One-step sonochemical synthesis of 1D β-stannous tungstate nanorods: An efficient and excellent electrocatalyst for the selective electrochemical detection of antipsychotic drug chlorpromazine

Development and validation of a QuEChERS-HPLC-DAD method using polymer-functionalized melamine sponges for the analysis of antipsychotic drugs in milk

The prohibition of antipsychotic drugs in animal foodstuffs has raised significant concerns. In this study, a novel matrix purification adsorbent comprising a polymer (polyaniline and polypyrrole)-functionalized melamine sponge (Ms) was employed for the high performance liquid chromatography-diode array detector (HPLC-DAD) detection of three phenothiazines (chlorpromazine, thioridazine, and promethazine), and a tricyclic imipramine in milk. The as-prepared functionalized Ms was characterized using scanning electron microscopy, Fourier transform infrared spectroscopy, and water contact angle measurements. Excellent linearity with a coefficient of determination (R2) of 0.999 was achieved for all drugs within the concentration range of 0.01-47.00 μg mL-1. The recoveries of the four analytes ranged from 92.1 % to 106.9 % at the three spiked levels. These results demonstrate the successful application of the proposed method for the determination of the four drugs. Cost-effective polymer-functionalized Ms is a viable alternative for matrix purification, enabling rapid determination of drug residues in diverse food samples.

An innovative experimental and mathematical approach in electrochemical sensing for mapping a drug sensor landscape

Our study delves into the examination of an electrochemical sensor through both experimentation and mathematical analysis. The sensor demonstrates the ability to identify a specific antipsychotic medication, namely Chlorpromazine Hydrochloride (CPH), even at incredibly low concentrations, reaching the picomolar level. The identification process relies on the utilization of a Glassy Carbon Electrode (GCE) that has been modified with a ceria-doped zirconia (CeO2/ZrO2) nanocomposite. The nanocomposite was synthesized using the co-precipitation technique and extensively characterized through various analytical methods. It is crucial to detect the presence of CPH as an overdose can result in hyperactivity and severe bipolar disorders among both children and adults. The average size of the nanocomposite was estimated to be 10 nm. The electrode surface area after CeO2/ZrO2 modification of the GCE was found to be 0.059 cm2, which was significantly higher than the electrode surface area of the bare GCE (0.0307 cm2). The limit of detection and limit of quantification for CPH were calculated to be 99.3 pM and 3.010 nM, respectively, with the linear dynamic range of CPH detection found to be between 0.10 and 1.90 μM. The modified sensor electrode was tested on human urine samples with good recoveries and exhibited high selectivity, repeatability, reproducibility, and long-term stability. The experimental voltammograms and the simulated stochastic voltammograms exhibited a fair amount of agreement. Examination of the experimental findings alongside analytical and numerical solutions enables a comprehensive analysis of the factors influencing the outcome of electrochemical measurements. The precise findings can be leveraged for the development of efficient sensing devices for medical diagnostics and environmental monitoring.

Design of sonochemical assisted synthesis of Zr-MOF/g-C3N4-modified electrode for ultrasensitive detection of antipsychotic drug chlorpromazine from biological samples

The rapid fabrication is described of binary electrocatalyst based on a highly porous metal-organic framework with zirconium metal core (Zr-MOF) decorated over the graphitic carbon nitride (g-C3N4) nanosheets via facile ultrasonication method. It is used for the robust determination of antipsychotic drug chlorpromazine (CLP) from environmental samples. The electrochemical behaviour of 2D Zr-MOF@g-C3N4 was characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) studies. The crystalline and porous nature of the composite was characterized by XRD and SEM analysis. The functional groups and surface characteristics were investigated by FT-IR, Raman and XPS. The major electrochemical properties of the Zr-MOF@g-C3N4 composite towards CLP detection were analyzed by CV, chronocoulometric (CC), chronoamperometric (CA) and differential pulse voltammetry (DPV) techniques. The composite exhibits a low detection limit (LOD) of 2.45 nM with a linear range of 0.02 to 2.99 µM and attractive sensitivity for CLP. The sensor system shows higher selectivity towards the possible interferences of CLP drug and exhibits better repeatability and stability. Finally, the fabricated sensor system shows a high recovery range varying from 96.2 to 98.9% towards the real samples. The proposed electrochemical probe might be a promising alternative to the prevailing diagnostic tools for the detection of CLP.

