Cobalt oxide nanoparticles electrodeposited on glassy carbon electrode for metronidazole determination

Herein, we introduced a sensing platform for the electrochemical determination of metronidazole (MTZ) via a modified glassy carbon electrode (GCE) by cobalt oxide nanoparticles (CoOX NPs). Co NPs were deposited onto GCE in a solution containing CoSO4 and Na2SO4 by repetitive potential cycling. In the next step, the modified electrode was positioned in a hydroxide solution and scanned repetitively to stabilize and activate the Co NPs. The surface morphology of the CoOX NPs onto the GCE was characterized by energy dispersive X-ray (EDX) spectroscopy and scanning electron microscopy (SEM). The electrochemical activity of the modified electrode towards the reduction of MTZ was studied by differential pulse voltammetry (DPV) and cyclic voltammetry (CV). The peak current showed a linear response to MTZ concentration from 6.95 to 982.98 µM, with a limit of detection of 3.12 µM (S/N = 3), using differential pulse voltammetry. The proposed assay was applied for the analysis of MTZ in medicinal samples

Electrocatalytic Determination of Isoniazid by a Glassy Carbon Electrode Modified with Poly (Eriochrome Black T)

In this work poly eriochrome black T (EBT) was electrochemically synthesized on the glassy carbon electrode as electrode modifier. On the modified electrode, voltammetric behavior of isoniazid (INH) was investigated. The poly (EBT)-modified glassy carbon electrode has excellent electrocatalytic ability for the electrooxidation of isoniazid. This fact was appeared as a reduced overpotential of INH oxidation in a wide operational pH range from 2 to 13. It has been found that the catalytic peak current depends on the concentration of INH and solution pH. The number of electrons involved in the rate determining step was found 1. The diffusion coefficient of isoniazid was also estimated using chronoamperometry technique. The experimental results showed that the mediated oxidation peak current of isoniazid is linearly dependent on the concentration of isoniazid in the ranges of 8.0 × 10-6 – 1.18 × 10-3 M and 2.90 × 10-5 M – 1.67× 10-3 M with differential pulse voltammetry (DPV) and amperometry methods, respectively. The detection limits (S/N = 3) were found to be 6.0 μM and 16.4 μM by DPV and amperometry methods, respectively. This developed method was applied to the determination of isoniazid in tablet samples with satisfactory results

Enhanced electrocatalytic activity of fluorine doped tin oxide (FTO) by trimetallic spinel ZnMnFeO4/CoMnFeO4 nanoparticles as a hydrazine electrochemical sensor

Abstract In the present study, ZnMnFeO4 and CoMnFeO4 tri-metallic spinel oxide nanoparticles (NPs) were provided using hydrothermal methods. The nanoparticles have been characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), Fourier transform infrared spectroscopy (FTIR), energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), and electrochemical techniques. A reliable and reproducible electrochemical sensor based on ZnMnFeO4/CoMnFeO4/FTO was fabricated for rapid detection and highly sensitive determination of hydrazine by the DPV technique. It is observed that the modified electrode causes a sharp growth in the oxidation peak current and a decrease in the potential for oxidation, contrary to the bare electrode. The cyclic voltammetry technique showed that there is high electrocatalytic activity and excellent sensitivity in the suggested sensor for hydrazine oxidation. Under optimal experimental conditions, the DPV method was used for constructing the calibration curve, and a linear range of 1.23 × 10−6 M to 1.8 × 10−4 M with a limit of detection of 0.82 ± 0.09 μM was obtained. The obtained results indicate that ZnMnFeO4/CoMnFeO4/FTO nano sensors exhibit pleasant stability, reproducibility, and repeatability in hydrazine measurements. In addition, the suggested sensor was efficiently employed to ascertain the hydrazine in diverse samples of cigarette tobacco

Net analyte signal standard addition method for the simultaneous determination of cadmium and nickel

A novel net analyte signal standard addition method (NASSAM) is presented for the simultaneous determination of Cd2+ and Ni2+ in their mixture by differential pulse polarography. The method combines the advantages of the standard addition method with the net analyte signal concept, which enables the extraction of information concerning a certain analyte from voltammograms of multi-component mixtures. This method has some advantages, such as: the use of a full voltammogram, realization in a single step, therefore it does not require calibration and prediction steps and only a few measurements are required for the determination. The simultaneous determination of Cd2+ and Ni2+ was performed in Britton–Robinson buffer (pH 2.87) and 0.40 M potassium thiocyanate solution.saturated with water were determined

JSCS–3877 Original scientific paper

Net analyte signal standard addition method for the simultaneous determination of cadmium and nicke

Application of Multivariate Calibration Methods, in Dissolution Testing and Simultaneous Determination of Atorvastatin and Ezetimibe in Their Combined Solid Dosage Form

Background: Two simple, precise and accurate multivariate calibration methods, partial least square (PLS) and principal component regression (PCR) have been applied for the simultaneous determination and dissolution profile evaluation of atorvastatin (ATV) and ezetimibe (EZT) in their binary mixtures and commercial tablets. Due to the closely overlapping spectral bands of the mentioned drugs, simultaneous determination without previous separation is not possible by conventional spectrophotometric methods. In the proposed methods (PLS and PCR) determination of chemicals was performed by the use of a full-spectrum multivariate calibration method. Methods: The experimental calibration matrix was designed orthogonally with 16 samples composed of different mixtures of both compounds in related mediums. The simultaneous determination of ATV and EZT was accomplished in mixtures through recording the absorption spectra within a range of 210 to 300 nm. Results: The concentration of ATV and EZT were considered in the linear range, between 8 to 14 µg.ml-1. The specificity of the methods was evaluated by analyzing laboratory prepared mixtures of the mentioned drugs in specific proportions. Conclusion: The applied methods were successfully employed in simultaneous spectrophotometric determination and dissolution profile evaluation of ATV and EZT in their prepared mixtures and pharmaceutical formulation

An ultrasensitive and preprocessing-free electrochemical platform for the detection of doxorubicin based on tryptophan/polyethylene glycol-cobalt ferrite nanoparticles modified electrodes

© 2022 Elsevier B.V.Doxorubicin (DOX) is an anticancer drug which can effectively inhibit the growth of cancer cells and aids the immune-mediated elimination of tumoral cells. Developing a new technique for analysis of DOX in clinical fluids is highly required. Here, a novel electrochemical sensor was designed using tryptophan (Trp)/(polyethylene glycol)PEGylated-CoFe2O4 nanoparticles to modify glassy carbon electrodes’ surface and was utilized to determine DOX in unprocessed human plasma samples. PEGylated-CoFe2O4 nanoparticles were coated on the surface of the glassy carbon electrode to provide the PEGylated-CoFe2O4/GCE probe. Under optimized conditions, the low limit of quantification (LLOQ) of the proposed sensor was 30 ng/mL and the linear ranges for the determination of DOX were 30 ng/mL to 1.0 μg/mL and 1.0 μg/mL to 5.0 μg/mL, respectively. PEG molecules provided an antifouling effect to prevent precipitation of the macromolecules on the surface of the fabricated electrode. Obtained results indicated that the suggested electrochemical sensor can be utilized for specific and sensitive determination of DOX in plasma samples