Modified Carbon Paste Electrode Research Articles

Synthesis of nanozeolites type A and X from quartz-rich Cameroonian kaolin: application to the modification of carbon paste electrode for acetaminophen and epinine electrochemical sensing

Synthesis of nanozeolites type A and X from quartz-rich Cameroonian kaolin: application to the modification of carbon paste electrode for acetaminophen and epinine electrochemical sensing

Carbendazim trace analysis in different samples by using nanostructured modified carbon paste electrode as voltametric sensor.

Carbendazim (CBZ) as a fungicide is widely used to control fungal diseases in agriculture, veterinary medicine, and forestry. In this study, molecularly imprinted nano-size polymer was synthesized and then combined with multiwalled carbon nanotubes to be used as modifiers for carbon paste electrode to detect carbendazim in water, fruit, agricultural wastewater, and urine samples by using the square-wave technique. Some common ions and pesticides were investigated as interferences in analyte, to study the sensitivity and selectivity of the modified carbon paste electrode for carbendazim. The combination of molecular imprinted polymer and multiwalled carbon nanotubes showed a significant increase in peak current in electrocatalytic activity on electrochemical detection of the carbendazim. The linear range of 1 × 10-10 to 5 × 10-8 molL-1 was investigated. The lower detection limit was determined to be 0.2 × 10-10 molL-1, and the relative standard deviation for the target molecule analysis was 2.07%. The result reveals that the modified carbon paste sensor with Multi walled Carbon Nanotubes (MWCNTs) and Molecular Imprinted Polymer (MIPs) can be used easily, without preparation steps that have high selectivity and sensitivity to determine carbendazim in water, fruit, agricultural wastewater, and urine samples.

Poly DY 11/Zn/CuO modified electrochemical sensor for the detection of catechol and hydroquinone: A voltammetric study

In the present work, Zn doped CuO nanoparticles (Zn/CuO Npcs) was synthesized by co-precipitation method for the fabrication of electrode towards the detection of Catechol (CA) and Hydroquinone (HY). The particle size and surface morphology of Zn/CuO Npcs was characterized by X-ray diffraction technique (XRD) and Scanning electron microscopy (SEM). Further cyclic voltammetric technique was used for the electropolymerization of Direct Yellow 11 (DY 11) on the surface of Zn doped CuO modified carbon paste electrode (MCPE) and applied for the determination of CA and HY at optimum pH 7.4. After the modification, the PolyDY11/Zn/CuO electrode exhibits very stable and sensitive current responses towards the CA and HY. The various parameters like scan rate, pH and concentration of both CA and HY were studied. Simultaneous determination of CA and HY in presence of Resorcinol (RE) was investigated by using cyclic voltammetry, Selectivity study of CA and HY was studied using the differential pulse voltametric technique. The fabricated electrode exhibits adsorption controlled and limit of detection (LOD) calculated for CA and HY in range (10–90 μM) was found to be CA(6 μM) and HY(7 μM) respectively, The real sample analysis in tap water showed better recovery between 90 and 96% for CA and 90–94% for HY respectively.

Carbon Paste Electrode Modified by Dibenzo-18-crown-6 for the Determination of Paracetamol Using Differential Pulse Voltammetry Technique

The fabrication, optimization and validation of measurement using a modified carbon paste electrode (CPE) with dibenzo-18-crown-6 were carried out for the determination of paracetamol in commercial products. The pH, dibenzo-18-crown-6 concentration in carbon paste, and scan rate parameters were optimized. Validation of the measurement was observed from linear concentration range, LoD, LoQ, precision, and percentage of the recovery. The result showed that the optimum pH was at 2, the optimum concentration of dibenzo-18-crown-6 in carbon paste was 0.6%, optimum scan rates were 35 mV/s for CPE, and increased to 50 mV/s using modified CPE. The linear concentration range for CPE was obtained at 10-300 µM with LoD and LoQ of 28.88 and 96.28 µM, respectively. Meanwhile, CPE modified with dibenzo-18-crown-6 gave wider linear concentration range at 1–700 µM with LoD and LoQ of 52.36 and 174.53 µM, respectively. The CPE and modified CPE had good precision, with Horwitz ratio values of less than two. The percentage of recovery for two samples with three replicates measurements was obtained (89.81 ± 1.38)% and (108.02 ± 0.42)% for samples A and B, respectively. Dibenzo-18-crown-6 modified CPE was used for the determination of paracetamol in both samples yielding 97–98% compared with the paracetamol composition on its labels.

