, concentration of modifier, step potential and amplitude on the electrochemical response of Clomiphene on the modified electrode. The obtained results showed that, the phosphate buffer with pH 4.0 was the best medium for reduction of Clomiphene on the modified carbon past electrode. The range of linearity was found to be from 1 to 727 μM (R2 = 0.9722). Finally, the response of electrode in the optimum conditions was modeled using general regression of neural networks and results were compared with common linear calibration.

Application of 1,4-Diaminoanthraquinone as a New Sensing Material for Fabrication of a Iron(III)-Selective Modified Carbon Paste Electrode

In the present work, a novel sensitive electrochemical potentiometric sensor for sensing Fe3+ ions based on 1,4-diaminoanthraquinone (DAQ) as a hydrophobic selector element was prepared to implement as an ion selective carbon paste electrode in the aqueous solutions. The adequate amounts of ionophore (5%), paraffin oil (25%) as a binder, Nanosilica (NS: 0.5%) multi-wall carbon nanotubes (MWCNTs: 1%) as a modifier, and graphite powder (68.5%) as an inert matrix was occupied to form the paste. This new FeCP sensor demonstrated a Nernstian slope of 19.7 ± 0.7 mV per decade over widish linear range between 1.0 × 10–8 to 1.0 × 10–2 mol L–1 at working pH range of 1.9–5.0 in the optimized conditions. The average elapsed time to response of electrode was about ~6 s for concentrations from lower (1.0 × 10−8 mol L–1) to higher (1.0 × 10−2 mol L–1) of Fe3+ ion solution. The selectivity of electrode toward Fe3+ ions in comparison with other cations was studied by matched potential method. The making FeCP sensor has been put to use successfully as an indicator electrode in analytical applications such as the potentiometric titration and determination of iron(III) ion in blend of different ions.

Synergistic Effect of ZnO Nanoparticles and Carbon Nanotube and Polymeric Film on Electrochemical Oxidation of Acyclovir.

A simple and selective carbon paste electrode has been developed for the electrochemical determination of acyclovir (ACV). This electrode was designed by incorporation of multi-walled carbon nanotubes (MWCNTs) and ZnO nanoparticles into the carbon paste matrix, and then poly (o-aminophenol; OAP) film were subsequently electropolymerized on it. The surface structure of nanoparticles were characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Surface morphology and electrochemical properties of the prepared nanocomposite modified electrode were investigated by SEM and cyclic voltammetry (CV). The calibration graph was linear over the concentration range 0.089 to 7.96 µg mL-1 for ACV determination with a detection limit of 0.067 µg mL-1. The proposed electrode was successfully applied for ACV determination in pharmaceutical formulations with satisfactory results.

Synthesis and Application of MWCNT-SPIMP as a Suitable Neutral Carrier for Construction of New Copper Selective Carbon Paste Electrode

Synthesis and Application of MWCNT-SPIMP as a Suitable Neutral Carrier for Construction of New Copper Selective Carbon Paste Electrode

Determination of Thallium(I) by Hybrid Mesoporous Silica (SBA-15) Modified Electrode

Chemically modified mesoporous silica material (SBA-15) was used for the construction of Tl(I) selective carbon paste electrode. The best response was found with the electrode containing 10% modifier as electrode material. The electrode has a lower detection limit of 6.0 × 10−9 M in a working concentration range of 1.0 × 10−8–1.0 × 10−1 M. The selectivity coefficient calculated by match potential method (MPM) shows the high selectivity of electrode towards Tl(I) over other tested ions. The electrode was successfully applied as an indicator electrode for the titration of 0.01 M TlNO3solution with standards EDTA solution and for sequential titration of mixture of different anions.

