Sonochemically recovered silver oxide nanoparticles from the wastewater of photo film processing units as an electrode material for supercapacitor and sensing of 2, 4, 6-trichlorophenol in agricultural soil samples

Rare earth orthovanadate (REM-VO4; REM = Pr, Gd, and Sm)-based sensors for selective and simultaneous detection of furazolidone and metronidazole

Antibiotics are vital tools in the fight against bacterial infections, with furazolidone (FD) and metronidazole (MD) being widely used to target pathogens like G. lamblia and H. pylori. However, overuse of these antibiotics can lead to serious health complications, highlighting the urgent need for accurate, real-time detection of these drugs at precise levels. In this study, we explore the use of differential pulse voltammetry (DPV) for detecting FD and MD with high sensitivity, employing a dual detection method. To enhance detection, we developed a sensor using rare earth metal-based orthovanadates (REM-VO4, where REM = Pr, Gd, and Sm) as electrode modifiers. These materials offer exceptional surface control, boosting the sensor's sensitivity and selectivity. Among the different configurations, the SmVO4-modified glassy carbon electrode (SmV/GCE) stands out, demonstrating the lowest charge transfer resistance (Rct = 56.82 Ω) and the largest electrochemical surface area (A = 0.11 cm2). SmVO4's unique nanostructure, with its high electrochemically active surface area and hollow structure, is key to its impressive performance. This sensor not only provides the lowest limits of detection (0.0009 μM for FD and 0.0036 μM for MD individually, and 0.0015 μM and 0.0049 μM for simultaneous detection) but also shows excellent anti-interference, repeatability, and reproducibility. Furthermore, SmV/GCE has been successfully applied for real-time analysis of biological and environmental samples, offering recoveries between 97.33 to 99.60%, demonstrating its practical potential for precise antibiotic monitoring.

Cerium vanadate/functionalized carbon nanofiber composite for the electrochemical detection of nitrite

This study presents a facial and quick electrochemical sensor platform that offers remarkable water and food safety applications. The present work represents a study of the synthesis and characterization for efficient cerium vanadate (CeVO4) with a functionalized carbon nanofiber (f-CNF) decorated electrode, which is a highly effective electrode modifier for sensitive nitrite detection. The CeVO4 nanoparticles were synthesized using the facial hydrothermal technique, and a composite (CeVO4@f-CNF) was prepared using the sonication method. Afterward, the produced materials were confirmed with spectroscopic and microscopic analysis. The electrochemical behavior of nitrite was studied through cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The DPV analysis depicts an excellent linear range of 0.1-1033 μM and a promising detection limit of 0.004 μM for the proposed electrode. The CeVO4@f-CNF electrode was applied to detect nitrite in water and meat samples. The proposed electrochemical sensor attributes the significant results towards the detection of nitrite.

Multifunctional Ag2O/chitosan nanocomposites synthesized via sol-gel with enhanced antimicrobial, and antioxidant properties: A novel food packaging material

In this study, a single step in situ sol-gel method was used to syntheses nanocomposite films using chitosan (CS) as the basis material, with the addition of silver oxide nanoparticles (Ag2O) at several weight percentages (5 %, 10 %, and 15 % Ag2O/CS). The structural characteristics of Ag2O/CS films were investigated using a range of analytical techniques. The presence of the primary distinctive peaks of chitosan was verified using FTIR spectra analysis. However, a minor displacement was observed in these peaks due to the chemical interaction occurring with silver oxide molecules. XRD analysis demonstrated a significant increase in the crystallinity of chitosan when it interacted with metal oxide nanoparticles. Furthermore, it is believed that the interaction between silver oxide and the active binding sites of chitosan is responsible for the evenly dispersed clusters shown in the micrographs of the chitosan surface, as well as the random aggregations within the pores. EDS technique successfully identified the presence of distinctive silver signals within the nanocomposite material, indicating the successful absorption of silver into the surface of the polymer. The developed Ag2O/CS nanocomposite showed promising antibacterial activity against Gram-negative (Escherichia coli and Pseudomonas aeruginosa) and Gram-positive bacteria (Bacillus subtilis, Enterococcus faecalis and Staphylococcus aureus). Also, Ag2O/CS nanocomposite exhibited marked antifungal activity against Candida albicans, Aspergillus flavus, A. fumigatus, A. niger, and Penicillium chrysogenum. The antioxidant activity of the developed nanocomposite films was studied by ABTS radical scavenging. The highest antioxidant and antibacterial properties were achieved by including 15 % silver oxide into the chitosan. Therefore, our finding indicate that chitosan‑silver oxide nanocomposites exhibits significant potential as a viable material for application in several sectors of the food packaging industry.