Electrochemical studies of catechol and hydroquinone at poly(nigrosine) modified carbon paste electrode: a cyclic voltammetric study

Electrochemical studies of catechol and hydroquinone at poly(nigrosine) modified carbon paste electrode: a cyclic voltammetric study

Polymer modified carbon paste electrode for the electrochemical analysis of Tartrazine

The tartrazine (TZ) analysis is useful for both environment and health. In the present work, a electrode was fabricated for the determination of TZ by electro-polymerization of niacin on the electrode surface. For this purpose, fabrication of poly (niacin) modified carbon paste electrode (PNMCPE) was done using phosphate buffer solution (PBS) of 0.2 M at pH 7.0. Cyclic voltammetry (CV), Electrochemical impedance spectroscopy (EIS), and Field emission scanning electron microscopy (FE-SEM) methods were used to study the electrochemical responce and surface morphology of the PNMCPE and bare carbon paste electrode (BCPE) materials. Various parameters such as effect of scan rate, active surface area, material conductivity and resistivity, detection limit, and effect of pH were analyzed in 0.6 to 1.1 V of potential range using 0.2 M PBS as a supporting electrolyte. The electrochemical oxidation of TZ was analyzed in presence of different interfering ions and organic compounds on the electrode surface. The obtained values of limit of detection (LOD) and limit of quantification (LOQ) for TZ are found to be 0.1246 µM and 0.4155 µM, respectively. Furthermore, the fabricated electrode was used to analyze TZ in food sample to confirm its analytical application.

Designing an electrochemical biosensor based on tyrosinase for highly sensitive and rapid detection of bisphenol A and its derivatives

Bisphenol A (BPA) is a monomer commonly used in the production of epoxy resins, plastic bottles and dental filling materials. Due to its chemical structure, BPA and its derivates show activity similar to the endocrine hormones. It can bind to estrogen receptors and cause neurological disturbances, even at low doses. Therefore, it is important to determine BPA and its derivatives quickly and sensitively at low concentrations. In this study, a single amperometric tyrosinase enzyme biosensor was designed for the determination of the amount of BPA, bisphenol F (BPF) and bisphenol S (BPS) monomers. Tyrosinase was immobilized onto a modified carbon paste electrode by cross-linking with glutaraldehyde. The amount of BPA (BPS and BPF) was determined directly on the reduction of quinone compound released as a result of the enzymatic reaction at ?0.15V. Km(app) value of the designed biosensor for BPA was found 0.00067 ?M, the linear operating range was 0.001?0.005 ?M (a) and 0.03?0.1 ?M (b) and the lower detection limit was found 1 nM for each monomer. It is clear that designed biosensor enable the fast, efficient and precise determination of BPA and its derivatives released from materials used in dental materials.

Electrochemical determination of aripiprazole based on aluminium oxide nanoparticles modified carbon paste electrode.

The electrochemical oxidation of aripiprazole was explored at a carbon paste electrode modified with aluminium oxide nanoparticles by cyclic voltammetry and square-wave anodic adsorptive stripping voltammetry. Experimental parameters such as carbon paste composition, scan rate, buffer pH, accumulation time, and accumulation potential were optimized in order to obtain high analytical performance. The incorporation of aluminium oxide nanoparticles into the carbon paste matrix enhanced the effective surface area of the carbon paste electrode and improved the sensitivity. On the aluminium oxide nanoparticles modified carbon paste electrode, aripiprazole exhibited an irreversible anodic peak at +1.17 V in pH 1.8 BR buffer solution. Under optimum conditions, the peak current exhibited a linear dependence with aripiprazole concentration between 0.03 and 8.0 μM with a detection limit of 0.006 μM. The analytical applicability of the voltammetric method was evaluated by quantification of ARP in human serum samples and pharmaceutical formulations.

