Analytical & Bioanalytical Electrochemistry
Volume:14 Issue: 10, Oct 2022

Computational chemistry induced several fast, cost-effective revolutionary solutions for chemistry laboratories. The reliability of such solutions has been questioned in several studies. The current work introduces an experimental validation for the computational selection of an ionophore during potentiometric sensor optimization. We studied the correlation of the experimental sensor performance parameters to the computational binding scores of the embedded ionophores and the drug (loperamide hydrochloride). The study included eight sensors of different PVC-membrane compositions. The PVC-membrane containing phosphotungstic acid, dioctyl phthalate, and carboxymethyl-β-cyclodextrin developed a Nernstian slope of 59.69 mV/decade and a detection limit of 2.95×10-7 mol L-1. The sensor demonstrated a fast and stable response within a linear range of 2.99×10-6-9.09×10-3 mol L-1. We examined the drug-ionophore binding using molecular modeling and docking. The docking scores (binding energy) of the cyclodextrin derivatives strongly correlate to the studied sensors' experimental performance parameters (Nernstian slope). Performance and validation parameters were computed, and the results were statistically comparable to those of the reported method. Practically, the absence of sample preparation, chromatographic separation, high-purity solvents, and costly instrumentation are incomparable advantages of the developed method relative to the reported ones.

The precipitation method was utilized to prepare MgO nanoparticle (MgO/NPs) without using surfactant in this study, the MgO/NPs was examined by XRD, SEM, and EDS analysis. The MgO/MCPE was developed and used for the oxidation of paracetamol (PA) in presence of ascorbic acid (AA) study by using cyclic voltammetric (CV) and differential pulse voltammetric (DPV) techniques. Finally, the developed sensor shows good electrocatalytic performance in pH and scan rate studies. From the concentration study for the voltammetric determination of PA, the limit of detection was found to be 4.33 µM for PA at MgO/MCPE, the practical purpose of the MgO/MCPE was utilized to evaluate PA in real sample analysis.

This study depicts the plan, optimization, validation, and utilization of a novel polyvinylchloride (PVC) lattice-assisted membrane sensor to quantify fexofenadine hydrochloride (FFH) by utilizing Alizarin Red S (ARS), β-cyclodextrin (β-CD) and nitrophenyl octyl ether (NPOE) as an ion-exchanger, ionophore, and plasticizer respectively. The PVC network-assisted FFH-ARS sensor answers in <15s with super Nernstian conduct for FFH over 2.5×10-6-1.25×10-3 mol L-1 in the pH of 2.0 to 5.5 range. The regression coefficient acquired for the alignment plot is 0.9921. The determined Nernstian slope of the line is 56.18±1.25 mV/decade. The detection limit (LOD) is viewed as 3.5×10-7 mol L-1. Validation results clarified its appropriateness to assay FFH precisely and definitively. The sensor is a decent one for robust and rugged capability with a mean RSD of 4.39%. The outcomes of the interference study confirmed the non-interference of foreign ions while measuring the potentials. Statistical comparison of the outcomes confirms the good agreement of results of the proposed analytical procedure with the reference one. The percentage of mean recovery of FFH utilizing the proposed FFH-ARS sensor was 98.56 and 95.61% for the tablets and spiked human urine respectively, and this affirmed the selectivity of the solid-state electrode for FFH.

The present paper describes the fabrication of a new potentiometric sensor to determine Cerium(III) ion based on a carbon paste electrode (CPE) as an indicator electrode. Four components, including N,N-bis(salicylidene)-1,3-propanediamine as the ionophore, graphite powder, ionic liquid ([HMIM][PF6]) as the binder, and carboxyl functionalized MWCNTs as the modifier, was used to fabricate the CPE. The percentage of each CPE component was optimized using a simplex lattice mixture design, including 20 experimental runs. The optimum amount of ionophore, graphite powder, ionic liquid, and carboxyl functionalized MWCNTs was 0.1409, 0.5405, 0.2000, and 0.1186, respectively. The fabricated CPE with an optimum composite showed the Nernstian response in terms of 19.77 slope (mV/decade) and response time (<8 s) for the Ce(III) ion determination in the concentration range of 1.0×10-8-1.0×10-3 M with a proper detection limit (5.17×10-9 M). Besides, the potentiometric response of the sensor was constant in the pH range of 4-9. The sensor was successfully utilized to determine the endpoint of the Ce(III) ion titration with a standard solution of EDTA as a titrant. Also, the sensor was applied to analyze soil and real water samples with recoveries between 90.7-104.2% and RSDs lower than 3.94%. The advantages of the sensor include simple fabrication, low cost, easy operation, wide linear range, short response time, high lifetime, and suitable selectivity.

In this present work, NiMn2O4 nanostructures were prepared by using KOH/NaOH double hydroxide solution by hydrothermal method. The structure and chemical composition of the prepared material was confirmed by XRD and FT-IR, respectively. HR-TEM revealed the surface morphology of the NiMn2O4. The enhanced electrochemical properties of the NiMn2O4 material were examined by the CV, CP, and EIS analyses. The supercapacitor based on the nanostructured NiMn2O4 revealed the higher specific capacitance (854.7 F/g at 5mV/s in 2 M aqueous KOH electrolyte), better performance and cyclic stability (94.6% capacitive retention after 1000 cycles at 4 A/g). The hexagonal morphology plays an important role in enhancing the specific capacitance of the electrode. The electrochemical behaviors infer that the hexagonal-like NiMn2O4 nanostructured electrode can be potentially used in supercapacitors.

Severe Acute Respiratory Syndrome Coronavirus-2 (SARS CoV-2) caused the burden of coronavirus infectious disease 2019 (COVID-19) and spread all of the world. Evaluation of antibodies is the most typical diagnostic method is utilized to detect SARS-COV-2. Quick and high-specific diagnosis of specific antibodies can be the best way to evaluate the vaccine efficiency and decrease the number of the disease. In this study, before discussing the types of biosensors designed for the specific detection of SARS CoV-2 virus in these few years, we have summarized the serological methods in antibody detection and pointed out some of its advantages and disadvantages. In recent decade, biosensors have appeared to complement ELISA and PCR for pathogen detection. In two years ago, Electrochemical, colorimetric and fluorescence biosensors based on various nanomaterials are developed for SARS-COV-2 specific Abs detection with high specificity and sensitivity. This article specifically deals with the detection of specific antibodies of Covid-19 by biosensor methods and it is an update of similar articles. Considering that one of our goals was to investigate new biosensor methods for diagnosis, we tried to select studies related to Covid-19 specific Abs mostly between 2019 and 2021.