Preparation of Iodide Selective Carbon Paste Electrode with Modified Carbon Nanotubes by Potentiometric Method and Effect of CuS‐NPs on Its Response

AbstractIn this research, multiwalled carbon nanotubes (MWCNTs) was oxidized and chemically modified through reaction with 3‐(trimethoxysilyl)propan‐1‐amine (TMSPA) and their subsequent reaction with 2‐hydroxy‐3‐methoxy benzaldehyde. Subsequently, this material was metalized by reaction with copper acetate that lead to formation and impergeation of 2‐methoxy‐6‐((3‐(trimethoxysilyl)propylimino)methyl)phenol MMSPIMPMWCNT‐Cu. This novel material was identified with different techniques such as SEM and FT‐IR analysis. In this work, the reported material are exhibited high accurate and repeatable monitoring of iodide due to its high surface area with various reactive centre. It exhibited selectivity for iodide over the wide linear dynamic range between 1.8×10−6 and 1.15×10−1 M, with a Nernstian slope of −59.12±0.7 mV per decade of activity and detection limit of 1.8×10−6 M. Copper sulfide nanoparticles were prepared and their effect on the electrode response was investigated. The results were improved in the presence of nanoparticles with fast and stable response, good reproducibility, long‐term stability, high selectivity over the presence of common organic and inorganic anions, high detection limit and dynamic range. The proposed sensor has been applied as potentiometric determination of some iodine species over a pH range of 2.5–10.

Synthesis and characterization of novel tetra cyclo[4]pyrrole ether as an anion recognition element for nanocomposite nitrate ion selective carbon paste electrode

Novel tetra cyclo[4]pyrrole ether cation (C4PE) was synthesized and characterized by different spectroscopy methods. Cyclo[4]pyrrole ether was synthesized by oxidation reaction of pyrrole with Cu(II) nitrate in acetonitrile. Conductometric data in acetonitrile shows C4PE behaves as a divalent cation salt with two nitrate ions undergoing primary and secondary dissociations. C4PE was used as a recognition element in the form of a composite with carbon paste as a selective electrode for the potentiometry sensing of nitrate in water samples. The electrode has a linear response to nitrate with a detection limit of 1×10−5molL−1 and exhibit a Nernstian slope (57.5±0.6mV/decade) between pH 3.6 and 9.6 with a fast response time less than 10s. The selectivity coefficient values indicate high selectivity for nitrate ions over various anions (NO3>NO2−>Cl−>Br−>I−>F−>CH3COO−>SO42−>IO3−>ClO4−). The electrodes were used over a period of 60 days with good reproducibility. The analytical usefulness of the proposed electrode has been evaluated by its application in the determination of nitrate ions in mineral and drinking water samples.

Novel potentiometric sensor for the determination of Cd2+ based on a new nano-composite

A novel ion selective carbon paste electrode for Cd2+ ions based on 2,2′-thio-bis[4-methyl(2-amino phenoxy) phenyl ether] (TBMAPPE) as an ionophore was prepared. The carbon paste was made based on a new nano-composite including multi-walled carbon nanotubes (MWCNTs), nanosilica and room-temperature ionic liquid, 1-Butyl-3-methylimidazolium hexafluorophosphate (BMIM-PF6). The constructed nano-composite electrode showed better sensitivity, selectivity, response time, response stability and lifetime in comparison with typical Cd2+ carbon paste sensor for the successful determination of Cd2+ ions in water and in waste water samples. The best performance for nano-composite sensor was obtained with an electrode composition of 18% TBMAPPE, 20% BMIM-PF6, 48% graphite powder, 10% MWCNT and 4% nanosilica. The new electrode exhibited a Nernstian response (29.95 ± 0.10 mV decade−1) toward Cd2+ ions in the range of 3.0 × 10−8 to 1.0 × 10−1 mol L−1 with a detection limit of 7.5 × 10−9 mol L−1. The potentiometric response of prepared sensor was independent of the pH of test solution in the pH range 3.0 to 5.5. It had a quick response with a response time of about 6 s. The proposed electrode showed fairly good selectivity over some alkali, alkaline earth, transition and heavy metal ions.

Anodic stripping voltammetry of silver(I) using a carbon paste electrode modified with multi-walled carbon nanotubes

We describe a silver(I)-selective carbon paste electrode modified with multi-walled carbon nanotubes and a silver-chelating Schiff base, and its electrochemical response to Ag(I). Effects of reduction potential and time, accumulation time, pH of the solution and the stripping medium were studied by differential pulse anodic stripping voltammetry and optimized. The findings resulted in a method for the determination of silver over a linear response range (from 0.5 to 235 ng mL−1) and with a detection limit as low as 0.08 ng mL−1. The sensor displays good repeatability (with the RSD of ± 2.75 % for 7 replicates) and was applied to the determination of Ag(I) in water samples and X-ray photographic films.

