Film Modified Carbon Paste Electrode Research Articles

A novel sensor based on calcium oxide fabricated from eggshell waste conjugated with L- serine polymer film modified carbon paste electrode for sensitive detection of moxifloxacin in human serum and pharmaceutical constituents

A novel sensor based on calcium oxide fabricated from eggshell waste conjugated with L- serine polymer film modified carbon paste electrode for sensitive detection of moxifloxacin in human serum and pharmaceutical constituents

A Novel Sensor Based on Calcium Oxide Fabricated from Eggshell Waste Conjugated with L- Serine Polymer Film Modified Carbon Paste Electrode for Sensitive Detection of Moxifloxacin in Human Serum and Pharmaceutical Constituents

A Novel Sensor Based on Calcium Oxide Fabricated from Eggshell Waste Conjugated with L- Serine Polymer Film Modified Carbon Paste Electrode for Sensitive Detection of Moxifloxacin in Human Serum and Pharmaceutical Constituents

Preparation and Assessment of a Polysafranin/Multiwall Carbon Nanotube-Nafion Hybrid Film–Modified Carbon Paste Electrode and Its Performance as an Easy Sensing Probe for H2O2 and Cu2+

A polysafranin/multiwall carbon nanotube-Nafion hybrid film was prepared by electropolymerizing safranin on the surface of a MWCNT-Naf/CPE. The modified electrode was evaluated as an electrochemical sensor for hydrogen peroxide (H2O2) and Cu2+ in the presence of H2O2, in 0.1 M Tris buffer (pH 6.0) using cyclic and differential pulse voltammetric methods. The electrode showed a pair of well-defined and quasi-reversible redox peaks with formal potential (E°΄) = 0.290 ± 0.005 V versus Ag/AgCl corresponding to the polysafranin redox couples. The effects of the experimental variables on the electrode behavior regarding polymerization conditions, electrolyte pH, and MWCNT concentration were investigated to obtain optimum experimental conditions. The investigation of differential pulse voltammetric results showed that the polysafranin film at the modified electrode surface acts as an effective catalyst for H2O2 r and Cu2+ reduction in the presence of H2O2. Under optimum conditions, the modified electrode exhibited a linear dynamic range of 4.5–23.0 mM and a sensitivity of 17.4 ± 0.4 μA mM-1 cm‑2 toward H2O2 with a detection limit of 0.6 mM (3Sbl/m). In the presence of 17.0 mM H2O2, the electrode showed a linear response range of 1.0–80.0 μM and a sensitivity of 7.6 ± 0.2 μA μM‑1 cm‑2, with a detection limit of 0.1 μM (3Sbl/m) for Cu2+. In the next step, using differential pulse voltammetry, the response of the electrode to Cu2+ was studied in the presence of interfering metal ions that can promote Fenton’s reaction. The results showed that Fe2+, Co2+, and Al3+ produce interference at more than 5-, 2- and 10-fold ratios ([cation]/[Cu2+]) respectively.

Anodic stripping voltammetric measurement of trace cadmium at antimony film modified sodium montmorillonite doped carbon paste electrode

In this work, a simple and reliable electrochemical method for the determination of cadmium using an antimony film modified sodium montmorillonite (NaMM) doped carbon paste electrode (Sb/NaMM-CPE) was described. Due to the strong cation exchange ability and adsorptive characteristics of NaMM and excellent electroanalytical performance of the antimony film, the new electrode significantly enhanced the sensitivity for detection of Cd(II) and exhibited superior performance in comparison with the bare carbon paste electrode, antimony film modified carbon paste electrode (Sb/CPE), and NaMM modified carbon paste electrode (NaMM-CPE). Some parameters such as the composition of the paste, pH of the measure solution, the Sb(III) concentration, deposition time, and deposition potential that influenced the response of cadmium were investigated and the procedure was optimized for cadmium determination. This electrode, combined with square-wave anodic stripping voltammetry, displayed excellent linear behavior in the examined concentration range of 4.0–150.0μgL−1 Cd(II) (R2=0.998) with a detection limit of 0.25μgL−1. The Sb/NaMM-CPE was successfully applied to the determination of cadmium ion in tap water sample.

