Oxide Nanoparticles Modified Carbon Paste Research Articles

An ultrasensitive electrochemical platform based on copper oxide nanoparticles and poly (crystal violet) for the detection of brilliant blue FCF from soft drinks

In this study, a highly sensitive and quick electrochemical platform based on poly (crystal violet) film and copper oxide nanoparticles for the detection of brilliant blue FCF from various soft beverages was developed. The synthesized copper oxide nanoparticles were investigated with Fourier transform infrared spectroscopy, scanning electron microscopy, and energy-dispersive X-ray. Further, crystal violet was electropolymerized on the surface of the carbon paste electrode modified with copper oxide nanoparticles. The electrochemical properties of poly (crystal) violet/copper oxide nanoparticles modified carbon paste electrode were assessed through the utilization of cyclic voltammetry and electrochemical impedance spectroscopy. Furthermore, the signal towards the oxidation of brilliant blue was examined using the differential pulse voltammetry method. Under ideal experimental conditions, the peak current exhibited a linear relationship with the brilliant blue concentration within the range of 0.01–1.00 nmol/L, with a sensitivity of 294.55 µA nmol/L cm−2 and a significant detection limit of 3 pmol/L. In the presence of other dyes and other food additives, the developed platform showed greater selectivity in detecting brilliant blue. The reliability of the designed platform was demonstrated by the 99.19 – 100.67 recovery percentage for the identification of BB in various soft drink samples.

Sensitive determination of diuron on zinc oxide nanoparticles modified carbon paste electrode in soil and water samples

AbstractAn electrochemical sensor based on Zinc oxide nanoparticles (ZnONPs) modified carbon paste electrode was designed for the toxic diuron pesticide detection. The ZnONPs were synthesized through the hydrothermal route and their structural properties were investigated via scanning electron microscopy (SEM) and X‐ray diffraction powder (XRD). The designed ZnONPs‐modified carbon paste electrode (ZnONPs‐CPE) was characterized using cyclic voltammetry and electrochemical impedance spectroscopy. The sensor showed significantly enhanced sensitivity on the diuron oxidation peak current, compared to the bare carbon paste electrode. Qualitative and quantitative analysis were performed using cyclic voltammetry (CV) and square wave voltammetry (SWV). Experimental parameters such as pH, amount of ZnONPs and frequency were evaluated and the optimized conditions were obtained with 0.1 M phosphate buffer solution at pH=8, a frequency of 50 Hz and a quantity of 5 mg of ZnONPs. Under these conditions, linear responses ranging from 1.3 to 7.7 μM and 8.6 to 30 μM of diuron were obtained, with correlation coefficients of R2=0.994 and 0.996 respectively. Detection and quantification limits of 0.22 μM and 0.84 μM (S/N=3) were respectively achieved based on the 3σ method. The interference of some ions on the oxidation peak of diuron on ZnONPs‐CPE was also evaluated and no interference was observed, therefore demonstrating the selectivity of the sensor. The proposed sensor, designed with ecofriendly materials, is sensitive, selective and was effectively used for diuron determination in soils and water samples with recoveries ranging from 98 % to 101.5 %.

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.

Sensitive and selective determination of vitamin B2 in non-alcoholic beverage and milk samples at poly (glutamic acid)/zinc oxide nanoparticles modified carbon paste electrode

BackgroundThe deficiency of vitamin B2 can lead to many health problems. Therefore, it is necessary to develop a sensitive, selective and fast method for the determination of vitamin B2 in food samples. In this work, a sensitive, selective and low-cost electrochemical sensor was developed using poly (glutamic acid) and Zinc oxide nanoparticles (ZnO NPs) for vitamin B2 in non-alcoholic beverage and milk samples.MethodsThe modification of the electrode surface was carried out by electropolymerization of glutamic acid on ZnO NPs–carbon paste electrode (ZnO NPS–CPE). The prepared electrodes were characterized by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM) and X-Ray diffraction (XRD). CV and square wave voltammetry (SWV) were used to investigate the electrochemical behavior of vitamin B2 at the modified electrode. The effect of various parameters such as amount of ZnO NPs, polymerization cycle, concentration of the monomer, pH, scan rate and accumulation time were optimized to obtain maximum sensitivity at the modified electrode.ResultsThe developed sensor showed high electrocatalytic activity towards vitamin B2. Under the optimized conditions, the developed sensor showed a linear response in the range 0.005–10 µM with a low detection limit of (LOD) 0.0007 ± 0.00001 µM and high sensitivity of 21.53 µA/µM.ConclusionsA reproducible, repeatable, stable and selective sensor was successfully applied for the quantification of vitamin B2 in beverage and milk samples with acceptable recoveries in the range of 88–101%.

