BiVO4–Bi2O3/ITO electrodes prepared by layer-by-layer: Application in the determination of atenolol in pharmaceutical formulations and urine

Electrochemical screening of selected β-blockers at a polarized liquid-liquid interface

This paper describes the electrochemical behavior of five β-blockers at the polarized liquid-liquid interface formed between aqueous solution (sodium chloride solution or Britton-Robinson buffers) and bis(triphenylphosphoranylidene)ammonium tetrakis(4-chlorophenyl)borate (BTPPATPBCl) dissolved in 1,2-dichloroethane (the organic phase). All measurements reported in this work were conducted using cyclic voltammetry (CV). The effects of the concentration of analytes, the pH of the aqueous phase, and applied electrochemical parameters on the analytical performance of the studied system are studied and discussed. The linear dynamic ranges (LDRs) of the studied β-blockers were in the range of 5-200 μmol L-1 and the lowest limit of detection (LOD) value was determined for pindolol (LOD = 1.96 μM μmol L-1). The highest LOD value was 4.96 μmol L-1 found for nebivolol. In addition, physicochemical parameters such as the formal Galvani potential difference (Δaqorgϕ), formal Gibbs free energies of the ion transfer reaction (ΔaqorgG') and partition coefficients (log P'aq/org) for all studied molecules were determined. The latter were compared and correlated with the available literature values of log Poctanol. Finally, a standard addition method was used to determine the concentration of nebivolol in pharmaceutical preparations using a platform based on the electrified liquid-liquid interface.

Gold nanoparticles coated with PVP as a novel colorimetric sensor for sensitive and selective determination of Atenolol

In this work, gold nanoparticles coated with polyvinylpyrrolidone (PVP-AuNPs) were used as a colorimetric probe for the sensitive, selective, simple, and rapid determination of atenolol (ATN). Indeed, atenolol triggered the aggregation of PVP-AuNPs via hydrogen bonding, electrostatic interactions, and dipole-dipole forces with PVP on the surface of AuNPs, causing the colloidal solution's color to shift from red to blue. SEM, TEM, FT-IR, UV-Vis, zeta potential, and other methods were used to characterise the PVP-AuNPs that were created as well as their aggregates. An excellent linear relationship between the absorption ratio (A690/A521) and the concentration of ATN in the range of 0.07-3.0 μM with a detection limit of 0.023 μM was discovered by optimising the experimental settings. The influence of potential interfering species on the measurement of ATN was investigated, and it was discovered that the developed colorimetric sensor had satisfactory selectivity. Finally, the presented method was used to measure ATN in tablet and blood plasma samples, and the obtained recovery values showed great promise for the use of the proposed sensor in clinical applications.

An ultra-sensitive laccase/polyaziridine-bismuth selenide nanoplates modified GCE for detection of atenolol in pharmaceuticals and urine samples

The analysis of β-blockers in pharmaceutical, biological and environmental samples has gained much interest due to their wide applications. The aim of this study was to develop an enzyme-based biosensor using hexagonal-shaped low-dimensional Bi₂Se₃ NPs decorated with laccase through polyaziridine (PAZ) modified glassy carbon electrode (Lac/PAZ-Bi₂Se₃ NPs/GCE). Surface properties were examined using SEM, TEM, EDX, XRD, XPS, FTIR, UV-Visible, and zeta potential. Electrochemical studies were performed with cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The enzymatic biosensor exhibited excellent catalytic activity towards the oxidation of ATN at +1.05 V (vs Ag/AgCl). Under the optimum experimental conditions, I_p (µA) was linearly related to the concentrations of ATN in the range of 3 to 130 µM (R² = 0.9972) with an LOD of 0.15 µM and 0.21 µM with and without Lac enzyme. Additionally, the validation of the biosensor was tested to determine ATN on within a day and between-day basis. The biosensor was applied successfully to detect ATN in real samples. The obtained recoveries range from 98.5 % to 99.2 % with an RSD (n = 5) of 0.95 (±0.02). The findings of this study have potential biomedical applications in drug detection employing a promising nano electrode sensor of Lac/PAZ-Bi₂Se₃ NPs/GCE.

Green synthesis and characterization of DyMnO3-ZnO ceramic nanocomposites for the electrochemical ultratrace detection of atenolol

The present study is a first report about magnetic, optical and electrical as well as drug sensing properties of DyMnO₃-ZnO green-nanocomposites that are synthesized by Pechini modified method. Three natural compounds containing Vitis vinifera, Hibiscus sabdariffa and rhus juices are used as green and eco-friendly reagents for synthesis of the nanostructures. The nanostructures are characterized by various techniques containing Fourier transform infrared spectra (FT-IR), X-ray diffraction (XRD), energy dispersive X-ray (EDX), field emission scanning electron microscopes (FESEM), high resolution transmission electron microscopy (HR-TEM), vibrating sample magnetometer (VSM) and diffuse reflectance spectroscopy (DRS). The calcination temperature, type of chelating agent and pH are optimized to achieve the best structural and smallest crystallite sizes of the systems via an eco-friendly approach. The studies show that the Vitis vinifera juice creates the best homogeneous sphere-like nanostructures. Therefore, the samples that are synthesized by Vitis vinifera juice are used for fabrication of a carbon paste electrode modified with DyMnO₃-ZnO nanocomposites (DMZN/CPE). The nanostructured modified electrode exhibits an excellent electrocatalytic effect for determination of atenolol (ATN) using voltammetry techniques. The results reveal that the DyMnO₃-ZnO green-nanocomposites have potential applications as a sensitive material in the drug analysis in biological samples.

Spectrofluorimetric determination of atenolol from human urine using high-affinity molecularly imprinted solid-phase extraction sorbent

This study presents a novel, sensitive and selective molecularly imprinted solid-phase extraction (MISPE)-spectrofluorimetric method for the removal and determination of atenolol from human urine. Molecularly imprinted and non-imprinted polymers were synthesized thermally using a radical chain polymerization technique and used as solid-phase extraction sorbents. Acrylic acid ethylene glycol dimethacrylate, dibenzoyl peroxide and dichloroethane were used as a functional monomer, cross-linker, initiator and porogen, respectively. The calibration curve was in the range of 0.10-2.0 μg/ml for the developed method. Limit of detection and limit of quantification values were 0.032 and 0.099 μg/ml, respectively. Owing to the selectivity of the MISPE technique and the sensitivity of spectrofluorimetry, trace levels of atenolol have been successfully determined from both organic and aqueous media. Relatively high imprinting factor (4.18) and recovery results (74.5-75.3%) were obtained. In addition, intra- and interday precision values were 0.38-1.03% and 0.47-2.05%, respectively, proving the precision of the proposed method. Thus, a selective, sensitive and simple MISPE-spectrofluorimetric method has been developed and applied to the direct determination of atenolol from human urine.