Hybrid structures of cobalt-molybdenum bimetallic oxide embedded in flower-like molybdenum disulfide for sensitive detection of the antibiotic drug nitrofurantoin

Excessive residues of nitrofurantoin (NFT) can cause serious contamination of water bodies and food, and potential harm to ecosystems and food safety. Given that, rapid and efficient detection of NFT in real samples is of particular importance. MoS₂ is a promising electrochemical material for this application. Here, MoS₂ was modulated by Metal-organic framework through the interfacial microenvironment to enhance the catalytic activity and carbonized to form Co₂Mo₃O₈ nanosheets with high electrical activity. The resulting Co₂Mo₃O₈/MoS₂ hybrid structure can be used to prepare highly sensitive NFT electrochemical sensor. The Co₂Mo₃O₈/MoS₂@CC electrochemical sensor exhibits strong electrochemical properties due to its fast electron transfer, excellent electrical conductivity, abundant defect sites, and high redox response. Based on this, this electrochemical sensor exhibited excellent electrocatalytic activity for NFT with a wide linear detection range, low detection limit, and high sensitivity. Moreover, the electrode was successfully applied to detect NFT in milk, honey, and tap water, strongly confirming its potential in real samples. This work could furnish the evidence for interfacial microenvironmental regulation of MoS₂, and also offer a novel candidate material for NFT sensing.

Application of electrochemical sensors based on nanomaterials modifiers in the determination of antipsychotics

At present, the content of antipsychotics in samples is always analyzed by traditional detection methods, including mass spectrometry (MS), spectrophotometry, fluorescence, capillary electrophoresis (CE). However, conventional methods are cumbersome and complex, require a large sample volume, many pre-processing steps, long analysis cycles, expensive instruments, and need well-trained detection capabilities personnel. In addition, patients with schizophrenia require frequent and painful blood collection procedures, which adds additional treatment costs and time burdens. In view of these factors, electrochemical methods have become the most promising candidate technology for timely analysis due to their low cost, simple operation, excellent sensitivity and specificity. As we all know, nanomaterials play an extremely important role in electrochemical sensing applications. As the sensor modifiers, nanomaterials enable electrochemical analysis to overcome the time-consuming and labor-intensive shortcomings of traditional detection methods, and greatly reduce the research cost. Nanomaterials modified electrodes can be used as sensors to determine the concentration of antipsychotics in organisms quickly and accurately, which is a bright spot in the application of nanomaterials. The combination of different nanomaterials can even form a nanocomposite with a synergistic effect. This paper firstly reviews the application of nanomaterials-modified sensors on the basis of research in the past ten years, reviews the use of nanomaterial-modified sensors to quickly and accurately determine the concentration of antipsychotics in biological samples, and demonstrates a new idea of using nanomaterials sensors for drug monitoring and determination. At the end of this review, a brief overview is given of the limitations and the future prospects of nanomaterial sensors for the determination of antipsychotics concentrations.

Strontium tungstate-modified disposable strip for electrochemical detection of sulfadiazine in environmental samples

Rapid-monitoring of drugs has attracted tremendous consideration owing to robust global demand for cost-effective and high effectiveness. Binary metal oxides with various morphology have been reported as electrodes for electrochemical sensor to fulfilling the clinical and enviromental requirements. In this study, strontium tungstate (SrWO₄) nanoflakes have been successfully prepared via the facile sonochemical method for the first time. The characteristics of as-prepared SrWO₄ are systematically measured by various analytical and spectroscopic methods. The SrWO₄ nanoflakes are utilized to modify the electrochemical electrode for the sulfadiazine (SDZ) determination. The SrWO₄ modified electrode possesses excellent electrocatalytic activity and high recognition capability for the electrochemical detection of SDZ. Impressively, the as-fabricated SrWO₄ modified electrode attainted lowest oxidation peak at +0.93 V (vs Ag/AgCl₂) with the limit of detection of 0.009 μM, the sensitivity of 0.123 µA µM^-1 cm² and linear detection range of 0.05-235 μM. The enhanced performance of proposed SrWO₄-based sensors could be attributed to the catalytic effect, large surface area, good electrical conductivity and physicochemical nature. Notably, the electrocatalytic performances of the SDZ sensors are good as compared to the previous literature, indicating the significance of the newly designed SrWO₄ modified electrode. The real-sample diagnosis by the SDZ detection in environmental sample demonstrates the proposed SrWO₄-based sensors with good recovery range.