Highly selective square wave voltammetric determination of gallic acid in groundnut and tea samples using glycine(2-aminoethanoic acid) modified carbon paste electrode

Phenolic compounds are well-known as antioxidants including many other important bioactive agents that have long been interested due to their benefits for human health, curing and preventing many diseases. Gallic acid (GA), is a naturally occurring most abundant phenolic acid compound found in groundnut, honey, mango, tea, wine, and various medicinal plants. Different techniques have been used for determination of GA. Electrochemical technique is of the best methods. A sensor with improved sensitivity for GA determination in real samples is developed. This work presents preparation of glycine modified carbon paste electrode (GMCPE) for square wave voltammetry determination of GA in groundnut and tea samples. Cyclic voltammetry and Electrochemical impedance spectroscopy results evidenced that modification of the surface of CPE by glycin improves the surface area and conductivity of the electrode. The appearance of an irreversible oxidative peak for GA with much reduced oxidative potential and about four folds current enhancement at GMCPE than the bare CPE showed the catalytic property of the modifier towards oxidation of GA. Under optimized conditions, SWV current response of GMCPE showed a linear dependence on the concentration of GA in the range 1.0 ​× ​10−6 – 2.0 ​× ​10−4 ​M, with LoD and LoQ 1.53 ​× ​10−8 ​M and 5.1 ​× ​10−8 ​M, respectively. Spike recovery results in groundnut and tea samples in the range 89.75–98.98% and 92.15–97.10%, respectively. Interference effect in the presence of selected potential interferents at their various levels with associated errors under 4.63% showed no interference on the current response of GA. The stability of the modifier with analysis time validated the applicability of the method for the determination of GA in real samples. Relative to previously reported works wider linear dynamic range, low LoD, high accuracy and selectivity make the present developed method an excellent candidate for determination of GA in real samples.

Synergetic effects of a poly-tartrazine/CTAB modified carbon paste electrode sensor towards simultaneous and interference-free determination of benzenediol isomers

Simultaneous and selective detection of dihydroxy benzene isomers by the synergistic effect of CTAB and tartrazine on a carbon paste electrode (poly-TZ/CTAB/MCPE) sensor by CV and DPV techniques.

Electrochemical sensor based on amine- and thiol-modified multi-walled carbon nanotubes for sensitive and selective determination of uranyl ions in real water samples.

Novel selective and sensitive electrochemical sensors based on the modification of a carbon paste electrode (CPE) with novel amine- and thiol-functionalized multi-walled carbon nanotubes (MWCNT) have been developed for the detection and monitoring of uranyl ions in different real water samples. Multiwalled carbon nanotubes were grafted with 2-aminothiazole (AT/MWCNT) and melamine thiourea (MT/MWCNT) via an amidation reaction in the presence of dicyclohexyl carbodiimide (DCC) as a coupling agent. This modification for multiwalled carbon nanotubes has never been reported before. The amine and thiol groups were considered to be promising functional groups due to their high affinity toward coordination with uranyl ions. The modified multi-walled carbon nanotubes were characterized using different analytical techniques including FTIR, SEM, XPS, and elemental analysis. Subsequently, 10 wt% MT/MWCNT was mixed with 60 wt% graphite powder in the presence of 30 wt% paraffin oil to obtain a modified carbon paste electrode (MT/MWCNT/CPE). The electrochemical behavior and applications of the prepared sensors were examined using cyclic voltammetry, differential pulse anodic stripping voltammetry, and electrochemical impedance spectroscopy. The MT/MWCNT/CPE sensor exhibited a good linearity for UO22+ in the concentration range of 5.0 × 10-3 to 1.0 × 10-10 mol L-1 with low limits of detection (LOD = 2.1 × 10-11 mol L-1) and quantification (LOQ = 7 × 10-11 mol L-1). In addition, high precision (RSD = 2.7%), good reproducibility (RSD = 2.1%), and high stability (six weeks) were displayed. Finally, MT-MWCNT@CPE was successfully utilized to measure the uranyl ions in an actual water sample with excellent recoveries (97.8-99.3%). These results demonstrate that MT-MWCNT@CPE possesses appropriate accuracy and is appropriate for environmental applications.