Two-Dimensional CuMn-Layered Double Hydroxides: A Study of Interlayer Anion Variants on the Electrochemical Sensing of Trichlorophenol

Despite their diverse application profile, aromatic organochlorides such as 2,4,6-trichlorophenol (TP) are widely renowned for creating a negative toll on the balance of the ecosystem. Strict regulatory regimes are required to limit exposure to such organic pollutants. By deployment of a straightforward detection scheme, electrochemical sensing technology offers a competitive edge over the other techniques and practices available for pollutant monitoring. Here, we present a streamlined hydrothermal approach for synthesizing copper-manganese layered double hydroxide (CuMn-LDH) rods to be employed as electrocatalysts for detecting TP in various media. With a focused intention to leverage the full potential of the prepared CuMn-LDHs, the interlamellar region is configured using a series of intercalants. Further, a thorough comparative analysis of their structures, morphologies, and electrochemical performance is accomplished using various analytical techniques. The electrocatalytic oxidation ability of the CuMn-LDH toward TP molecules is markedly altered by incorporating various anions into the gallery region. The dynamic attributes of the developed sensor, such as a wide linear response (0.02-289.2 μM), a low detection limit (0.0026 μM), and good anti-interfering ability, acclaim its superior viability for real-time detection of TP with exceptional tolerance to the presence of foreign moieties. Hence, this work manifests that the nature of intercalants is a vital aspect to consider while designing LDH-based electrochemical probes to detect priority pollutants.

The Fabrication of a La2Sn2O7/f-HNT Composite for Non-Enzymatic Electrochemical Detection of 3-Nitro-l-tyrosine in Biological Samples

Reactive oxygen and nitrogen species (RONS), including 3-nitro-l-tyrosine, play a dual role in human health, inducing oxidative damage and regulating cellular functions. Early and accurate detection of such molecules, such as L-tyrosine in urine, can serve as critical biomarkers for various cancers. In this study, we aimed to enhance the electrochemical detection of these molecules through the synthesis of La₂Sn₂O₇/f-HNT nanocomposites via a simple hydrothermal method. Detailed structural and morphological characterizations confirmed successful synthesis, consistent with our expected outcomes. The synthesized nanocomposites were utilized as nanocatalysts in electrochemical sensors, showing a notable limit of the detection of 0.012 µM for the real-time detection of 3-nitro-l-tyrosine. These findings underscore the potential of nanomaterial-based sensors in advancing early disease detection with high sensitivity, furthering our understanding of cellular oxidative processes.

Facile synthesis of multifunctional zinc vanadate/polyaniline composite for photocatalytic degradation and supercapacitor applications

Multifunctional Zn₃V₂O₈/Polyaniline (ZnV/PANI) composite was prepared by in-situ oxidative polymerization method. The formation of ZnV and ZnV/PANI composite was proved by various characterization tools including such as FTIR, XRD, SEM, BET, VSM, TEM and XPS analysis. The average crystalline size calculated using Scherrer equation of ZnV and ZnV/PANI were found to be 45 nm and 92 nm respectively. From the Tauc plots the bandgap values (E_g) were found to be 2.4 eV and 2.0 eV for ZnV and ZnV/PANI respectively. The FE-SEM images clearly show the flakes incorporated cluster-like morphology. The BET surface area of ZnV and ZnV/PANI was found to be 22 m² g^-1 and 40 m² g^-1. The XPS results also confirm the successful formation of ZnV/PANI composite. The as-prepared samples were utilized as photocatalyst and electrode materials for energy applications. The ZnV/PANI composite showed an outstanding photocatalytic activity (94%) in the degradation of aqueous RhB dye under visible light irradiation. The optimum catalyst dosage for the degradation of 50 mL of 1 × 10^-5 M RhB dye aqueous solution was 50 mg. The Langmuir-Hinselwood (L-H) kinetic model proves that the photodegradation mechanism follows pseudo-first order kinetics. Further, the supercapacitive behavior of the ZnV/PANI composite was tested using cyclic voltammetry (CV), galvanostatic charge-discharge (GCD) techniques in 1 M KOH electrolyte at the potential window of 0-0.55 V. ZnV/PANI electrode displayed a specific capacitance (C_sp) of 664 F g^-1 at 1 A/g. The satisfactory performance of ZnV/PANI composite is mainly ascribed to the synergistic effect of ZnV-PANI matrixes with the occurrence of multiple electroactive sites in the composite. The cycling stability test proved that ZnV/PANI electrode material retained 92% of its initial capacitance even after 6000 GCD cycles at 2 A/g. The finding of this study will help to determine the most efficient and cost-effective method for the removal of dyes from textile industry wastewater and also as an effective material for supercapacitor applications.