Voltammetric resolution of catechol and hydroquinone at eosin Y film modified carbon paste electrode

A sensitive, selective and reproducible electrochemical method was developed for the electroanalysis of catechol (CC) and hydroquinone (HQ) using eosin Y film modified carbon paste electrode (eosin Y/CPE). The modified electrode lowers the over potential and favours the oxidation of CC and HQ. The effect of scan rate and concentration studies reveals that the electrode process is controlled by the adsorption of an analytes. The simultaneous separation of CC and HQ was achieved in a binary mixture by cyclic voltammetric (CV) and differential pulse voltammetric (DPV) techniques. The separation of the oxidation peak potentials for CC–HQ was about 0.114V and 0.118V by CV and DPV techniques respectively. This peak differences were large enough to determine CC and HQ individually or simultaneously. The lower limit of detection of CC was 0.27μM and 0.79μM for HQ. The eosin Y/CPE was achieved the voltammetric separation of the dihydroxy benzene isomers in a binary mixture by CV technique; this work provides a simple and easy approach for the modification of the bare carbon paste electrode.

Carbon paste electrode modified with duplex molecularly imprinted polymer hybrid film for metronidazole detection

A novel electrochemical sensor based on duplex molecularly imprinted polymer (DMIP) hybrid film modified carbon paste electrode (CPE) has been developed for highly sensitive and selective determination of metronidazole (MNZ). A conductive poly(anilinomethyltriethoxysilane) film is firstly electrodeposited on the surface of a CPE, and then a molecularly imprinted polysiloxane (MIPS) membrane is covalently covered on the film via sol-gel process. The as-constructed DMIP hybrid film, combining the advantages of MIPS and conducting MIP, can make feasible the direct and efficient signal transformation between the target analyte and the transducer, as well as enhance the imprinting recognition capability, mass transfer efficiency and the detection sensitivity. Under optimized conditions, the reduction peak currents of MNZ are linear to MNZ concentrations in the range from 4.0×10−7 to 2.0×10−4 molL−1 with a detection limit of 9.1×10−8molL−1. The RSD values vary from 2.9% to 4.7% for intra-day and from 3.4% to 4.2% for inter-day precision. The DMIP-based sensor has been successfully applied for the determination of MNZ in biological and pharmaceutical samples. The accuracy and reliability of the method is further confirmed by high performance liquid chromatography.

SDS/poly(alanine) Modified Carbon Paste Electrode based Voltammetric Sensors for the Detection of Norfloxacin

Electrochemical oxidation of norfloxacin (NX) at SDS/poly(alanine) film-modified carbon paste electrode (SPAMCPE) was studied by voltammetric technique in 0.2 M acetate buffer solution at pH 4.2. The modified electrode exhibited strong promoting effect and stability towards the detection of norfloxacin. From the studies of scan rate effect the overall electrode process was found to be adsorption controlled. The concentration effect reveals that the detection limit and quantification limit of norfloxacin were 6.6810-8 M and 2.2270-7 M respectively. The effect of pH suggested that equal number of protons and electrons were involved in the electrochemical oxidation of norfloxacin. The presence of SDS on the poly(alanine)film-modified carbon paste electrode showed excellent electrocatalytic effect towards the detection of norfloxacin.

Preparation and Characterization of Carbon Paste Electrode Modified by Poly(1,8-diaminonaphthalene) and Nickel Ions Particles: Application to Electrocatalytic Oxidation of Methanol

In this work, we propose an electrochemical application of Poly(1,8-Diaminonaphthalene) and Nickel ions Particles (NiPs) modified carbon paste electrode (CPE) to electrocatalytic oxidation of methanol for direct methanol fuel cells (DMFCs). The electrochemical characterization of the film modified carbon paste electrode (CPE/PDAN)/NiPs) has been done in alkaline medium. It was found that it exhibits an interesting redox behavior of nickel particles. The dispersion, morphology, conductivity and structure of the modified electrode are characterized by scanning electron microscopy (SEM), cyclic voltammetry (CV), and electrochemical impedance spectra (EIS).