Polyaniline-poly (methylene blue) nano-rod composites as an electrochemical sensor for sensitive determination of ascorbic acid

Polyaniline-poly (methylene blue) nano-rod composite has been prepared by a chemical oxidative polymerization method. The PANI-PMB composite was characterized by scanning electron microscopy, spectrophotometry, Fourier transforms infrared spectrometry, and X-ray diffraction. The electrochemical performance of the PANI-PMB composite was studied by electrochemical impedance spectroscopy, cyclic voltammetry, and differential pulse voltammetry. The prepared nanocomposite was applied for the electrochemical sensing of ascorbic acid. The results show that the PANI-PMB modified carbon paste electrode (PANI-PMB/CPE) had better catalytic activity to the electrochemical oxidation of ascorbic acid compared with PANI/CPE, PMB/CPE and CPE, which was due to the fast electron transfer efficiency of the PANI-PMB composite. Under the optimized experimental conditions, the differential pulse voltammetric peak current was linear with the ascorbic acid concentration in the range from 4 to 110 μM with a detection limit of 1.3 μM. Furthermore, the proposed method has been applied for the determination of ascorbic acid content in vitamin C tablets.

Luminol electrochemiluminescence by combining cathodic reduction and anodic oxidation at regenerable cobalt phthalocyanine modified carbon paste electrode for dopamine detection

Luminol electrochemiluminescence (ECL) generated by coupling the cathodic reduction of dissolved oxygen with subsequent anodic oxidation of luminol at cobalt phthalocyanine modified carbon paste electrode (CoPc-CPE) has been reported for the first time. The luminol ECL generated at CoPc-CPE by scanning potential from −0.3 V to 1.0 V is 250 times greater than that generated by scanning potential from 0 V to 1.0 V. Moreover, the CoPc-CPE exhibited about 16-fold stronger ECL than the bare carbon paste electrode because of the excellent electrocatalytic activity of CoPc. The developed ECL system was successfully applied to the efficient sensing of dopamine with a fine linear range from 0.5 µM to 50 µM and a detection limit of 8.8 nM at a signal-to-noise ratio of 3 based on the quenching effect of dopamine. The CoPc-CPE exhibits excellent long-term stability during 65 days of storage in the ambient environment.

Electrochemical Detection of Olivetol Based on Poly(L-Serine) Film Layered Copper Oxide Modified Carbon Paste Electrode (p-L-Serine/CuO/CPE)

Olivetol is an important polyphenol compound and intermediate in the synthesis of cannabinoids possessing many types of biological activities. A facile electrochemical sensor for olivetol was fabricated based on p-L-serine, and copper oxide (CuO) nanoparticles modified carbon paste electrode (p-L-serine/CuO/CPE). The proposed p-L-serine/CuO/CPE was applied to the electrochemical detection of olivetol by cyclic voltammetry (CV) and differential pulse voltammetric (DPV). Through the characterizations of materials and modified electrodes, the p-L-serine/CuO/CPE exhibited enhanced electrochemical signals for olivetol compared to bare CPE and CuO/CPE in both CV and DPV methods. Under the optimized conditions, the proposed p-L-serine/CuO/CPE showed a good quantitative analysis ability and a wide analysis range from 20 to 100 μmol L-1 of olivetol with a limit of detection of 1.04 μmol L-1. Based on the reproducibility, repeatability, and stability exhibited by this fabricated sensor and the cheap and accessible raw materials, the p-L-serine/CuO/CPE became a novel determination choice for olivetol in the electrochemical method with the advantages of being cost-effective and convenient.

