Polymer Modified Carbon Paste Electrode Research Articles

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.

A new Ag(I) inorganic polymer consisting of Ag(I)-Ag(I) bonds for electrochemical sensing of H2O2

A new silver(I) inorganic polymer, formulated as {[Ag4(H2ebidc) (NH3)4](H2O)2}n (H2ebidc = 2,2’-(ethane-1,2-diyl)bis(1H-imidazole-4,5-dicarboxylic acid), was synthesized and characterized by X-ray crystallography, elemental analysis and IR spectroscopy. The crystal analysis results showed that the four silver(I) ions were linked by the H2ebidc4− ligand to form a tetranuclear cluster subunit, and then a one-dimensional ring-to-ring chain was constructed through the Ag(I)-Ag(I) bonds between the cluster subunits. Electrochemical sensing performance of the Ag(I) inorganic polymer modified carbon paste electrode (CPE-Ag) for H2O2 was evaluated by chronoamperometry in 0.2 M phosphate buffer saline (PBS, pH = 6) at −0.2 V. The electrochemical H2O2 sensor CPE-Ag was found to lead to a linear response from 0.5 μM to 4.0 mM with a detection limit of 0.32 μM. Moreover, the sensor also revealed good anti-interference ability and stability. The above studies proved that Ag(I) inorganic polymers can be used as effective components of electrode materials for the electrochemical recognition of H2O2.

An ultrasensitive and selective electrochemical sensor for determination of estrone 3-sulfate sodium salt based on molecularly imprinted polymer modified carbon paste electrode.

A highly sensitive and selective electrochemical sensor based on carbon paste electrode (CPE) modified with molecularly imprinted polymers (MIPs) has been developed for the determination of estrone 3-sulfate sodium salt (ESS). MIPs were prepared in polar medium via bulk polymerization and characterized by scanning electron microscopy and infrared spectroscopy. Cyclic voltammetry was performed to the study preparation process and binding behavior of the MIP-modified CPE (MIP/CPE) toward ESS. The conditions for preparing MIPs and MIP/CPE as well as ESS detection were optimized. Under the optimal experimental conditions, the detection linear range for ESS is 4×10-12 to 6×10-9M with a limit of detection of 1.18×10-12M (S/N=3). In addition, the sensor exhibits high binding affinity toward ESS over its structural analogues with excellent repeatability and stability. The fabricated MIP/CPE was then successfully employed to detect ESS in pregnant mare urine (PMU) without any pretreatment, and the average recoveries were from 99.6 to 104.9% with relative standard deviation less than 3.0%. High-performance liquid chromatography was adopted as a reference to validate the established approach in detecting ESS and their results showed good agreement. The as-prepared sensor has high potential to be a decent tool for on-site determination of ESS in PMU in a fast and convenient manner. Graphical Abstract ᅟ.

A simple and sensitive sensor based on a molecularly imprinted polymer-modified carbon paste electrode for the determination of curcumin in foods

A highly sensitive and selective molecularly imprinted polymer-modified carbon paste electrode (MIP-CPE) was designed.

Electrochemical Determination of Moxifloxacin Hydrochloride Based on Molecularly Imprinted Polymer Modified Carbon Paste Electrode

Electrochemical Determination of Moxifloxacin Hydrochloride Based on Molecularly Imprinted Polymer Modified Carbon Paste Electrode

Voltammetric Determination of Uric Acid Based on Molecularly Imprinted Polymer Modified Carbon Paste Electrode

AbstractMolecularly imprinted polymer (MIP) for uric acid (UA) was synthesized by thermal polymerization using acrylic acid (AA) as functional monomer, ethylene glycol dimethacrylate (EGDMA) as cross linker and 2,2′‐azobis(2‐isobutyro) nitrile (AIBN) as initiator. The noncovalent interactions involved in four possible conformations of pre‐polymer complex were computationally studied by density functional theory. The hydrogen bond formation between UA and AA was confirmed by Fourier transform infrared (FTIR) spectrum of the MIP before extraction of UA. After extraction of the template, the molecularly imprinted polymer based carbon paste electrode (MIPCPE) was fabricated under optimized conditions. A significant enhancement in the electrocatalytic oxidation of UA was found at MIPCPE. The electrochemical behavior of sensor was investigated by cyclic voltammetry (CV) and differential pulse adsorptive stripping voltammetry (DPAdSV). The electrochemical impedance spectroscopy (EIS) studies revealed less charge transfer resistance (Rct) at MIPCPE than NIPCPE. Under optimized conditions, calibration curve was obtained with a linearity range of 0.5 µM to 100 µM and the limit of detection was 0.1 µM. The sensor showed good selectivity towards UA in the presence of interferents and was successfully applied for the determination of UA in spiked serum samples.