Electrochemical Investigation of Uric acid at Poly (Isoniazid) film Modified Carbon paste Electrode

A voltammetric determination of Uric acid (UA) has been studied on electropolymerisation of Isoniazid modified carbon paste electrode. Voltammetric behavior of Uric acid (UA) on the poly (Isoniazid) modified carbon paste electrode was investigated with electrochemical parameters of cyclic voltammetry. The variation of P H ,Scan rate, Concentration of Uric acid (UA) has been studied. In optimal conditions, the oxidation peak current of UA on the poly (Isoniazid) modified carbon paste electrode was enhanced greatly indicating high sensitivity. The low detection limit (LOD) and low detection quantity (LOQ) of UA has been found to be 1.173 µM and 3.910 µM with a correlation coefficient of 0.99442. The practical application of the modified electrode in the determination of UA has good selectivity and high sensitivity.

A sensor based on incorporating Ni2+ into ZnO nanoparticles-multi wall carbon nanotubes-poly methyl metacrylat nanocomposite film modified carbon paste electrode for determination of carbohydrates

The ZnO nanoparticles (ZnONPs) were synthesized with gelatin as stabilizer via the sol-gel method and were characterized by transmission electron microscope (TEM), scanning electron microscopy (SEM) and X-ray diffraction (XRD). An electrochemical sensor based on ZnO nanoparticles-multi wall carbon nanotubes-poly methyl metacrylat (ZnONPs-MWCNT-PMMA) composite film was developed by incorporating Ni2+ into the ZnONPs-MWCNT-PMMA film modified carbon paste electrode (Ni2+/ZnONPs-MWCNT-PMMA/CPE). The electrochemical activity of Ni2+/ZnONPs-MWCNT-PMMA/CPE was illustrated in 0.10 M NaOH using cyclic voltammetry. The Ni2+/ZnONPs-MWCNT-PMMA/CPE exhibits the characteristic of improved reversibility and enhanced current responses of the Ni(III)/Ni(II) couple. Ni2+/ZnONPs-MWCNT-PMMA/CPE also show good electrocatalytic activity toward the oxidation of carbohydrates (glucose, fructose and sorbitol). The Ni2+/ZnONPs-MWCNT-PMMA/CPE gives a good linear range with a detection limit of 8, 6, and 9 μM towards the determination of glucose, fructose and sorbitol, respectively by amperometry. Furthermore, the modified sensor was successfully applied to the sensitive determination of carbohydrates in real samples.

Electrochemical characterization of poly-beryllon II modified carbon paste electrode and its application to selective determination of pyrocatechol and hydroquinone

A poly-beryllon II film modified carbon paste electrode (PBL-II/CPE) has been constructed by electropolymerization method. Electrochemical characterization of the PBL-II/CPE was investigated by electrochemical impedance spectroscopy (EIS). The electrochemical behaviors of pyrocatechol (PC) and hydroquinone (HQ) were investigated by cyclic voltammetry (CV) and differential pulse voltammetry (DPV) at the PBL-II/CPE in pH 7.0 phosphate buffer solution (PBS). The anodic peak currents were dramatically enhanced about threefold for PC at PBL-II/CPE. In addition, the modified electrode exhibits good selectivity toward selective determination of PC and HQ. By using DPV method, low detection limits of 0.8μM for PC and 1.0μM for HQ were obtained, respectively. Many outstanding advantages, such as wide linear ranges, low detection limits, excellent sensitivity, selectivity and stability confirmed that the PBL-II/CPE has promising analytical performance. Meanwhile, the electrode was successfully used for the determination of PC and HQ in local tap water sample and the results are satisfactory.

Selective Detection of Dopamine in the Presence of Uric Acid Using Polymerized Phthalo Blue Film Modified Carbon Paste Electrode

A convenient and useful method for the voltammetric determination of dopamine (DA) and uric acid (UA) based on poly (Phthalo blue) modified carbon paste electrode (PTBMCPE) is reported in this paper. The PTBMCPE exhibits excellent electro-catalytic activities for the oxidationreduction of DA and UA, as well as eliminating the interference. Factors influencing the detection processes are optimized and the kinetic parameters are calculated. The effects of pH, scan rate and concentration of dopamine on the peak current were investigated, and the results indicated that the peak current of dopamine is the highest in 0.2 M pH 7.0 Phosphate buffer solution (PBS) and the electrode reaction corresponds to a rate-controlled process. The proposed method possesses the distinct advantages of simple, appropriate for operation, good reproducibility and highly selective and sensitive.

