Fabrication of copper tungstate nanoparticles on screen printed carbon electrode: A disposable strip for the electrochemical detection of the food additive tertiary Butylhydroquinone.

Food additives enhance sensory pleasure and improve marketability in food product formulations, yet their potential health risks are highly consequential. Tertiary butylhydroquinone (TBHQ), in this regard, has a controversial reputation owing to its neurotoxic effects, which include convulsions and other chronic issues. This situation underscores the need for an advanced electrochemical sensing platform. The current study advocates the utilization of copper tungstate nanoparticles to enhance the sensitivity, selectivity, and efficiency in TBHQ detection, thus addressing the challenges posed by the excessive use of additives and safeguarding the integrity of the food supply chain. Hydrothermally synthesized CuWO4 nanoparticles exhibited superior physicochemical and morphological characteristics, bringing about wide linear response ranges (0.01 to 789 µM), high selectivity, excellent anti-interference capabilities, and a low detection limit of 0.9 nM (S/N = 3). The CuWO4 modified screen printed carbon electrode (SPCE) presents promising recovery ranges in food samples, facilitating real-time monitoring and streamlining the quality assessment of food additives.

Emerging carbonate anion intercalated- ZnCr-layered double hydroxide/vanadium carbide nanocomposite: A electrochemical sensor for diethofencarb fungicide monitoring.

Diethofencarb (DFC) is widely used in agriculture to fight against plant fungal attacks and enhance food crop production. On the other hand, the National food safety standard has set the overall maximum residual limit of DFC to be 1 mg/kg. Hence it becomes essential to limit their usage, and it is vital to quantify the amount of DFC present in real-life samples to safeguard the health and environmental well-being. Here, we introduce a simple hydrothermal procedure for preparing vanadium carbide (VC) anchored by ZnCr-LDH. The sustainably designed electrochemical sensor for the detection of DFC portrayed high electro-active surface area, conductivity, rapid-electron transport ratio, and high ion diffusion parameters. The obtained structural and morphological information confirms the enriched electrochemical activity of the ZnCr-LDH/VC/SPCE towards DFC. The ZnCr-LDH/VC/SPCE electrode has displayed exceptional characteristics with DPV resulting in a vast linear response (0.01-228 µM), and lower LOD (2 nM) with high sensitivity. Real-sample analysis was carried out to demonstrate the specificity of the electrode with an acceptable recovery in both water (±98.75-99.70%) and tomato (±98.00-99.75%) samples.

Nanoengineered disposable sensor fabricated with lanthanum stannate nanocrystallite for detecting animal feed additive: Ractopamine.

Ractopamine (RA) has been at the forefront of feed additives as a nutrient repartitioning mediator that recuperates the growth rate, decreases animal fat, and guarantees food safety. However, inappropriate and abusive usage of RA to enhance economic efficiency can negatively impact the environment-animal-human interactions. Therefore, the call for monitoring and quantifying RA is highly desired. In this work, the potentiality of La2Sn2O7 as an electrode modifier on the surface of the portable screen-printed carbon electrode (SPCE) was examined for its precision, disposability, and ability to detect RA. The superior electrocatalytic activity of the fabricated La2Sn2O7/SPCE fortifies its standpoints by displaying a wide linear working range of 0.01-501.2 µM, an enhanced sensitivity, a better stability, a lower LOD of 0.86 nM, and an increased selectivity toward the detection of RA. Furthermore, the investigation of the constructed electrochemical sensor with real-time food samples underpins its practicality and feasibility.

Deep Eutectic Solvent-Assisted Synthesis of a Strontium Tungstate Bifunctional Catalyst: Investigation on the Electrocatalytic Determination and Photocatalytic Degradation of Acetaminophen and Metformin Drugs.

In this work, we propose a modified solid-state approach for the sustainable preparation of a SrWO4 bifunctional catalyst using thymol-menthol-based natural deep eutectic green solvents (NADESs). Various spectroscopic and morphological techniques analyzed the as-synthesized SrWO4 particles. Acetaminophen (ATP) and metformin (MTF) were selected as the model drug compounds. The electrochemical detection and photocatalytic degradation of ATP and MTF upon ultraviolet-visible (UV-vis) light irradiation in the presence of as-prepared SrWO4 particles as an active catalyst are examined. The present study displayed that the proposed catalyst SrWO4 has enhanced catalytic activity in achieving the optimum experimental conditions, and linear ranges of ATP = 0.01-25.90 µM and MTF = 0.01-25.90 µM, a lower limit of detection (LOD) value (ATP = 0.0031 µM and MTF = 0.008 µM), and higher sensitivity toward ATP and MTF determination were obtained. Similarly, the rate constant was found to be k = ATP = 0.0082 min-1 and MTF = 0.0296 min-1 according to the Langmuir-Hinshelwood model, benefitting from the excellent synergistic impact of the SrWO4 catalyst toward the photocatalytic degradation of the drug molecule. Hence, this work offers innovative insights into the applicability of the as-prepared SrWO4 bifunctional catalyst as an excellent functional material for the remediation of emerging pollutants in water bodies with a recovery range of 98.2-99.75%.

