-
Analytica Chimica Acta Nov 2023The residues of pesticides and antibiotics have always been a major concern in agriculture and food safety. In order to provide a new method for the rapid detection of...
Sensitive fluorescent detection of phosmet and chlortetracycline in animal-derived food samples based on a water-stable Cd(II) chain-based zwitterionic metal-organic framework.
The residues of pesticides and antibiotics have always been a major concern in agriculture and food safety. In order to provide a new method for the rapid detection of organophosphorus pesticides and antibiotics, a novel Cd(II) chain-based zwitterionic metal-organic framework MOF 1 with high sensitivity fluorescence sensing performance was successfully synthesized. A series of researches showed that the water- and pH-stable bifunctional MOF 1 has a great ability to detect phosmet (PSM) and chlortetracycline (CTC) in water through fluorescence quenching effect, with high detection sensitivity, low detection limits (0.0124 μM and 0.0131 μM), short response time (40 s) and reusability. Practical application results revealed that MOF 1 could detect PSM and CTC in milk, beef, chicken and egg samples, with satisfactory recoveries (95.2%-103.7%). As a novel fluorescence probe, MOF 1, is known the first case that can detect PSM in animal-derived samples, and the first dual-function material capable of detecting PSM and CTC. Mechanism studies displayed that competitive absorption and photoinduced electron transfer clearly authenticate the high quenching performance of the material.
Topics: Animals; Cattle; Chlortetracycline; Metal-Organic Frameworks; Phosmet; Cadmium; Water; Organophosphorus Compounds; Pesticides; Anti-Bacterial Agents
PubMed: 37858547
DOI: 10.1016/j.aca.2023.341850 -
Environmental Science. Processes &... Dec 2023Phosmet is an organophosphorus insecticide widely used in agriculture to control a range of insects; recently, it was banned by the European Union in 2022 due to its...
Phosmet is an organophosphorus insecticide widely used in agriculture to control a range of insects; recently, it was banned by the European Union in 2022 due to its harmful effects. However, its environmental degradation and fate have not yet been evident. Thus, phosmet oxidation by HO˙ radicals was theoretically studied in this work using the DFT approach at the M06-2X/6-311++G(3df,3pd)//M06-2X/6-31+G(d,p) level of theory. Three different mechanisms were considered, including formal hydrogen transfer (FHT), radical adduct formation (RAF), and single electron transfer (SET). The mechanisms, kinetics, and lifetime were studied in the gas and aqueous phases, in addition to its ecotoxicity evaluation. The results show that FHT reactions were dominant in the gas phase, while RAF was more favourable in the aqueous phase at 298 K, while SET was negligible. The branching ratio indicated that H-abstractions at the methyl and the methylene groups were the most predominant, while the most favourable HO˙-addition was observed at the phosphorus atom of the dithiophosphate group. The overall rate constant values varied from 1.2 × 10 (at 283 K) to 1.40 × 10 M s (at 323 K) in the aqueous phase and from 6.29 × 10 (at 253 K) to 1.32 × 10 M s (at 323 K) in the gas phase. The atmospheric lifetime of phosmet is about 6 hours at 287 K, while it can persist from a few seconds to several years depending on the temperature and [HO˙] concentration in the aqueous environment. The QSAR-based ecotoxicity evaluation indicates that phosmet and its degradation products are all dangerous to aquatic organisms, although the products are less toxic than phosmet. However, they are generally developmental toxicants and mutagenicity-negative compounds.
Topics: Insecticides; Phosmet; Water; Organophosphorus Compounds; Oxidation-Reduction; Kinetics; Models, Theoretical; Hydroxyl Radical
PubMed: 37850503
DOI: 10.1039/d3em00325f -
Ophthalmic & Physiological Optics : the... Jan 2024This study used three-dimensional (3D) modelling to investigate scleral profiles in myopic eyes and compare them with emmetropic eyes. (Observational Study)
Observational Study
PURPOSE
This study used three-dimensional (3D) modelling to investigate scleral profiles in myopic eyes and compare them with emmetropic eyes.
METHODS
In this prospective observational study, the eyes of 151 participants were analysed using the corneoscleral profile module (CSP) of the Pentacam HR. Non-rotationally symmetrical ellipsoids were fitted to the anterior scleral sagittal height. Three radii were analysed, namely the nasal-temporal (Rx), superior-inferior (Ry) and anterior-posterior (Rz) orientations. Additionally, the area index (AI) and aspherical parameters (Qxy, Qxz and Qyz) of the anterior sclera-fitted ellipsoid (ASFE) were quantified.