Electrodeposited antimony and antimony–gold nanocomposite modified carbon paste electrodes for the determination of heavy metal ions

Sb film modified carbon paste electrode (CPE) for the determination of Cd and Pb and Sb/Au composite material for the determination of Hg. Stripping plot of Cd and Pb using Sb film modified CPE and the stripping plot of Hg using Sb/Au composite modified CPE are shown along with the SEM image of the Sb/Au composite material.

Electrochemical detection of trace cadmium in soil using a Nafion/stannum film-modified molecular wire carbon paste electrodes

In this paper, a novel Nafion polymer-coated stannum film-modified carbon paste electrode was developed for the analysis of trace cadmium by square wave anodic stripping voltammetry. The electronic conductive material—molecular wire (diphenylacetylene)—was employed as the binder instead of traditional mineral oil for fabricating this electrode. It was found that the prepared electrode possessed excellent electrochemical performance and increased electron transfer rate due to the introduction of molecular wire as a binder, and exhibited a better sensitivity and stability as well as high resistance to surfactants due to the synergistic effect of Nafion and stannum film. Under the optimal conditions, the stripping peak currents showed a good linear relationship with the Cd(II) concentration in the range from 1.0 to 80.0 μg L−1 with a detection limit of 0.13 μg L−1 (S/N = 3). The developed electrode was further applied to the determination of Cd(II) in soil extracts with satisfactory results.

A simple and novel strategy for the simultaneous determination of dopamine, acetamidophenol and tryptophan based on poly(new coccine) film modified carbon paste electrode

A polymerized film of new coccine was deposited on a carbon paste electrode (CPE) by an electropolymerization technique. Electrochemical characterization of the modified electrode was investigated by electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The poly(new coccine) modified CPE exhibited excellent electrocatalytic activity towards the oxidation of dopamine (DA), acetaminophenol (AP) and tryptophan (Trp) simultaneously. Well defined and separated oxidation peaks were observed by CV. Linear calibration plots for the oxidation of DA, AP and Trp were obtained in the range of 0.7–200 μM for DA, 1.5–120 μM for AP, and 0.6–50 μM for Trp. Detection limits of DA, AP and Trp were found to be 0.2, 0.3 and 0.2 μM, respectively. With good selectivity and sensitivity, the present method has been successfully applied to the determination of DA, AP and Trp in pharmaceutical samples.

A novel hydrogen peroxide sensor based on immobilization of haemoglobin on nano-TiO2/DTAB composite film

The direct electron transfer of immobilized haemoglobin (Hb) on nano-TiO2 and dodecyltrimethylammonium bromide (DTAB) film modified carbon paste electrode (CPE) and its application as a hydrogen peroxide (H2O2) biosensor were investigated. On nano-TiO2/DTAB/Hb/CPE, Hb displayed a rapid electron transfer process with participation of one proton and with an electron transfer rate constant which estimated as 0.29 s− 1. Thus, the proposed biosensor exhibited a high sensitivity and excellent electrocatalytic activity for the reduction of H2O2. The catalytic reduction current of H2O2 was proportional to H2O2 concentration in the range of 0.2–4.0 mM with a detection limit of 0.07 mM. The apparent Michaelis–Menten constant (Kmapp) of the biosensor was calculated to be 0.127 mM, exhibiting a high enzymatic activity and affinity. This sensor for H2O2 can potentially be applied in determination of other reactive oxygen species as well.