Eutectic solvent mediated synthesis of carbonated CoFe-LDH nanorods: The effect of interlayer anion (Cl-, SO42-, CO32-) variants for comparing the bifunctional electrochemical sensing application.

The unabated usage of priority anthropogenic stressors is a serious concern in the global environmental context. Pharmaceutical drugs such as furazolidone (FL) and nilutamide (NL) have far-reaching repercussions due to the presence of the reactive nitroaromatic moiety. Despite the widespread awareness regarding the dangers posed by nitroaromatic drugs, the promises to alleviate the environmental consequences of drug pollution are often unmet. Accordingly, implementing practices to monitor their presence in various media is a highly desirable, but challenging undertaking. With the advent of deep eutectic solvent-assisted synthesis, it has become possible to fabricate LDH-based sensor materials with minimal energy inputs in a sustainable and scalable manner. In this work, we have framed a series of CoFe-LDH electrocatalysts utilizing deep eutectic solvent-assisted hydrothermal strategies for the simultaneous detection of FL and NL. The CoFe-LDHs intercalated with three distinct anions, namely, (i) Cl-, (ii) SO42-, and (iii) CO32- are compared so as to establish a relationship between anion intercalation and electrochemical activity. Amongst the prepared electrodes, the CF-LDH-ii/SPCE displays highly appreciable selectivity, linear response range (0.09-237.9 µM), low detetion limits (FL = 1.2 nM and NL = 3.8 nM), high sensitivity (FL = 29.71 µA µM⁻1 cm⁻2 and NL = 19.29 µA µM⁻1 cm⁻2), good reproducibility and repeatability towards FL and NL in water and urine samples. Thus, with tailored gallery anions, the proposed electrocatalyst establishes enhanced electrocatalytic performance for the real-time analysis of pharmaceutical contaminants.

Construction of ANbO3 (A= Na, K)/f-carbon nanofiber composite: Rapid and real-time electrochemical detection of hydroxychloroquine in environmental samples.

Hydroxychloroquine (HCQ) is a significant viral resistant drug widely acknowledged for its immunomodulatory and anti-inflammatory activities. To minimize the impact of HCQ residues on environmental pathways, exploring control measures is vital. In this regard, electrochemical sensing of HCQ using well-structured functional materials is advantageous. This work aims to provide an economical and sustainable route for the synthesis of ANbO3 (A = Na,K) perovskites via a thymol-menthol-based natural deep eutectic solvent. The as-synthesized NaNbO3 and KNbO3 are pinned to functionalized carbon nanofibers (f-CNF) via an ultrasonication approach. Benefitting from the synergistic effect of rapid electron transfer and improved surface area, enhanced electrochemical activity for NaNbO3@f-CNF/GCE is achieved. The fabricated NaNbO3@f-CNF displays a LOD (DPV = 0.01 µM, i-t = 0.007 µM), wide dynamic range (DPV = 0.09-22.5 µM, i-t = 0.006-35 µM), outstanding selectivity, and reproducibility, proving feasible in real-time analysis with good recovery rates (±97.67-99.81%). The NADES-mediated preparation of perovskites evades the incorporation of traditional toxic solvents and yields atom-efficient ANbO3 (A = Na,K) associated with green solvent templates. This validates the sustainable fabrication of electrode materials with reduced energy stipulations for detecting hazardous drug pollutants in the ecosystem.

In Situ Synthesis of a Bismuth Vanadate/Molybdenum Disulfide Composite: An Electrochemical Tool for 3-Nitro-l-Tyrosine Analysis.

