Lanthanum vanadate-based carbon nanocomposite as an electrochemical probe for amperometric detection of theophylline in real food samples.

Theophylline (THP) is an emerging drug for chronic obstructive pulmonary disease whose side effects can be greatly affected by caffeine-containing real foods. Because an overdose of this substance can cause respiratory and neurological damage, producing a fast and accurate analytical procedure is critical. Based on a cutting-edge hybrid nanocomposite, this study was used to construct an electrochemical sensor for the accurate detection of THP. Spectroscopy and morphological investigation supported the easy synthesis of tetragonal-LaVO4 (t-LV) nanopellets and LV@CNF hybrid nanocomposite. To detect THP, a highly dispersed LV@CNF nanocomposite was modified on a glassy carbon electrode as a sensing substrate. By amperometric technique, the sensor shows a wide linear range of 0.01-1070 µM, low limit of detection (2.63 nM), and sensitivity (0.228 µA µM-1 cm-2). Finally, the current technique was successfully used to identify THP in real food samples (chocolate, coffee and black tea).

Cold Sintering Process for a BaTiO3/Poly(vinylidene difluoride) Ceramic-Polymer Composite: Evaluation of the Structural and Microwave Dielectric Properties.

The sintering process is essential to transforming particular material into dense ceramics. Although several sintering techniques have emerged over the past few years, the process is still performed at high temperatures. The alternative cold sintering process (CSP) is a potential strategy for producing an advance high dielectric permittivity and enables densification at low temperature. In this process, the CSP technique has been applied to successfully prepare the BaTiO3/poly(vinylidene difluoride) (PVDF) nanocomposite. The inorganic material of the BaTiO3/PVDF nanocomposite was confirmed by various physical characterizations, and the densification studies were performed using a semiautomated press, indicating a dissolution-precipitation mechanism. When a uniaxial pressure of 350 MPa was applied, with transient liquid could be sintered at 190 °C, and a relative density of 94.8%. The nanocomposite exhibits an excellent dielectric properties like εr = 71.1 and tan δ = 0.04 with frequency range at 1 GHz for various dwelling times and maximize the electrical resistivity. The BaTiO3/PVDF composite indicating a breakthrough opportunity toward an increase of the high dielectric constant will be significantly impacted by cold sintering. It enables innovative materials design and integrated devices to advance modern electronic industry applications.

Construction of functionalized carbon nanotube@metal oxide nanocomposite for high-performance electrochemical measurement of antipyretic drug in water samples.

Acetaminophen (AP) acts as supportive clinical therapy for fever and dysmenorrhea. An overdose of AP may result in severe adverse diseases, such as liver dysfunction. In addition, AP is a key-listed environmental pollutant, which is difficult to degrade in the environment and has serious effects on living bodies. Therefore, the simple and quantitative determination of AP is highly relevant today. In this work, tin dioxide (SnO2) nanoparticles with functionalized multi-walled carbon nanotube (f-MWCNT) as a hybrid composite were prepared by hydrothermal-assisted synthesis. The composite material was characterized by various spectral, morphological, and electrochemical tests. Electrochemical investigations were conducted using a SnO2@f-MWCNT-reinforced electrode for the detection of AP. The composite electrode exhibited better functional properties, which facilitated electron transfer and enhanced electrical conductivity. The calculated low detection limit (LOD) of 0.36 nM is with a wide linear range of concentration from 0.001 to 673 µM. Additionally, the SnO2@f-MWCNT-modified electrode exhibited good anti-interference capability, repeatability, reproducibility, storage, and operational stability. The developed SnO2@f-MWCNT-modified electrode was applied to practical analysis in diverse water matrices (river, drinking, and pond) with acceptable recovery percentages. A synthesized nanoscale metal oxide electrocatalyst is of great interest and an active research area that serves as a foundation for the development of new, cost-effective electrochemical antibiotic drug sensors.

Modification of glassy carbon electrode with manganese cobalt oxide-cubic like structures incorporated graphitic carbon nitride sheets for the voltammetric determination of 2,4,6 -trichlorophenol.