ZnO interrelated graphene matrix-based sensors for quercetin

An electrochemical study of quercetin (QUR) was carried out voltammetrically using graphene (Gr) and zinc oxide nanoparticles (ZnO) modified carbon paste electrodes (CPE). The effect of phosphate buffer solution (0.2 M PBS) of various pH was tested and we found that pH 6.0 was optimum. The electrochemical analysis of QUR involves a redox-coupled reaction with one oxidation peak at 0.356 V and a reduction peak at 0.324 V with a peak strength of 1.05 μA and 0.413 μA, respectively. The peak current obtained at the modified electrode was higher than the bare CPE, indicating the electrocatalytic behavior of the modifier. Surface characterization of Gr-ZnO/CPE was evaluated using X-ray diffraction (XRD) studies, field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and Energy dispersive X-ray spectroscope (EDS). Sweep rate investigation provided knowledge about reaction mechanisms involving transferring an equal number of electrons and protons. The electrochemical process was governed by adsorption. The limit of detection (LOD) was computed to be 18.0 nM. The developed electrode material was utilized to determine QUR in real samples, which exhibited excellent recovery, demonstrating the utility of the proposed electrode.

Electrocatalytic Performance of Nickel Hydroxide-Decorated Microporous Nanozeolite Beta-Modified Carbon Paste Electrode for Formaldehyde Oxidation

In this paper, aluminosilicate nanozeolite beta has been prepared and described using X-ray diffraction (XRD), nitrogen sorption isotherm, Fourier transform infrared (FT-IR), transmission electron micrograph (TEM), and field emission scanning electronic microscopy (FESEM) techniques; TEM image demonstrated semispherical particles with dimensions under 50 nm. The BET surface area, total pore volume, and pore diameter of it were attained to be 321 m2 g−1, 0.053 cm3 g−1, and 1.22 nm, respectively. The modified carbon paste electrode by aluminosilicate nanozeolite beta and nickel hydroxide (Ni(OH)2-Beta/CPE) was applied for formaldehyde (HCHO) electrocatalytic oxidation. The obtained results specify that Ni(OH)2-Beta/CPE demonstrates worthy electrocatalytic activity for oxidation of HCHO due to mesoporous construction and the great surface area of nanozeolite. The electron-transfer coefficient, catalytic rate constant, and diffusion coefficient are found to be 0.69, 2.08 × 106 cm3 mol−1 s−1, and 4.4 × 10−7 cm2 s−1, respectively. The Ni(OH)2-Beta/CPE exhibited low background current, simplicity of surface renewal, good reproducibility, and stability and also displayed high stability up to 300 cycles and 3000 s without an important loss in the current density. This modified electrode has better poisoning tolerance capability than bare CPE for HCHO electrocatalytic oxidation and is a higher device for the long term accomplishment.

Electrochemical monitoring of 4-chlorophenol as a water pollutant via carbon paste electrode amplified with Fe3O4 incorporated cellulose nanofibers (CNF)

A crucial problem that needs to be resolved is the sensitive and selective monitoring of chlorophenol compounds, especifically 4-chlorophenol (4-CP), one of the most frequently used organic industrial chemicals. In light of this, the goal of this study was to synthesize Fe3O4 incorporated cellulose nanofiber composite (Fe3O4/CNF) as an amplifier in the development of a modified carbon paste electrode (CPE) for 4-CP detection. Transmission electron microscopy (TEM) was used to evaluate the morphology of the synthesized nanocatalyst, while differential pulse voltammetry (DPV), electrochemical impedance spectroscopy (EIS), and linear sweep voltammetry (LSV) techniques were implemented to illuminate the electrochemical characteristics of the fabricated sensor. The ultimate electrochemical sensor (Fe3O4/CNF/CPE) was used as a potent electrochemical sensor for monitoring 4-CP in the concentration range of 1.0 nM–170 μM with a limit of detection value of 0.5 nM. As a result of optimization studies, 8.0 mg Fe3O4/CNF was found to be the ideal catalyst concentration, whereas pH = 6.0 was chosen as the ideal pH. The 4-CP's oxidation current was found to be over 1.67 times greater at ideal operating conditions than it was at the surface of bare CPE, and its oxidation potential decreased by about 120 mV. By using the standard addition procedure on samples of drinking water and wastewater, the suggested capability of Fe3O4/CNF/CPE to detect 4-CP was further investigated. The recovery range was found to be 98.52–103.66%. This study paves the way for the customization of advanced nanostructure for the application in electrochemical sensors resulting in beneficial environmental impact and enhancing human health.