Highly Sensitive and Selective Chromium Oxide Nanoparticles Modified Carbon Paste Membrane Electrode to Determine Cr Concentration in Different Solutions

Highly Sensitive and Selective Chromium Oxide Nanoparticles Modified Carbon Paste Membrane Electrode to Determine Cr Concentration in Different Solutions

Zirconium Oxide Nanoparticles Modified Carbon Paste Electrode for Simultaneous Voltammetric Determination of Mebendazole and Levamisole Hydrochloride in Pharmaceutical Formulation and Human Plasma

AbstractA new, simple and highly sensitive electrochemical method based on zirconium oxide nanoparticles modified carbon paste electrode (2 % ZrO2/CPE) was used for simultaneous determination of anthelmintics drugs Mebendazole (MB) and Levamisole HCl (LV) in drug substance, dosage form and human plasma. Differential pulse (DPV) and square wave (SWV) voltammetric analysis were applied in Britton Robinson buffer (pH 6; 0.04 M) after optimization of different analytical parameters. The studied drugs were measured simultaneously at very low concentration of analytes resulting in two well‐separated peaks. The detection limits were found to be 0.01 and 0.62 μM for MB and LV, respectively, using DPV and 0.01 and 0.42 μM for MB and LV, respectively using SWV.

Electroanalytical determination of gallic acid in red and white wine samples using cobalt oxide nanoparticles-modified carbon-paste electrodes

Beverages like wines, have exhibited a high level of antioxidant capacity, specifically from compounds like Gallic acid (GA) and their derivatives. GA has shown great importance in the food industry and the pharmaceutical industry as a food additive, anti-tumour, anti-viral, and anti-mutagenic agent. Red and white wines from the USA and Australia were electrochemically analysed for GA, using Cobalt oxide nanoparticles modified carbon paste electrode (CoO-NPs-CPE). The electrochemical studies demonstrated an efficient GA (10 mmol L−1) oxidation, with enhanced peak currents from 302 µA to about 405 µA (25% increase). The limit of detection (LOD) of the modified electrode was 1.52 × 10−4 mmol L−1 within the concentration range of 1 × 10−4–1 × 10−3 mmol L−1. The CoO-NPs-CPE was successfully used, for the quantitative analysis of GA in red and white wine, showing average recoveries of 97% and 101% respectively. Hence our electrode can be applied for GA quantification in wine matrices.

Response Surface Modeling of Electrochemical Data for Sensitive Determination of Sudan III in Food Products at the Surface of a Nanocomposite Modified Electrode

In this work, application of a sensitive electrochemical technique assisted with multivariate optimization methods is presented for detection of Sudan III in food samples. At first, the synthesis and characterization of zinc oxide nanoparticles (ZnONPs) are described. The precipitation method is used for synthesis of ZnONPs with average particle sizes ranging from 20 to 30 nm. The structural analysis of the samples is performed using XRD. Also, the morphology and particle sizes of the ZnONPs are confirmed by SEM. Next, the nanoparticles are used for modification of a carbon paste electrode (CPE) surface. The modified electrode is used for investigation of electrochemical behavior of Sudan III. Electrochemical impedance spectroscopy (EIS) and differential pulse voltammetry (DPV) techniques are applied for characterization of the nanostructure modified electrode. For achieving the best response for Sudan III, effective experimental factors on the voltammetric determination of the analyte are optimized by rotatable central composite design (RCCD) and response surface methodology (RSM). The nanostructured modified electrode shows an excellent electrocatalytic property on the oxidation peak current of Sudan III. The electrochemical behavior of Sudan III at the surface of zinc oxide nanoparticles modified carbon paste electrode (ZnONPs/CPE) are investigated by differential pulse voltammetry (DPV), cyclic voltammetry (CV), and chronocoulometry. Analytical parameters such as linearity, selectivity, repeatability, and stability are also investigated. At the optimized conditions, the linear dynamic ranges for Sudan III are obtained 0.05–1.0 and 1.0–15.0 μM and the detection limit is achieved 2.56 nM. Also, the proposed sensor is successfully applied for detection of Sudan III in real complicated samples.

Fabrication of copper oxide nanoparticles modified carbon paste electrode and its application in simultaneous electroanalysis of guanine, adenine and thymine

Copper oxide nanoparticles (CuO NPs) were synthesized by the effortless co-precipitation method. The morphology, structure and optical characterization were investigated by scanning electron microscopy (SEM), X-ray diffraction, Fourier transform-infrared, (FTIR) and Ultra-Violet (UV) spectroscopy. The results specified that the resultant CuO NPs possess an average diameter of 12 nm and were effectively deposited on carbon paste electrode. The analytical performance of this novel CuO NPs modified carbon paste electrode (CuO NPsMCPE) was demonstrated the interference-free determination of guanine (G), adenine (A), and thymine (T) concurrently in a ternary mixture with phosphate buffer (PB) solution. The electrochemical investigation was carried out using cyclic voltammetry (CV), differential pulse voltammetry (DPV) and electrochemical impedance (EIS) spectroscopy demonstrated the potent and persistent electro-oxidation performance followed by well-separated oxidation peaks towards the detection of G, A and T. Besides this, the sensor manifested a wide linear range of 1–80 μM, 1–80 μM and 1–210 μM with the detection limit of 0.687, 0.472, and 0.111 μM for G, A and T correspondingly. The advantages of the deliberated sensor encompass good electrocatalytic activity, fast electron transfer rate, high accessible surface area and antifouling features towards the estimation and low investment of fabrication.