The quantification of 3-nitro-l-tyrosine (NO2-Tyr), an in vivo biomarker of nitrosative stress, is indispensable for the clinical intervention of various inflammatory disorders caused by nitrosative stress. By integrating the unique features of BiVO4 and MoS2 with matching bandgap energies, electrode materials with amplified response signals can be developed. In this regard, we introduce a hydrothermally synthesized bismuth vanadate sheathed molybdenum disulfide (MoS2@BiVO4) heterojunction as a highly sensitive electrode material for the determination of NO2-Tyr. Excellent electrochemical behavior perceived for the MoS2@BiVO4 augments the performance of the sensor and allows the measurement of NO2-Tyr in biological media without any time-consuming pretreatments. The synergistic interactions between BiVO4 and MoS2 heterojunctions contribute to low resistance charge transfer (Rct = 159.13 Ω·cm2), a reduction potential Epc = -0.58 V (vs Ag/AgCl), and a good response range (0.001-526.3 µM) with a lower limit of detection (0.94 nM) toward the detection of NO2-Tyr. An improved active surface area, reduced charge recombination, and high analyte adsorption contribute to the high loading of the biomarker for improved selectivity (in the presence of 10 interfering compounds), operational stability (1000 s), and reproducibility (six various modified electrodes). The proposed sensor was successfully utilized for the real-time determination of NO2-Tyr in water, urine, and saliva samples with good recovery values (±98.94-99.98%), ascertaining the reliability of the method. It is noteworthy that the electrochemical activity remains unaffected by other redox interferons, thus leading to targeted sensing applications.

Surfactant-Assisted Synthesis of Praseodymium Orthovanadate Nanofiber-Supported NiFe-Layered Double Hydroxide Bifunctional Catalyst: The Electrochemical Detection and Degradation of Diphenylamine.

Physiological storage disorders are caused by ineffective post-harvest handling of horticultural crops, particularly fruits. To address these post-harvest concerns, diphenylamine (DPAH•+) is widely used as a preservative to prevent fruit degradation and surface scald during storage around the world. Humans are negatively affected by the use of high concentrations of DPAH•+ because of the various health complications related to its exposure. As a result, accurate detection and quantification of DPAH•+ residues in treated fruits are critical. Rare earth metal orthovanadates, which have excellent physical and chemical properties, are potential materials for electrochemical sensors in this area. Herein, we present a simple and direct ultrasonication technique for the surfactant-assisted synthesis of praseodymium orthovanadate (PrVO4 or PrV) loaded on nickel iron layered double hydroxide (NiFe-LDH) synthesized with deep eutectic solvent assistance, as well as its application as an effective catalyst in the detection and degradation of DPAH•+ in fruits and water samples. The current work presents supreme electrochemical features of a PrV@NiFe-LDH-modified screen-printed carbon electrode (SPCE) where cetyltrimethylammonium bromide (CTAB) surfactant-driven fabrication of PrV directs the formation of highly qualified engineered structures and the deep eutectic solvent based green synthesis of NiFe-LDH creates hierarchical lamellar structures following the principles of green chemistry. PrV and NiFe-LDH combine to produce a synergistic effect that improves the number of active sites, charge transfer kinetics, and electronic conductivity. Differential pulse voltammetry analysis of PrV@NiFe-LDH/SPCE reveals a dynamic working range (0.005-226.26 µM), increased sensitivity (133.13 µA µM-1 cm-2), enhanced photocatalytic activity, and low detection limit (0.001 µM), which are considered significant when compared with the former reported electrodes in the literature for the determination of DPAH+ for its real-time applications.

Well-Designed Construction of Yttrium Orthovanadate Confined on Graphitic Carbon Nitride Sheets: Electrochemical Investigation of Dimetridazole.

Antibiotics are the most important drugs for people and animals to fight bacterial illnesses. Overuse of antibiotics has had unintended consequences, such as antibiotic resistance and ecosystem eradication owing to toxic chemical discharge, which have a negative influence on the biome. Herein, we report the synthesis of a hollow ellipsoid-shaped yttrium vanadate/graphitic carbon nitride (YVO4@CN) nanocomposite by a hydrothermal approach followed by a sonochemical method for the effective detection of dimetridazole (DMZ). The synergic and coupling effect between both the phases offer non-linear cumulative ramifications which can positively enhance the individual properties of the materials under consideration. This positive hybrid effect increases the conductivity, shortens the ion-diffusion pathway, enhances the electron/ion transportation, and provides more active sites and electron-conducting channels. The accurate optimization of the experimental conditions proposes good electrocatalytic activity for the YVO4@CN catalyst, exhibiting a good response toward DMZ detection. It reveals an extensive linear concentration range (0.001-153.3 and 176.64-351.6 µM), a low detection limit (0.8 nM), higher sensitivity (4.98 µA µM-1 cm-2), appreciable selectivity, increased operational stability (2200 s), and good cycle stability (60 cycles). The electrochemical performance of YVO4@CN indicates its practical application in real-time sample analysis of several families of nitroimidazole drugs.

