Fast microwave-assisted oxidation of 1,4-dihydropyridines with FeCl 3.SiO 2

Pyridine derivatives are easily obtained in high yields by microwave-promoted rapid oxidation of the corresponding 1,4-dihydropyridines with ferric chloride hexahydrate and silica gel under solvent-free conditions

Green Synthesis of Magnetic Nanocomposite with Iron Oxide Deposited on Cellulose Nanocrystals with Copper (Fe3O4@CNC/Cu): Investigation of Catalytic Activity for the Development of a Venlafaxine Electrochemical Sensor

A screen-printed electrochemical sensor based on Fe3O4@cellulose nanocrystals/Cu nanocomposite (Fe3O4@CNC/Cu) has been constructed for the sensitive detection of venlafaxine. The magnetic Fe3O4@cellulose nanocrystal/Cu nanocomposite was prepared by a green procedure using a plant extract (Petasites hybridus leaf) as a stabilizing and reducing agent for copper. The formation of Fe3O4@CNC/Cu was validated through X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy, field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, ultraviolet-visible spectral analysis, vibrating sample magnetometer, and thermal analysis. Fe3O4@CNC/Cu was next used for modifying a graphite screen-printed electrode, intended for the analysis of venlafaxine concentration. The electrochemical behavior of venlafaxine on the resulting electrode was evaluated through cyclic and differential pulse voltammetry and chronoamperometry. The tests indicated that the sensor has good performance for the electrochemical detection of venlafaxine. Under optimized conditions, the linear dynamic range for venlafaxine concentrations by the modified electrode was 0.05-600.0 μM, and the limit of detection was 0.01 μM. In addition, the developed technique was also demonstrated as a selective, easy, and precise sensor to identify venlafaxine in urine, water, and pharmaceutical formulation samples. © 2020 American Chemical Society

Naphthalene-fused (\u3b1-alkoxycarbonyl)methylene-\u3b3-butyrolactones: antiproliferative activity and binding to bovine serum albumin and DNA

A naphthalene-fused (\u3b1-alkoxycarbonyl)methylene-\u3b3-butyrolactone (methyl 2-[7-hydroxy-2-oxonaphtho[1,2-b]furan-3(2H)-yliden]acetate) has been prepared as a representative compound of a potential class of cytotoxic agents. In vitro cytotoxicity has been evaluated against HCT-15 colon and MCF-7 breast cancer cells and IC 50 was 64-66\u3bcM, causing morphological changes in cells, such as loss of adhesion, rounding, cell shrinkage, and detachment from the substratum. The binding constant K of the complex between the naphthyl lactone with bovine serum albumin (8 710 3 M -1) suggests a minor change in protein folding. The K of the binding with DNA (1.06 710 4 M -1) suggests nonspecific electrostatic interactions with DNA and this was confirmed by melting point data (Tm<0.6\ub0C). Therefore, naphthalene-fused (\u3b1-alkoxycarbonyl) methylene-\u3b3-butyrolactone should not be able to intercalate with DNA but its interaction should occur at the level of DNA surface

Recent Advances in Applications of Voltammetric Sensors Modified with Ferrocene and Its Derivatives

This study is on current developments concerning ferrocene (FC) and its derivatives on the basis of electrochemical biosensors and sensors. The distinct physiochemical characteristics of FC have enabled the development of new sensor devices, specifically electrochemical sensors. Several articles have focused on the implementation of FC as an electrode constituent while discussing its electrochemical behavior. Furthermore, typical FC-design-based biosensors and sensors are considered as well as practical examples. The favorable design of FC-based biosensors and general sensors needs adequate control of their chemical and physical characteristics in addition to their surface immobilization and functionalization. Copyright © 2020 American Chemical Society

Carbohydrate-based nanostructured catalysts: applications in organic transformations

The requirement of green and sustainable materials to prepare heterogeneous catalysts has intensified for practical reasons over the past few decades. Carbohydrates are possibly the most plentiful and renewable organic materials in nature with inimitable physiochemical properties, plausible low-cost and large-scale production, and sustainability features could be exploited in the generation of nanostructured heterogeneous catalysts. This review article outlines the organic transformations catalyzed by diverse carbohydrate-based nanostructured catalysts in greener and environmentally friendly processes. Selected examples are highlighted for a variety of organic reactions exploiting the proposed catalysts’ reactivity and reusability, and interactions with the intrinsic nature of the applied carbohydrate supports; advantages and speculated challenges of the introduced catalysts are deliberated as well. © 202

Recent developments in polymer nanocomposite-based electrochemical sensors for detecting environmental pollutants