Chemically Modified Multiwalled Carbon Nanotubes as Efficient Material for Construction of New Al(III) Ion Selective Carbon Paste Electrode

A selective potentiometric ion-selective electrode for the determination of aluminium ion (Al3+) in aqueous solution based on incorporation of 2-((3-silylpropylimino) methyl) phenol in carbon paste matrices has been reported. For modification of the electrode response, the influence of multiwalled carbon nanotubes (MWCNTs) amount is investigated to improve conductivity and transduction of chemical signal to electrical signal. It is found that incorporation of MWCNTs at optimum composition of carbon paste (graphite powder: NaTPB: Nujol: carrier in the mass (mg) ratio of 150/9.0/40.0/100) significantly enhanced selectivity and sensitivity toward Al3+ ions over a wide concentration range of 1.0×10-7 to 5.0 × 10-2 mol L-1 with detection limit of 8.5 × 10-8 mol L-1 and a Nernstian slope of 19.7±0.2 mV per decade-1 of Al3+ concentration. The electrode response is independent of pH in the range of 3.5-7.0 with short the response time of about 5 s. The potentiometric selectivity coefficients of proposed Al3+ ion selective electrode calculated based on fixed interference method, separation solution method, and matched potential method show its moderate selectivity for Al3+ ion toward other metal ions. Finally, the proposed electrode is successfully used as an indicator for potentiometric determination of Al3+ in water samples.

A new potentiometric thiosalicylamide-functionalized polysiloxane carbon paste electrode for lead(II) determination

Thiosalicylamide-functionalized polysiloxane was prepared, characterized and utilized as the ionophore in construction of a lead(II)-selective carbon paste electrode. This new electrode exhibited a Nernstian response for lead ion over a wide concentration range of 4.3×10−6–1.0×10−2M with a detection limit of 8.7×10−7M within pH range 4.5–7.2 in a short response ∼5s. The electrode systematically showed satisfactory reproducibility and sensitivity as well as good selectivity for lead ion with respect to a large number of inorganic cations and anions. Finally, it was satisfactorily used as an indicator electrode in complexometric titration with EDTA and determination of lead(II) in miscellaneous samples such as water samples and commercial lipsticks.

Chemically Modified Multiwalled Carbon Nanotubes as Efficient Material for Construction of New Zinc (II) Ion Selective Carbon Paste Electrode

Chemically Modified Multiwalled Carbon Nanotubes as Efficient Material for Construction of New Zinc (II) Ion Selective Carbon Paste Electrode

Influence of Multiwalled Carbon Paste Nanotubes on Response of ${\rm Pb}^{2+}$ Ion Selective Carbon Paste Electrode Based on 2-((6-(5-Bromo-2-Hydroxybenzylideneamino) Hexylimino) Methyl)-4-Bromophenol as Novel Neutral Carrier

A new lead selective carbon paste electrode by incorporation of 2-((6-(5-bromo-2-hydroxybenzylideneamino) hexylimino) methyl)-4-bromophenol (BHBAHMBP) as new carrier in matrix of carbon paste has been reported. Influence of amount of carbon paste ingredints including sodium tetraphenylborate (NaTPB), BHBAHMBP, Nujol, graphite powder, amount of Multiwalled carbon nanotubes optimized and their value was set as carbon: (500/3.4/150/6.0/50 mg), respectively. At optimum values of variables these conditions the proposed electrode response toward Pb <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2+</sup> ion was linear in the range of 5.0×10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-7</sup> to 1.0×10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> mol L <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> with slope of 29.50 mV per decade <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> of Pb <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2+</sup> ion concentration and detection limit of 2.5×10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-7</sup> mol L <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> . The electrode response is independent of pH in the range of 2.7-4.0, while the response time of the electrode was ~ 40 s. The potentiometric selectivity coefficients and selectivity sequence of proposed Pb <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2+</sup> ion selective electrode has been evaluated using fixed interference method (FIM). The electrode successfully has been applied for potentiometric determination of pb <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2+</sup> ion content in various real samples and as indicator electrode in precipitation titration.