Toward the Development of Disposable Electrodes Based on Holmium Orthovanadate/f-Boron Nitride: Impacts and Electrochemical Performances of Emerging Inorganic Contaminants.

Rare-earth metal orthovanadates have great technological relevance in the family of rare-earth compounds owing to their excellent physical and chemical properties. A significant number of studies have been carried out on this class of compounds to exploit their electrochemical properties in virtue of variable oxidation states. But holmium vanadate (HoV) and its morphology selective synthesis have not been considered, which can have potential applications similar to the rest of the family. In this work, we propose the synthesis of superior architectures of HoV with a functionalized boron nitride (f-BN) nanocomposite. The synergistic effect between HoV and f-BN can have a positive effect on the physical characteristics of the nanocomposite, which can be explored for its electrochemical capacity. Here, HoV incorporated with f-BN is explored for the electrochemical detection of Hg2+ ions, which is known for its toxicity-induced environmental health hazards. The structural and compositional revelation reveals higher conductivity and faster electron transfer in the composite, which facilitates a wide working range (0.02-53.8 and 64.73-295.4 µM), low limit of detection (5 nM), higher sensitivity (66.6 µA µM-1 cm-2), good selectivity over 10-fold higher concentration of other interfering compounds compared to Hg2+ ion concentration, and good cycles stability (30 segments) toward Hg2+ ion detection. This also envisages the morphology selective synthesis and utilization of other rare-earth metals, whose electrochemical capacities are unexplored.

Synergy of the LaVO4/h-BN Nanocomposite: A Highly Active Electrocatalyst for the Rapid Analysis of Carbendazim.

In the field of agriculture fungicides are vital, providing the most important ecosystem service for food production. The widespread use of these chemicals can significantly lead to various ecotoxicological threats with adverse effects, such as environmental changes, microbial resistance, and phytotoxicity. Electrochemical sensors offer enormous potential for the identification and monitoring of hazardous substances in accordance with their constructive characteristics, namely, precision, accuracy, sensitivity, and selectivity, over traditional analytical techniques. Here, we thus report the synthesis of the lanthanum vanadate/hexagonal boron nitride (LaV/h-BN) composite for the electrochemical determination of carbendazim (CZ), which is a widely used fungicide for disease management with critical risks associated with its overexposure. The combination of LaV and h-BN accelerates the formation of active sites, facilitating faster charge transfer and higher electronic conductivity. The synergistic effects greatly improve the preference of the modified electrode with increased sensitivity, a lower limit of detection, and wide linear responses toward CZ detection. The existence of variable oxidation states in the orthovanadate together with the unique properties of h-BN mark LaV/h-BN as an advanced material for specific applications in the family of rare-earth metal orthovanadate. Also, the deep eutectic solvent-assisted synthesis of the material creates an environmentally efficient system with reduced energy requisites to allow for applications in effective environmental monitoring.

Integration of samarium vanadate/carbon nanofiber through synergy: An electrochemical tool for sulfadiazine analysis.

Antibiotic pollution causes worldwide concern due to its more apparent consequences, namely antibiotic resistance and destruction of the environment. Extensive use of antibiotics in human and veterinary drugs releases a significant amount of toxins into the sphere of living matter, causing adverse ecological impacts. This requires the design of new analytical protocols for the effective mitigation and monitoring of hazardous pharmaceutical products to reduce the environmental burden. Therefore, we present here the hydrothermal synthesis of samarium vanadate/carbon nanofiber (SmV/CNF) composite for the determination of sulfadiazine (SFZ). The synergistic effect arising from the combination of SmV and CNF accelerates charge transfer kinetics along with the creation of more surface-active sites that benefit effective detection. The structural and compositional disclosure indicates the high purity and superior attributes of the composite material that possesses the ability to improve catalytic performance. The proposed SmV/CNF sensor exhibits important static characteristics such as wide linear response ranges, low detection limit, high sensitivity and selectivity, and increased stability. To the best of our knowledge, this is the first report on the electrochemical performance of SmV/CNF, establishing its potential application in real-time analysis of environmentally hazardous contaminants.

Cobalt molybdate nanorods decorated on boron-doped graphitic carbon nitride sheets for electrochemical sensing of furazolidone.