A Versatile and Ultrasensitive Electrochemical Sensing Platform for Detection of Chlorpromazine Based on Nitrogen-Doped Carbon Dots/Cuprous Oxide Composite

The excessive intake of chlorpromazine (CPZ) adversely affects human health profoundly, leading to a series of severe diseases such as hepatomegaly and dyskinesia. The rapid and precise detection of CPZ in real samples is of great significance for its effective surveillance. Herein, a versatile and sensitive electrochemical sensor was developed for the detection of antipsychotic drug CPZ based on a Nafion (Nf)-supported nitrogen-doped carbon dots/cuprous oxide (N-CDs/Cu₂O) composite. The as-synthesized N-CDs/Cu₂O composite was systematically characterized using various physicochemical techniques. The developed composite-based sensor displayed excellent performance towards CPZ determination in a dynamic linear range of 0.001-230 µM with the detection limit of 25 nM. Remarkably, the developed sensor displayed good performance in terms of sensitivity and selectivity. Furthermore, good anti-interference properties toward CPZ determination were attained despite the presence of highly concentrated interfering compounds. Therefore, this composite could be a notable potential modifier to enhance electrocatalytic activity onto the surface of the electrode. Finally, N-CDs/Cu₂O/Nf-based sensor was effectively applied for quantification of CPZ in human urine and pharmaceutical formulation samples.

Design and Construction of the Gadolinium Oxide Nanorod-Embedded Graphene Aerogel: A Potential Application for Electrochemical Detection of Postharvest Fungicide

The rapid development of electrochemical sensors holds great promise to serve as next generation point-of-care safety devices. However, the practical performances of electrochemical sensors are cruelly limited by stability, selectivity, and sensitivity. These issues have been well addressed by introducing rational designs into the modified electrode for achieving the required performances. Herein, we demonstrate the gadolinium oxide nanorods embedded on the graphene aerogel (GdO NRs/GA) for a highly selective electrochemical detection of carbendazim (CDM). The GdO NRs/GA nanocomposite was characterized using X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, field emission gun scanning electron microscopy, transmission electron microscopy with elemental mapping, and energy-dispersive spectrometry. The GdO NRs/GA-modified electrode shows a much improved electrochemical performance compared to other electrodes. Interestingly, the GdO NRs are strongly anchored in the GA matrix, which provides a more sufficient pathway for the rapid electron and ion transportation. On the basis of these findings, our proposed sensor achieves a wide detection range from 0.01 to 75 μM with a correlation coefficient of 0.996 and a low detection limit of 3.0 nM. Most markedly, the real-time monitoring of the proposed electrochemical sensor was proved by the successful determination of CDM in environmental samples. Our research work has opened a novel way to the rationale for the construction of highly efficient practical electrochemical sensors.

Robust and selective electrochemical detection of antibiotic residues: The case of integrated lutetium vanadate/graphene sheets architectures

Lutetium vanadate (LuVO₄) is a promising material for electrochemical application owing to its good conductivity and electrocatalytic activity. Herein, we demonstrate a facile technique for the synthesis of a LuVO₄/ graphene sheet (GRS) nanocomposite where LuVO₄ is encapsulated with an ultrathin GRS to form a hierarchical structure (LuVO₄/GRS). The resulting hierarchical LuVO4/GRS architecture was characterized by several analytical and spectroscopic techniques. The resultant electrocatalyst shows superior electrochemical sensing for nitrofurantoin (NFT) with a low detection limit (0.001 μM), wide linear range (0.008-256.0 μM) and excellent sensitivity (1.709 μA μM^-1 cm^-2). It has been demonstrated that the enhanced electrocatalytic performance of LuVO₄/GRS nanocomposite is due to their excellent electrical conductivity, suitable surface area, high redox reaction and large number of electron transport. In addition, the LuVO₄/GRS nanocomposite exhibited excellent response towards NFT detection with adequate reproducibility, good repeatability, long-term stability and excellent selectivity over its structural analogs and common interferents. Furthermore, the practical applicability of the proposed electrochemical sensor was successfully applied for determination of NFT in environmental samples with satisfactory results. The LuVO₄/GRS nanocomposite presented here can serve as a favorable candidate for developing electrochemical sensor and plays an important role in widespread fields.