Novel cube-like transition metal oxide embedded on graphitic carbon nitride (MCO@GCN) formed a hybrid composite via hydrothermal assisted sonochemical synthesis. The synthesized composite was examined with various physical characterizations such as morphological SEM, EDX, XRD, and FT-IR spectroscopy. The electrocatalytic activity of MCO@GCN composite was further investigated when used  to modify a glassy carbon electrode (GCE). The electrochemical sensor was investigated using modified MCO@GCN/GCE towards environmental pollutant 2,4,6-trichlorophenol (2,4,6-TCP) detection with at a potential of (+ 0.654 V vs Ag/AgCl) in pH-7. The structural features have favored a high charge transfer ratio with excellent conductivity which showed a low detection limit (LOD) of 0.0068 µM and sensitivity of 23.57 µA·µM-1·cm-2 comprising a wide linear working range of 0.01-1720 µM by using differential pulse voltammetry. Besides, the MCO@GCN/GCE displayed excellent selectivity , repeatability, reproducibility, storage, and operational stability. Notably, the proposed MCO@GCN/GCE was validated with different environmental samples (tap, river, and industrial water) with RSD 0.62-2.86% and 96.51-99.66% (n = 3) recovery.

Solvothermal synthesis of silver tungstate integrated with carbon nitrides matrix composites for highly sensitive electrochemical nitrofuran derivative sensing in biological samples.

In the present research, we aimed to develop a novel electrochemical method based on transition metal tungstate nanorods incorporated sulfur doped carbon nitrides matrix (Ag2WO4@SGCN) for determination of antibiotic drug. The morphological and structural analysis of the prepared Ag2WO4@SGCN were performed by various techniques including SEM, EDS, XRD, and EIS. Under the optimal conditions of the sensor, the Ag2WO4@SGCN modified electrode showed outstanding electrocatalytic performance toward the electro-reduction of nitrofurantoin (NFT) with a significant increase in cathodic peak currents in comparison with the bare electrode. By differential pulse voltammetric (DPV) method the fabricated nitrofurantoin sensor gave linear response in the concentration range from 0.005 to 935 µM with detection limit (3Sb/m) of 0.0013 µM. Importantly, the practically of the proposed Ag2WO4@SGCN modified electrode was demonstrated in different biological samples. In addition, Ag2WO4@SGCN electrode displayed excellent anti-interfering ability and repeatability, reproducibility, storage and operational stability has been successfully demonstrated for detection of NFT.

Hydrothermally synthesized cubical zinc manganite nanostructure for electrocatalytic detection of sulfadiazine.

An electrocatalyst modified electrode has been investigated to develop the rapid detection of antibiotics. The modified electrocatalyst was intended for the determination of sulfadiazine (SFZ) in biological fluids by electrochemical methods. Nanocube of zinc manganite (ZnMn2O4-NC) is prepared by hydrothermal method and a glassy carbon electrode (GCE) has been modified with the zinc manganite. The ZnMn2O4/GCE exhibit enhanced detection performances towards SFZ drug owing to their selective adsorption ability and the combination of electrostatic attraction of nanocube with SFZ. The modified electrocatalyst shows excellent electrocatalytic interactions with antibiotic drug. Besides, the modified sensors exhibit nanomolar detection limit (0.0021 µM) in 0.05 M phosphate buffer (pH = 7.0) using differential pulse voltammetric method. The working range of the modified electrode is 0.008-1264 µM, and the sensitivity of the SFZ sensor is 11.44 µA µM-1 cm-2. The modified sensor stability and reproducibility performances have been examined by electrochemical method. In addition, the obtained results of real sample analysis with different concentrations of SFZ in biological fluids are satisfactory with good recovery.

Layered nanocomposite of zinc sulfide covered reduced graphene oxide and their implications for electrocatalytic applications.

Herein, we have synthesized zinc sulfide nanospheres (ZnS NPs) encapsulated on reduced graphene oxide (RGO) hybrid by an ultrasonic bath (50 kHz/60 W). The physical and structural properties of ZnS NPs@RGO hybrid were analyzed by TEM, XRD, EIS and EDS. As-prepared ZnS NPs@RGO hybrid was applied towards the electrochemical determination of caffeic acid (CA) in various food samples. The ZnS NPs@RGO hybrid modified electrode (GCE) exhibited an excellent electrocatalytic performance towards caffeic acid detection and determination, when compared to other modified electrodes. Therefore, the electrochemical sensing performance of the fabricated and nanocomposite modified electrode was significantly improved owing to the synergistic effect of ZnS NPs and RGO catalyst. Furthermore, the hybrid materials provide highly active electro-sites as well as rapid electron transport pathways. The proposed electrochemical caffeic acid sensor produces a wide linear range of 0.015-671.7 µM with a nanomolar level detection limit (3.29 nM). In addition, the real sample analysis of the proposed sensor has applied to the determination of caffeic acid in various food samples.