Electrochemical behavior of mefenamic acid at zinc oxide nanoparticles modified carbon paste electrode

Electrochemical oxidation of mefenamic acid at zinc oxide nanoparticles modified electrode was performed. Comparison of bare carbon paste electrode and zinc oxide nanoparticles modified carbon paste electrode, it was observed that the modified electrode has advantage of high sensitivity and selectivity with low detection limit. Effect of supporting electrolyte (phosphate buffer, I = 0.2 M) solution in the range, 3.0 – 11.2 pH was investigated and found that pH 5 is suitable for the investigations. In addition, effect of scan rate variations was studied to calculate some of the physiochemical properties. A differential pulse voltammetric method was developed for the analytical application. Low detection limit and quantification of 5.13 x 10 –10 and 1.17 x 10 –9 M respectively in the linearity range 1.0 x 10 –6 to 2.0 x 10 –8 shows that the developed method has a wide advantage over early reported methods. Further, the applicability of the method was investigated for pharmaceutical dose form and human urine samples

Green synthesis and characterization of cobalt oxide nanoparticles and its electrocatalytic behavior

Green synthesis of pure cobalt oxide nanoparticles (CoO-NPs) in aqueous medium has been carried out using gelatin. The main advantage of using gelatin as a stabilizing agent is that it provides long-term stability for nanoparticles by preventing particles agglomeration. The particles have been characterized using X-ray diffraction (XRD), transmission electron microscope (TEM), scanning electron microscopy (SEM), energy dispersive X-ray (EADX), and thermogravimetric analysis (TGA). TEM image shows the formation of CoO-NPs with average particle size of 28 nm which agrees well with the XRD data. Cobalt oxide nanoparticles modified carbon paste electrode (CoO-NPs/CPE) displayed excellent electrochemical catalytic activities towards the oxidation of glucose. The electrocatalytic response showed a wide linear range of 7–1000 µM, as well as its experimental limit of detection can be achieved 5.3 µM. The modified electrode for glucose determination is of the property of simple preparation, good stability and high sensitivity.

CuO-nanoparticles modified carbon paste electrode for square wave voltammetric determination of lidocaine: Comparing classical and Box–Behnken optimization methodologies

In this research, copper oxide nanoparticles modified carbon paste electrode was developed for the voltammetric determination of lidocaine. The square wave voltammogram of lidocaine solution showed a well-defined peak between +0.5 and +1.5 V. Instrumental and chemical parameters influencing voltammetric response were optimized by both one at a time and Box–Behnken model of response surface methodology. The results revealed that there was no significant difference between two methods of optimization. The linear range was 1–2500 μmol L−1 (Ip = 0.11CLH + 17.38, R2 = 0.999). The LOD and LOQ based on three and ten times of the signal to noise (S/N) were 0.39 and 1.3 μmol L−1 (n = 10), respectively. The precision of the method was assessed for 10 replicate square wave voltammetry (SWV) determinations each of 0.05, 0.5 and 1 mmol L−1 of lidocaine showing relative standard deviations 4.1%, 3.7% and 2.1%, respectively. The reliability of the proposed method was established by application of the method for the determination of lidocaine in two pharmaceutical preparations, namely injection and gel.

Ethanol electrooxidation at carbon paste electrode modified with Pd–ZnO nanoparticles

The electrocatalytic and analytical performance of palladium–zinc oxide nanoparticles modified carbon paste electrode (Pd–ZnO/CPE) for determination and oxidation of ethanol were studied in alkaline media. X-ray diffraction (XRD) and transmission electron microscopy (TEM) was used to characterize Pd–ZnO nanoparticles. The electrochemical characterizations were performed using cyclic voltammetry (CV) and chronoamperometry techniques. The results show that the electrode reveals excellent electrocatalytic characteristics for ethanol oxidation such as high catalytic activity, stability and tolerance toward poisoning effects. Also, the excellent analytical performance for ethanol determination confirms the applicability of this electrode as a nonenzymatic amperometric ethanol sensor. This sensor has the advantages of low detection limit (20.3μM), two wide linear range (1.99–490.90mM and 0.491–3.355M), and good long-term stability (more than 120 days) for ethanol determination. All results showed that palladium–zinc oxide nanoparticle is a good candidate for application in ethanol sensor and ethanol fuel cells.