Structural Insights on 2D Gadolinium Tungstate Nanoflake: A Promising Electrocatalyst for Sensor and Photocatalyst for the Degradation of Postharvest Fungicide (Carbendazim)

Gadolinium tungstate (Gd₂(WO₄)₃) has acquired much attention owing to its exclusive transport properties and excellent thermal and chemical stability. In this work, we demonstrate that two-dimensional (2D) gadolinium tungstate nanoflakes (GW Nfs) are synthesized by a coprecipitation method and represent novel architectures for efficient catalysis, which could be used in electrochemical sensing and photocatalytic degradation of the postharvest fungicide carbendazim (CBZ). The physicochemical properties of GW Nfs were studied by using XRD, Raman, TEM, EDX, and XPS, which show the formation of GW as a nanoflake-like structure with a well crystallized nature. The as-prepared GW Nfs revealed an admirable electrochemical response for CBZ detection with an LOD of 0.005 μM, a wide-ranging linear response of 0.02 to 40 μM, and a notable sensitivity of 0.39 μA μM^-1 cm^-2. Furthermore, the GW-Nf-modified electrode has a good recovery for CBZ in the study of real samples such as rice and soil washed water samples. Moreover, GW Nfs have a promising photocatalytic activity for CBZ degradation. The GW Nfs could degrade CBZ at greater than 98% efficiency and mineralize above 74% of the CBZ molecules in the presence of visible light irradiation with superior stability even after many cycles. Subsequently, the electrochemical and photocatalytic mechanisms were provided in detail.

Electrochemical sensing of nicotine using CuWO4 decorated reduced graphene oxide immobilized glassy carbon electrode

A novel and selective electrochemical sensing of nicotine is studied using copper tungstate decorated reduced graphene oxide nanocomposite (CuWO₄/rGO) nafion (Nf) immobilized GC electrode (GCE). The CuWO₄/rGO nanocomposite is synthesized using sonication method and characterized by HR-TEM (High resolution transmission electron microscopy), SEM (Scanning electron microscopy), FT-IR (Fourier transform infrared spectroscopy), SAED (Selected area of electron diffraction pattern), XRD (X-ray diffraction), Raman spectroscopy, Thermo gravimetric analysis (TGA) and EDX (Energy dispersive X-ray diffraction) techniques. The CuWO₄/rGO/Nf immobilized GCE shows better electrocatalytic response for the detection of nicotine as compared to bare GCE. A better selectivity and sensitivity is achieved using CuWO₄/rGO/Nf immobilized GCE to detect 0.1 µM nicotine in the presence of 100-fold excess concentrations of different interferents. The present CuWO₄/rGO/Nf immobilized GCE electrochemical sensor exhibits an ample range of sensing from 0.1 µM to 0.9 µM and the low detection limit is found to be 0.035 µM (S/N = 3). Comparable results are achieved for the determination of nicotine in various real samples such as cigarettes (Gold flake and Wills) and urine samples with improved recoveries.

Sonochemical synthesis of molybdenum oxide (MoO3) microspheres anchored graphitic carbon nitride (g-C3N4) ultrathin sheets for enhanced electrochemical sensing of Furazolidone

Present strategy introduce the sonochemical synthesis of molybdenum oxide (MoO₃) microspheres anchored graphitic carbon nitride (g-C₃N₄) ultrathin sheets as a novel electrocatalyst for the detection of Furazolidone (FU). TEM results revealed that MoO₃ are microspheres with an average size of 2 µM and the g-C₃N₄ seems like ultrathin sheets. Owing to their peculiar morphological structure, g-C₃N₄/MoO₃ composite modified electrode provided an enriched electroactive surface area (0.3788 cm²) and higher heterogeneous electron transfer kinetics (K°_eff = 4.91×10^-2 cm s^-1) than the other controlled electrodes. It is obviously observed from the voltammetric studies that the proposed sensor based on g-C₃N₄/MoO₃ composite can significantly improve the electrocatalytic efficiency towards the sensing of FU. Due to the excellent synergic effect of g-C₃N₄/MoO₃ composite, can detect the ultra-level FU with a limit of detection of 1.4 nM and a broad dynamic range of 0.01-228 µM, which surpassed the many previously reported FU sensors. Hence, the proposed sensor was successfully applied to sensing the FU in human blood serum, urine and pharmaceutical samples, gained an agreeable recoveries.