A nanorod-like structured CoMoO4 embedded on boron doped-graphitic carbon nitride composite (CoMoO4/BCN) has been developed by a simple sonochemical method for electrochemical detection of furazolidone (FUZ). Interestingly, the impedance of CoMoO4/BCN fabricated screen-printed carbon electrode (SPCE) possesses a lower resistance charge transfer (Rct), which favors superior electrochemical detection of FUZ. Such CoMoO4/BCN/SPCE exhibits an ultralow detection limit of 1.6 nM with a concentration range of 0.04-408.9 µM, and high sensitivity of 11.6 µA µM-1 cm-2 by DPV method. In addition, biological and water samples were used for demonstration of practical application of CoMoO4/BCN/SPCE towards electrochemical detection of FUZ, and the result exhibits a satisfactory recovery.Graphical abstract.

Deep eutectic solvent-based manganese molybdate nanosheets for sensitive and simultaneous detection of human lethal compounds: comparing the electrochemical performances of M-molybdate (M = Mg, Fe, and Mn) electrocatalysts.

Potentially hazardous chemical contaminants endanger the environment and human well-being, challenging scientists and policy makers to develop holistic alternative approaches for remediation. The addition or accumulation of these chemicals can have a series of far-reaching consequences and have direct and indirect effects at multiple levels of ecological organization. Therefore, the development of a sensitive tool for the comprehensive evaluation of chemical concentrations is highly relevant. Herein, we thus report the simultaneous electrochemical detection of highly toxic hydroquinone (HQ), Hg2+, and nitrite (NO2-) compounds using nanostructured metal molybdate (M = Mg, Fe and Mn) catalysts. These functional nanomaterials are synthesized using a deep eutectic solvent (DES) modified hydrothermal method that provides sustainable aspects and energy efficient synthesis strategies. Choline chloride (ChCl)-urea DES used in this study exhibits an all-in-one behaviour by simultaneously acting as a template, reducing agent, and homogeneous means for stabilizing metal ions. This stimulates the fabrication of hierarchical structures of metal molybdates with high surface activities that cause their remarkable properties with minimal waste generation. The structural, morphological, catalytic, and electrochemical capacities of the as-synthesized MgMoO4, Fe2(MoO4)3, and MnMoO4 materials are explored through various techniques and comparatively, MnMoO4 presents superior characterization features such as a reduced particle size, increased surface area and hierarchical architectures. Owing to the exceptional physicochemical attributes, the MnMoO4 modified glassy carbon electrode (GCE) demonstrates superior electrochemical activities towards the individual and simultaneous detection of HQ, Hg2+, and NO2-. Well-defined and separate peaks are observed for the simultaneous detection of HQ, Hg2+, and NO2- which is influenced by the binding energies of these pollutants. Furthermore, the modified electrode exhibits a high sensitivity of 23.8, 17.7 and 10.2 µA µM-1 cm-2 with a limit of detection (LOD) of 0.026, 0.05, and 0.01 µM for HQ, Hg2+, and NO2- respectively under ideal conditions. Also, the reproducibility and anti-interference ability reinforce the application potential of the MnMoO4 modified electrode for the simultaneous electrochemical detection of HQ, Hg2+, and NO2- in real samples with better recoveries, thus assessing the effect of these hazardous chemicals on humanity.

Structural, Magnetic, Electrical and Photo-Fenton Properties of Copper Substituted Strontium M-Hexagonal Ferrite Nanomaterials via Chemical Coprecipitation Approach.

Copper substituted strontium ferrite nano spinels were synthesized by facile chemical coprecipitation method. Structural properties of all the nano materials were examined using Powder X-ray Diffraction of size ranging 22-50 nm and High Resolution Transmission Electron Microscopy which further revealed the formation of hexagonal spinel structure. The analysis of FT-IR spectra of all the samples confirmed the formation of M-O bond with spinel structure having characteristic peaks at 422 cm-1 and 586 cm-1. All the samples were subjected to dielectric studies at room temperature. A quite narrow band gap around 1.5-1.6 eV for all the samples indicates that these ferrites can behave as visible light photocatalysts. The as synthesized nano spinels were proposed to be promising heterogeneous Photo-Fenton catalysts under visible light for the degradation of organic pollutants. The photo catalytic degradation results revealed 94% degradation for all the prepared nano catalysts. The materials displayed remarkable photo-stability with recyclability up to five consecutive cycles. VSM studies of the materials exhibited weak ferromagnetic property with high surface area. Therefore, these magnetic materials presented no significant loss in activity specifying an exceptional capacity of ferrites to remove organic pollutants from wastewater.