Self-assembled nanorods with reduced graphene oxide as efficient nano-catalyst for dual modality sensing of hazardous phenolic compound

The modern development in the agricultural production has huge influential factors being highly beneficial and also includes some health hazards. Under the class of chlorophenols, 2,4,6-trichlorophenol is a widely used chemical which remains as a major pollutant in the environment. The detection of 2,4,6-trichlorophenol was initiated as a controlling measure to decrease the seriousness prevailing in the ecosystem. The electrochemical and UV-vis absorption sensing platform are simple and low-cost detection techniques with precise and sensitive analysis. Cadmium tin oxide integrated with the reduced graphene oxide was employed as a nanohybrid for the construction of the working electrode. The structural and morphological analysis confirmed the high degree of crystallinity of the nanocomposite with nanorod formation. The high surface area, with high charge carrier mobility, and increased electrical conductivity of the material boosted the 2,4,6-trichlorophenol detection. The active surface area was calculated to be 0.068 cm^-1, 0.089 cm^-1, 0.118 cm^-1 and 0.146 cm^-1 for all the modified electrodes. The resistance of the electrodes was about 91.4 Ω, 72.9 Ω, 48.8 Ω and 41.6 Ω. The linear range of 2,4,6-trichlorophenol was 0.019 μM-0.299 μM and 1.299 μM-1678.97 μM in electrochemical sensing and 10.99 μM-24.84 μM in UV detection. The obtained limit of detection with the formulation 3σ/SD was about 3.05 nM and 80 nM with sensitivity about 14.01 μA μM^-1 cm^-2. The real sample detection in environmental real samples showed good recovery results. The specific selectivity, good repeatability, reproducibility and stability analysis proves the good sensing parameters. Thus, the fabricated electrode is highly sufficient of sensing 2,4,6-trichlorophenol. These excellent features of the material can be applied for several other applications which will provide good performances.

Vanadium selenide decorated reduced graphene oxide nanocomposite: A co-active catalyst for the detection of 2,4,6 - Trichlorophenol

Transition metal chalcogenides (TMCs) have great potential in diverse electrochemical technologies owing to their unique characteristics. In the present work, we portray the design and synthesis of Vanadium selenide (V₂Se₉)/reduced graphene oxide (rGO) forming a two-dimensional (2D) hybrid nanocomposite via a simple hydrothermal method. The successfully synthesized nanocomposite underwent in-depth surface and morphological characterizations by XRD, Raman spectroscopy, XPS, TEM, STEM and its potential as an electro catalyst was investigated by using glassy carbon electrode (GCE) for the detection of 2,4,6-trichlorophenol (TCP). The structural features favored a high charge transfer ratio, high surface area as well as excellent conductivity and catalytic activity. The V₂Se₉/rGO/GCE modified electrode showed a low charge transfer resistance (R_ct) of 54.057 Ω cm², a decent detection limit (LOD) of 35.07 nM and a very high sensitivity of 22 μA μM^-1 cm^-2 in a working range of 0.001 μM-1150 μM. This is due to the active proton interaction, surface enhancement, and positive synergistic effect between rGO and V₂Se₉. The proposed sensor has good detection potential in agricultural soil, river water, fish, and beverage samples like wine and apple juice. The obtained results from our investigation would elucidate the application of the catalyst in electrochemical sensors.

An eco-friendly low-temperature synthetic approach towards micro-pebble-structured GO@SrTiO3 nanocomposites for the detection of 2,4,6-trichlorophenol in environmental samples

The low-temperature synthesis of the graphene oxide-wrapped perovskite-type strontium titanate nanocomposites (GO@SrTiO₃-NC) is reported for the electrochemical sensing of organochlorine pesticide 2,4,6-trichlorophenol (TCP) detection. The as-prepared GO@SrTiO₃ nanocomposites provide a large surface area, excellent conductivity, and active sites, which are more favorable to the catalysis of TCP. The synergistic effect between the GO and the perovskite SrTiO₃ results in the extended working range of 0.01 to 1.47 and 1.47 to 434.4 μM with a very low detection limit of 3.21 nM towards TCP detection. Moreover, the prepared sensor possessed good selectivity and long-term stability. Finally, the practical applicability of the sensor was tested in environmental samples of river water and soil, exhibiting adequate recovery values.

Tuning the efficiency of CoFe2O4@rGO composite by encapsulating Ag nanoparticles for the photocatalytic degradation of methyl violet dye and energy storage systems

Photocatalytic activity of the Ag NPs/CoFe2O4@rGO composite.