Electrochemical sensor based on a poly-murexide modified carbon paste electrode for determination of fluoroquinolone antibiotic ciprofloxacin

Electrochemical sensor based on a poly-murexide modified carbon paste electrode for determination of fluoroquinolone antibiotic ciprofloxacin

Electro-catalytic determination of l-Cysteine using multi walled carbon nanotubes-Co3O4 nanocomposite/benzoylferrocene/ionic liquid modified carbon paste electrode

We attempted to develop a new electrochemical sensing platform via the modification of carbon paste electrode using multi-walled carbon nanotubes-Co3O4 nanocomoisite/benzoyl ferrocene/ionic liquid (MWCNTs-Co3O4/BF/IL/CPE), with the aim of detecting l-Cysteine (l-Cys) analyte. A facile hydrothermal protocol was fulfilled to construct the nano-composite, followed by characterizing via Energy-dispersive X-ray spectroscopy (EDS), field emission scanning electron microscopy (FESEM), Fourier transform-infrared spectroscopy (FT-IR) and X-ray diffraction (XRD). The electrocatalytic behavior of l-Cys was explored on the modified electrode surface through cyclic voltammetry (CV), chronoamperometry, and differential pulse voltammetry (DPV). The findings from the cyclic voltammetry highlighted an excellent catalytic activity of proposed MWCNTs-Co3O4/BF/IL/CPE towards the l-Cys oxidation in phosphate buffer solution (pH = 7.0) when comparing with other electrodes, owing to synergistic influence of fused ferrocene-derivative, ionic liquid and nanocomposite. The as-develop sensor had a narrow limit of detection of 0.04 ± 0.001 μM and a broad linear dynamic range of 0.1 μM to 100.0 μM. Notably, the MWCNTs-Co3O4/BF/IL/CPE exhibits good sensitivity of 0.1449 µA·µM−1. The practical applicability of our sensor was confirmed by sensing the l-Cys in real samples, possessing satisfactory recoveries (97.8 %-104.3 %).

Synthesis and Application of Domestic Glassy Carbon TiO2 Nanocomposite for Electrocatalytic Triclosan Detection

Nanoparticles of TiO2 are suitable for many catalytic and photocatalytic applications due to their extraordinary properties such as superhydrophobicity, semiconductivity, electron-rich, and environmental compatibility. The main crystalline phases of TiO2, anatase, and rutile possess different crystal structures, crystallinity, crystalline sizes, and specific surface areas, and these characteristics directly affect the catalytic performance of TiO2. In the present study, domestic carbon material enhanced with TiO2 nanoparticles was synthesized and used for the construction of a modified carbon paste electrode. The electrocatalytic activity of the modified electrodes was investigated depending on the TiO2 crystalline phases in the electrode material. Furthermore, the obtained working electrode was utilized for triclosan detection. Under optimized experimental conditions, the developed electrode showed a submicromolar triclosan detection limit of 0.07 µM and a wide linear range of 0.1 to 15 µM. The relative standard deviations for repeatability and reproducibility were lower than 4.1%, and with satisfactory selectivity, the proposed system was successfully applied to triclosan monitoring in groundwater. All these results confirm that the sustainable production of new and domestically prepared materials is of great benefit in the field of electrocatalysis and that the morphology of such produced materials is strongly related to their catalytic properties.