Electroanalytical Characterization of Montelukast Sodium and Its Voltammetric Determination in Pharmaceutical Dosage Form and Biological Fluids

The electrochemical properties of montelukast sodium (MKST) at zinc oxide nanoparticles modified carbon paste electrode were investigated by cyclic voltammetry and square wave voltammetry. All studies were based on the irreversible and adsorption-controlled electrochemical reduction signal of montelukast sodium at about -0.7 vs. Ag/AgCl at pH 2.3 in methanol-Britton-Robinson buffer mixture. This adsorptive character of the molecule was used to develop a novel, validated, rapid, selective and simple square wave cathodic adsorptive stripping voltammeric method for the direct determination of montelukast sodium in pharmaceutical and biological fluids without time-consuming steps prior to drug assay. Peak current of electrochemical reduction of montelukast sodium was found to vary linearly with the concentration in the range from 1.0 × 10-8 to 1.28 × 10-6 mol L-1. In this method, limit of detection was found to be 7.7 × 10-9 mol L-1. The method was applied to determine the content of MKST tablet and spiked human serum.

Indium oxide nanoparticles modified carbon paste electrode for sensitive voltammetric determination of aromatase inhibitor formestane

This paper reports a novel, simple and sensitive electrochemical method for the determination of formestane (FMT) in aqueous media (BR buffer solution, pH 5.2) on indium oxide nanoparticles modified carbon paste electrode (In2O3 NPs/CPE). The prepared In2O3 nanoparticles were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The fabricated In2O3 NPs/CPE displayed high effective surface area, more reactive sites and excellent electrochemical catalytic activity toward the oxidation of FMT. The voltammetric oxidation of FMT was studied at a carbon paste and indium oxide nanoparticles modified carbon paste electrodes by cyclic voltammetry and its determination was carried out by square wave anodic adsorptive stripping voltammetry (SWAASV). The electrochemical parameters such as surface concentration (Г), electron transfer coefficient (α), and the electron transfer rate constant (ks) of FMT at the modified electrode were calculated. Under the optimal conditions at In2O3 NPs/CPE, a linear relationship was realized between the anodic peak currents and FMT concentrations in the range of 0.19–2.91μM, with the detection limit of 6.2×10−8M. This modified electrode was used as a sensor for determination of FMT in blood serum and urine samples with satisfactory results.

Determination of trace heavy metals in milk using an ionic liquid and bismuth oxide nanoparticles modified carbon paste electrode

A novel carbon composite electrode modified with bismuth oxide nanoparticles and the ionic liquid n-octylpyridinium hexafluorophosphate was fabricated and used to simultaneously determine cadmium and lead levels using square wave anodic stripping voltammetry. This electrode combines the unique advantages of nanomaterials and ionic liquid with the low cost and easy fabrication of the carbon composite electrode. Compared with the traditional binder based composite electrode, our electrode exhibited well-defined and separate stripping voltammetric peaks for cadmium and lead. Furthermore, the antifouling capacity of the bismuth film electrode was significantly improved by the ionic liquid. Under optimized conditions, the linear range of the composite electrode was from 3.0 to 30.0 μg L−1 for both metal ions with a detection limit of 0.15 μg L−1 for cadmium and 0.21 μg L−1 for lead. Trial milk sample analyses showed that the modified electrode was sensitive, reliable and effective for the determination of trace heavy metals, holding great promise for routine analysis applications.

Voltammetric behavior of multi-walled carbon nanotubes modified electrode-hexacyanoferrate(II) electrocatalyst system as a sensor for determination of captopril

Abstract The study of electrochemical behavior and determination of captopril, as an angiontensin-converting enzyme inhibitor, is reported on multi-walled carbon nanotube (MCNT) modified glassy carbon electrode (GCE) and hexacyanoferrate(II) (HCF) electrocatalyst. The cyclic voltammetric results indicate that MCNTs and HCF system can remarkably enhance electrocatalytic activity toward the oxidation of captopril in acidic solutions. It is leading to a considerable improvement of the anodic peak current for captopril, and allows the development of a highly sensitive voltammetric sensor for detection of captopril in pharmaceutical and clinical samples. The investigation of captopril oxidation on the iron oxide nanoparticles modified carbon paste electrode does not show any electrocatalytic effect on the oxidation of captopril, suggesting that iron oxide impurities in the MCNTs are not the active sites in captopril sensing. Under optimized conditions on MCNTs-HCF system, the proposed method with respect to other reported electrochemical methods shows wider dynamic range (0.5–600 μM) with suitable selectivity, practical detection limit of 0.2 μM and good precision (R.S.D.