Low-Range Detection of the Phosphate Group by a Molecularly Imprinted Polymer-Modified Carbon Paste Electrode

A series of size-selective polymeric sensors for the phosphate group was designed and synthesized using the molecularly imprinted polymer (MIP) technique based on the noncovalent interaction of the template dipentyl phosphate with the functional monomer methacrylic acid. Very low-range specific electrochemical detection of phosphate molecules was performed by square wave voltammetry with a modified carbon paste electrode (CPE). Calibration curves were obtained within the linear range of 20-300 nmol L <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> for all modified CPEs, with the lowest detection limit determined as 8.82 nmol L <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> . Potential inorganic interferents, such as carbonate, nitrate and sulfate ions, were investigated and no signal disturbance was observed for relative concentrations 100 times higher than the phosphate concentration. Furthermore, the modified electrodes also showed good selectivity for phosphate molecules containing alkyl chains up to five carbon atoms. The selectivity study confirmed that imprinted sites were successfully synthesized and only structures that are the same size or smaller than those of the template molecule are selected by maximizing intermolecular interactions at the MIP binding site. Moreover, the sensors presented good stability, maintaining the same degree of selectivity for several months. These sensors were also applied in the determination of phosphate in a cola soft drink.

Electroanalytical determination of diazepam in tablet and human serum samples using a multiwalled carbon nanotube embedded molecularly imprinted polymer-modified carbon paste electrode

In this study a new MWCNT–MIP nanocomposite modified carbon paste electrode for determination of diazepam has been developed.

Tenoxicam’s Electro-Analytical Determination with a b-Cyclodextrin Modified-Electrode

An electrochemical study is presented of the analytical determination of the non-steroidal anti-inflammatory drug called tenoxicam. In this study the detection, quantification limit and sensibility obtained with different electrochemical techniques are presented, using a carbon paste electrode as working electrode, as well as the results obtained for the same study carried out with a b-cyclodetrin polymer-modified carbon paste electrode, which gave better analytic parameters for the determination, basically due to drug adsorption into the membrane of this electrode.

Voltammetric determination of rivastigmine in pharmaceutical and biological samples using molecularly imprinted polymer modified carbon paste electrode

Despite the increasing number of applications of molecularly imprinted polymers (MIPs) in analytical chemistry, the construction of a biomimetic voltammetric sensor remains still challenging. A new voltammetric sensor for rivastigmine (RIV) measurement is introduced. A RIV-selective molecularly imprinted polymer and a non-imprinted polymer (NIP) were synthesized in a non-covalent approach using methacrylic acid (MAA) as functional monomer and ethylene glycol dimethacrylate (EGDMA) as crosslinking monomer via a free radical polymerization and then were used for carbon paste electrode (CPE) preparation. The electrochemical behavior of the sensor toward RIV was investigated by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The MIP embedded in the CPE, functioned as a selective recognition element and a pre-concentrator agent for RIV determination. The MIP-CPE showed very high recognition ability in comparison to NIP-CPE. The complete removal of RIV from polymer was confirmed by FTIR and TGA. Some parameters affecting sensor response were optimized, and a calibration curve was then plotted. A linear range of 2.0–1000μmolL−1 was obtained. The detection limit of the sensor was calculated to be equal to 0.44μmolL−1. This sensor was used successfully for RIV determination in capsule and spiked serum and urine samples.

A Novel and Selective Methylene Blue Imprinted Polymer Modified Carbon Paste Electrode

AbstractIn this study, methylene blue (MB) imprinted microbeads were synthesized and characterized by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM).Differential pulse voltammetric responses of carbon paste electrodes modified with MB imprinted polymer were used to evaluate the adsorption and selectivity features of the polymer. For selectivity studies two basic dyestuffs (thionine blue and toluidine blue) which have similar structure to MB were chosen. Comparison of the voltammetric responses obtained with pure carbon paste and carbon paste modified with either imprinted or nonimprinted polymer electrodes revealed that MB imprinted polymer presented a higher selectivity to the template molecule MB in contrast to structurally similar molecules, thionine blue and toluidine blue.

Electroanalytical determination of sulfasalazine in pharmaceutical and biological samples using molecularly imprinted polymer modified carbon paste electrode

An electrochemical sensor for sulfasalazine determination based on molecularly imprinted polymer (MIP) as recognition element has been developed. A sulfasalazine selective MIP and a non-imprinted polymer (NIP) were synthesized and then incorporated in the carbon paste to prepare the modified carbon paste electrodes. Trace amount of sulfasalazine was determined by using differential pulse voltammetry method based on electrochemical reduction of sulfasalazine at the modified electrodes. The MIP based sensor showed high recognition ability of sulfasalazine in comparison with the NIP based sensor. The influence of experimental parameters affecting sensor response such as carbon paste composition, pH, incubation time, potential scan rate and potential amplitude were optimized. Under optimal conditions, the MIP based sensor exhibited good performance for sulfasalazine over the concentration range of 1.0×10−8 to 1.0×10−6molL−1 with a detection limit of 4.6×10−9molL−1 and sensitivity 1.11×107μALmol−1. The MIP based sensor was successfully applied to the determination of sulfasalazine in a commercial pharmaceutical formulation and human serum, offering feasibility and applicability of the sensor to the complex matrices.