Direct electrochemistry of adenine on multiwalled carbon nanotube–ionic liquid composite film modified carbon paste electrode and its determination in DNA

A novel, simple and reliable sensor based on multiwalled carbon nanotube–ionic liquid (1-ethyl-3-methylimidazolium hexafluorophosphate, EMIMPF6) composite film modified carbon paste electrode (MWCNT–IL/CPE) was proposed for direct electrooxidation behavior and determination of adenine. Compared with unmodified electrode, the modified electrode not only significantly enhanced the oxidation peak current but also lowered its oxidation peak potential. The electrochemical behavior of adenine on the modified electrode was carefully studied by cyclic voltammetry and the electrochemical parameters such as the electron transfer coefficient (α), the electrode reaction standard rate constant (ks), the area of the electrode (A), the electron transfer number (n) and the concentration of the electroactive adenine (ГT) were calculated with the results of 0.36, 3.65×10−6s−1, 1.4×10−3cm2, 2.04 and 7.43×10−9molcm−2 respectively. By using differential pulse voltammetry (DPV) as the detection method, a linear relationship was obtained between the oxidation peak current and the adenine concentration in the range from 5.0×10−7 to 7.5×10−5molL−1 with the detection limit of 1.089×10−9molL−1 (3σ) and the relative standard deviation (RSD) 6.5% (n=7) of 5×10−5molL−1 for adenine. The common coexisting substances showed no interferences to the adenine detection and the modified electrode showed good ability to distinguish the electrochemical response of adenine.

A novel hydrogen peroxide sensor based on hemoglobin immobilized PAn–SiO2/DTAB composite film

A novel hydrogen peroxide (H2O2) sensor based on hemoglobin (Hb) immobilized polyaniline–silica (PAn–SiO2) and dodecyltrimethylammonium bromide (DTAB) composite film modified carbon paste electrode (CPE) was fabricated and the direct electron transfer of immobilized Hb was investigated. On Hb/PAn–SiO2/DTAB/CPE, Hb displayed a fast electron transfer process accompanied with one proton participate in and its electron transfer rate constant which was estimated at 0.94s−1. Thus, the proposed biosensor exhibited a high sensitivity and excellent electrocatalytic activity to the reduction of H2O2. The catalytic reduction current of H2O2 was proportional to H2O2 concentration in the range of 0.09 to 2.8mM with the detection limit of 0.03mM. The apparent Michaelis–Menten constant (Kmapp) of the biosensor was calculated to be 0.275mM, exhibiting high enzymatic activity and affinity. With the characteristics above, the sensor in this paper can be potentially applied in other reactive oxygen species as well.

Selective determination of dopamine in presence of ascorbic acid and uric acid at hydroxy double salt/surfactant film modified carbon paste electrode

A sensitive and selective electrochemical method using a hydroxy double salt/surfactant film modified carbon paste electrode (HDS/SDS/CPE) was developed for the electrochemical determination of dopamine. The HDS/SDS/CPE shows an excellent electrocatalytic activity towards the oxidation of dopamine in 0.1M phosphate buffer solution (pH 7.4) and the detection limit of DA was 1×10−7M. The interference studies showed that the modified electrode exhibits an excellent selectivity towards dopamine (DA) in the presence of large excess of ascorbic acid (AA) and uric acid (UA). The separation of the oxidation peak potentials for DA–AA and DA–UA were about 187.8mV and 110.7mV respectively. The differences are large enough to determine AA, DA and UA individually and simultaneously. This work provides a simple and easy approach to selectively detect the dopamine in the presence of ascorbic acid and uric acid in physiological samples.

Electrocatalytic oxidation of tyrosine at poly(threonine)-film modified carbon paste electrode and its voltammetric determination in real samples

The electrochemical behavior of tyrosine on a poly(threonine)-film modified carbon paste electrode was explored in phosphate buffer solution (pH 7.0) using cyclic voltammetric technique. Tyrosine gave an oxidation peak at 687mV on bare CPE, whereas an oxidation peak at 671mV with enhanced peak current was obtained on the poly(threonine)-film modified electrode showing the electrocatalytic nature of the modified electrode. Cyclic voltammetric studies indicated that the oxidation of tyrosine at the electrode surface was irreversible, adsorption controlled and involves one electron. Linear calibration plot between the oxidation peak current and the tyrosine concentration was in the range of 5×10−7 to 1×10−5M and 1×10−5 to 2.0×10−4M with a correlation coefficient of 0.999 and 0.997, respectively. Detection limit of tyrosine was found to be 1×10−8M by differential pulse voltammetric technique. The effect of pH and scan rate of tyrosine was studied. The analytical performance of this sensor was evaluated for the detection of tyrosine in real samples.