Electroanalysis最新文献

Cover picture provided by Dr. Elena Benito-Peña and Dr. Susana Campuzano. Electroanalysis covers all branches of electroanalytical chemistry, including both fundamental and application papers as well as reviews dealing with analytical voltammetry, potentiometry, new electrochemical sensors and detection schemes, nanoscale electrochemistry, advanced electromaterials, nanobioelectronics, point-of-care diagnostics, wearable sensors, and practical applications.

The present study details a more environmentally friendly method for synthesizing iron oxide nanoparticles (Fe₃O₄-NPs) utilizing Hibiscus sabdariffa (H. sabdariffa) leaf extract. The produced H. sabdariffa/Fe₃O₄-NPs underwent characterization through VSM, XRD, FESEM-EDX, TEM and FTIR analyses. The FESEM and TEM images revealed that the H. sabdariffa/Fe₃O₄-NPs had a narrow distribution and an average particle size of 5±2 nm. Catalytic degradation studies of the synthesized Fe₃O₄-NPs exhibited efficient reduction of methyl orange (MO) dye. The degradation of MO catalysed by H. sabdariffa/Fe₃O₄-NPs follow the pseudo-first order kinetics, with a rate constant of 0.0328 s⁻¹ (R2=0.9866). Moreover, in electrochemical sensing studies, the anodic peak current of nitrite (NO₂⁻) for H. sabdariffa/Fe₃O₄-NPs/GCE showed a linear relationship with its concentration within the range of 0.5–7.5 mM, achieving a detection limit of 0.29 μM. These findings demonstrate that the modified electrode with Fe₃O₄-NPs synthesized using H. sabdariffa leaf extract serve as a novel electrochemical sensor for determining NO₂⁻ with high sensitivity and reproducibility.

A newly prepared solid contact ion selective electrode based on polyvinyl chloride membrane has been optimized and developed for determining nitrazepam in its pure form and synthetically prepared tablet dosage form. The proposed electrode was fabricated based on zeolite modified carbon paste electrode as a solid contact acting as a support for the membrane of PVC containing the ion complex of nitrazepam-tetraphenyl borate as an electroactive material, and the plasticizer dibutyl phthalate. By improving the composition, the potentiometric properties were further enhanced, and the sensor achieved a Nernstian slope of 60.89 mV dec⁻¹. The sensor was effective for detecting nitrazepam in the concentration range of 1.0×10⁻⁷ to 1.0×10⁻² M, with a detection limit of 4.7×10⁻⁸ M. The sensor demonstrated excellent reversibility and reproducibility with a fast response time and application over a wide pH range. The developed electrode showed no significant effect when tested with various interfering species. It is successfully applied for accurate determination of nitrazepam in pure form, synthetically prepared tablet and spiked human plasma. The developed technique was validated and demonstrated high accuracy and precision. When compared statistically with the official method, there were no significant differences observed.

The accumulation of harmful residuals can lead to voluminous environmental problems and then negatively affect human health. For this purpose, it is necessary to focus on the development of a rapid and sensitive strategy for its monitoring. In this work, a green, fairly fast, inexpensive and sensitive electrochemical sensor was developed to determine and monitor Cipro residues in various samples such as environmental resources, wastewater, urine, and drug formulations (Flonox 500 Aflox 500 and Cifloxine 250). It consists of a carbon paste electrode (CPE) modified with clay-supported reduced graphene oxide composite (GrGO/CL@CPE). The rGO was prepared using green and easily chemically converted GO (electrochemically prepared) to rGO nanosheets based on glucose (G) as a green reducing agent (GrGO). The proposed sensor demonstrates a high electro-oxidation signal compared with other based sensors, and the oxidation potential was found to be reduced by around 35 mV. The GrGO/CL@CPE was used for monitoring Cipro in the range of 0.05–10 μM in phosphate buffer at a biological pH of 7 (PB_7) and it offered a low detection limit (DL) (S/N=3) of 0.048 μM. Furthermore, it was found to be capable of detecting Cipro in pronounced samples with excellent results, offering promising prospects for actual clinical assays.