A chemometrics approach for simultaneous determination of cyanazine and propazine based on a carbon paste electrode modified by a molecularly imprinted polymer

In a completely rational and designed approach, simultaneous determination of cyanazine and propazine in environmental and food samples was performed using a molecularly imprinted polymer modified carbon paste electrode (MIP-CPE) and partial least squares. The MIP-CPE designed is based on the theoretical studies functioned as a selective recognition element and pre-concentrator agent for cyanazine and propazine. Fractional factorial and central composite designs were performed to recognize, and subsequently optimize, the variables affecting the cathodic stripping voltammetric currents for the analytes. The important variables were identified to be accumulation potential with optimum values of -0.45 and -0.44 V and pH with optimum values of 2.40 and 2.34 for cyanazine and propazine, respectively. Exploration of the overall optimum conditions for simultaneous determination of cyanazine and propazine resulted in accumulation potential of -0.44 V and pH of 2.4. Dynamic linear ranges of 0.05-9.00 μmol L(-1) and 0.01-1.00 μmol L(-1) and detection limits of 0.010 and 0.001 μmol L(-1) were obtained for cyanazine and propazine, respectively. The results of the application of the proposed method on the simultaneous determination of cyanazine and propazine in foodstuffs and environmental samples were satisfactory.

Development of piroxicam sensor based on molecular imprinted polymer-modified carbon paste electrode

A new voltammetric sensor for piroxicam measurement is introduced. A piroxicam-selective molecularly imprinted polymer (MIP) and a non-imprinted polymer (NIP) were synthesized in a non-covalent approach using methacrylic acid (MAA) as functional monomer and ethylene glycol dimethacrylate (EGDMA) as cross-linking monomer via a free radical polymerization and then was used for carbon paste (CP) electrode preparation. The MIP, embedded in the carbon paste electrode, functioned as a selective recognition element and pre-concentrator agent for piroxicam determination. The prepared electrode was used for piroxicam measurement via a three-step procedure including analyte extraction in the electrode, electrode washing and electrochemical measurement of piroxicam. The MIP–CP electrode showed good recognition ability in comparison to NIP–CP. Some parameters affecting sensor response were optimized. Under optimum conditions the oxidation peak current was proportional to piroxicam concentration over the range 2–190 and 190–2500 nM. The detection limit was found to be 0.5 nM. This sensor has been successfully applied for the determination of piroxicam in pharmaceutical formulations and serum samples.

Electrogenerated chemiluminescence of ruthenium complex immobilized in a highly cross‐linked polymer and its analytical applications

Electrogenerated chemiluminescence (ECL) of a ruthenium complex polymer modified carbon paste electrode and its analytical applications were investigated. The ruthenium complex polymer was prepared using bis(2,2-bipyridine) (4,4-dicarboxy-2,2-bipyridine) ruthenium(II). The ECL behaviours of ruthenium complex polymer modified carbon paste electrode were investigated in the absence and presence of tripropylamine (TPA). The modified carbon paste electrode exhibited long-term stability and fine reproducibility. The ECL intensity of the modified carbon paste electrode was linear with the concentration of TPA in the range 2.0 x 10(-6)-3.8 x 10(-3) mol/L, with a detection limit (S:N = 3) of 6 x 10(-7) mol/L. It was also found that raceanisodamine could enhance the ECL intensity of the modified electrode. The ECL intensity of the modified carbon paste electrode was linear with the concentration of raceanisodamine in the range 1.1 x 10(-5)-6.0 x 10(-4) mol/L, with a detection limit (S:N = 3) of 6 x 10(-6) mol/L. This work demonstrates that the entrapment of ruthenium complex in a highly cross-linked polymer is a promising approach to construct an ECL modified electrode with long-term stability and fine reproducibility. The modified electrode designed has a potential application in the ECL detector.

Rapidly renewable and reproducible electropolymerized surface at a monomer modified carbon paste electrode

A novel method of generating a rapidly renewable and reproducible polymer coated electrode surface is proposed. This involves in situ electropolymerization at a monomer modified carbon paste electrode. A carbon paste electrode bulk modified with 2-methyl-8-hydroxyquinoline was used to demonstrate this approach. The polymer modified carbon paste electrode obtained by electropolymerization was found to be useful for trace determination of Cu(II), involving preconcentration and anodic stripping procedures. It was also shown that the polymer coated electrode surface could be renewed quickly and reproducibly after each determination. An optimized procedure was developed subsequently for the determination of Cu(II) and this was employed for the determination of Cu(II) in a certified water quality control sample. Although the proposed method was demonstrated for Cu(II) determination, in principle, it can be more generally useful in applications involving polymer modified electrodes.