The human population is generally subjected to diverse pollutants and contaminants in the environment like those in the air, soil, foodstuffs, and drinking water. Therefore, the development of novel purification techniques and efficient detection devices for pollutants is an important challenge. To date, experts in the field have designed distinctive analytical procedures for the detection of pollutants including gas chromatography/mass spectrometry and atomic absorption spectroscopy. While the mentioned procedures enjoy high sensitivity, they suffer from being laborious, expensive, require advanced skills for operation, and are inconvenient to deploy as a result of their massive size. Therefore, in response to the above-mentioned limitations, electrochemical sensors are being developed that enjoy robustness, selectivity, sensitivity, and real-time measurements. Considerable advancements in nanomaterials-based electrochemical sensor platforms have helped to generate new technologies to ensure environmental and human safety. Recently, investigators have expanded considerable effort to utilize polymer nanocomposites for building the electrochemical sensors in view of their promising features such as very good electrocatalytic activities, higher electrical conductivity, and effective surface area in comparison to the traditional polymers. Herein, the first section of this review briefly discusses the most important methods for polymer nanocomposites synthesis, such as in situ polymerization, direct mixing of polymer and nanofillers (melt-mixing and solution-mixing), sol-gel, and electrochemical methods. It then summarizes the current utilization of polymer nanocomposites for the preparation of electrochemical sensors as a novel approach for monitoring and detecting environmental pollutants which include heavy metal ions, pesticides, phenolic compounds, nitroaromatic compounds, nitrite, and hydrazine in different mediums. Finally, the current challenges and future directions for the polymer nanocomposites-based electrochemical sensing of environmental pollutants are outlined. © 2021 American Chemical Societ

Recent developments in conducting polymers: Applications for electrochemistry

Scientists have categorized conductive polymers as materials having strongly reversible redox behavior and uncommon combined features of plastics and metal. Because of their multifunctional characteristics, e.g., simplistic synthesis, acceptable environmental stability, beneficial optical, electronic, and mechanical features, researchers have largely considered them for diverse applications. Therefore, their capability of catalyzing several electrode reactions has been introduced as one of their significant features. A thin layer of the conducting polymer deposited on the substrate electrode surface can augment the electrode process kinetics of several solution species. Such electrocatalytic procedures with modified conducting polymer electrodes can create beneficial utilization in diverse fields of applied electrochemistry. This review article explores typical recent applications of conductive polymers (2016-2020) as active electrode materials for energy storage applications, electrochemical sensing, and conversion fields such as electrochemical supercapacitors, lithium-ion batteries, fuel cells, and solar cells. This journal is © The Royal Society of Chemistry

Iron molybdenum oxide-modified screen-printed electrode: Application for electrocatalytic oxidation of cabergoline

This research designed a simplified, sensitive electro-chemical procedure to detect cabergoline by a means of a screen-priented electrode (SPE) modified with Fe2MoO6 magnetic nanocomposite (Fe2MoO6/SPE). Fe2MoO6 magnetic nano-composite has been procured through a simplified procedure. According to the analyses, the final nanocomposite has been described by XRD, EDS, TEM, SEM and VSM analysis. The prepared modified electrode exhibited greater peak currents to oxidize cabergoline than that of the unmodified SPE. The analytical curve for the determination of cabergoline had very good linear response in the range between 0.08 and 300.0 µM for cabergoline. The detection limit for determining cabergoline was 0.02 µM. Finally, our technique has been substantially utilized for detecting cabergoline in the real samples. © 2020 Elsevier B.V

Fabrication of magnetic iron oxide-supported copper oxide nanoparticles (Fe3O4/CuO): Modified screen-printed electrode for electrochemical studies and detection of desipramine

The present investigation examines a sensitive electrochemical technique to detect desipramine through Fe3O4/CuO nanoparticles (NPs). Fe3O4/CuO NPs were synthesized via a coprecipitation procedure, and the products were characterized via energy disperse spectroscopy, X-ray diffraction, transmission electron microscopy, scanning electron microscopy, and vibrating sample magnetometer. The voltage-current curve and differential pulse voltammetry examinations of Fe3O4/CuO-modified screen-printed electrode (Fe3O4/CuO/SPE) were followed by the determination of electro-catalytic activities toward desipramine oxidation in a phosphate buffer solution (pH = 7.0). In addition, the value of diffusion coefficient (D = 3.0 � 10-6 cm2 s-1) for desipramine was calculated. Then, based on the optimum conditions, it was observed that the currents of the oxidation peak were linearly proportionate to the concentration of desipramine in the broad range between 0.08 and 400.0 μM and LOD of 0.03 μM (S/N = 3). Finally, our new sensor was successfully utilized to detect desipramine in the real samples, with reasonable recovery in the range of 97.2 to 102.7. This journal is © 2020 The Royal Society of Chemistry