RESULTS
The findings showed an increase in Rx (-0.349 mm/D), Ry (-0.373 mm/D), Rz (-1.232 mm/D) and AI (-36.165 mm /D) with increasing myopia. From emmetropia to high myopia, the vertical and horizontal planes of the anterior sclera became increasingly prolate (emmetropia, Qxz: 0.02, Qyz: 0.01; low myopia, Qxz: -0.28, Qyz: -0.28; high myopia, Qxz: -0.41, Qyz: -0.43). There were no significant differences in the coronal plane across the three groups (H = 2.65, p = 0.27). The anterior scleral shape of high myopes in the horizontal and vertical planes was more prolate than that of emmetropes and low myopes (Qxz, high myopes vs. low myopes: p = 0.03, high myopes vs. emmetropes: p < 0.001; Qyz, high myopes vs. low myopes: p = 0.04, high myopes vs. emmetropes: p < 0.001).
CONCLUSIONS
As the degree of myopia increased, non-uniform anterior scleral enlargement was observed. These findings provide a better understanding of the anterior segment with varying degrees of myopia.
Topics: Humans; Sclera; Phosmet; Myopia; Emmetropia; Prospective Studies
PubMed: 37811684
DOI: 10.1111/opo.13235 -
Journal of Materials Chemistry. B Oct 2023Conventional nanozyme-based pesticide detection often requires the assistance of acetylcholinesterase. In this work, a CuCeTA nanozyme was successfully designed for the...
Conventional nanozyme-based pesticide detection often requires the assistance of acetylcholinesterase. In this work, a CuCeTA nanozyme was successfully designed for the direct colorimetric detection of glyphosate. Direct detection can effectively avoid the problems caused by cascading with natural enzymes such as acetylcholinesterase. By assembling tannic acid, copper sulfate pentahydrate and cerium(III) nitrate hexahydrate, CuCeTA nanoflowers were prepared. The obtained CuCeTA possessed excellent peroxidase-like activity that could catalyze the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) to blue oxidized TMB in the presence of hydrogen peroxide. Glyphosate could effectively inhibit the peroxidase-like activity of CuCeTA while other pesticides (fenthion, chlorpyrifos, profenofos, phosmet, bromoxynil and dichlorophen) did not show significant inhibitory effects on the catalytic activity of CuCeTA. In this way, CuCeTA could be used for the colorimetric detection of glyphosate with a low detection limit of 0.025 ppm. Combined with a smartphone and imageJ software, a glyphosate test paper was designed with a detection limit of 3.09 ppm. Fourier transform infrared spectroscopy demonstrated that glyphosate and CuCeTA might be bound by coordination, which could affect the catalytic activity of CuCeTA. Our CuCeTA-based nanozyme system exhibited unique selectivity and sensitivity for glyphosate detection and this work may provide a new strategy for rapid and convenient detection of pesticides.
Topics: Peroxidase; Acetylcholinesterase; Colorimetry; Peroxidases; Coloring Agents; Pesticides; Glyphosate
PubMed: 37750214
DOI: 10.1039/d3tb01455j -
Foods (Basel, Switzerland) Sep 2023In modern agricultural practices, organophosphorus pesticides or insecticides (OPs) are regularly used to restrain pests. Their limits are closely monitored since their...
A Multi-Enzyme Cascade Response for the Colorimetric Recognition of Organophosphorus Pesticides Utilizing Core-Shell Pd@Pt Nanoparticles with High Peroxidase-like Activity.
In modern agricultural practices, organophosphorus pesticides or insecticides (OPs) are regularly used to restrain pests. Their limits are closely monitored since their residual hinders the capability of acetylcholinesterase (AChE) and brings out a threatening accumulation of the neurotransmitter acetylcholine (ACh), which affects human well-being. Therefore, spotting OPs in food and the environment is compulsory to prevent human health. Several techniques are available to identify OPs but encounter shortcomings like time-consuming, operating costs, and slow results achievement, which calls for further solutions. Herein, we present a rapid colorimetric sensor for quantifying OPs in foods using TMB as a substrate, a multi-enzyme cascade system, and the synergistic property of core-shell Palladinum@Platinum (Pd@Pt) nanoparticles. The multi-enzyme cascade response framework is a straightforward and effective strategy for OPs recognition and can resolve the previously mentioned concerns. Numerous OPs, including Carbofuran, Malathion, Parathion, Phoxim, Rojor, and Phosmet, were successfully quantified at different concentrations. The cascade method established using Pd@Pt had a simple and easy operation, a lower detection limit range of (1-2.5 ng/mL), and a short detection time of about 50 min. With an R value of over 0.93, OPs showed a linear range of 10-200 ng/mL, portraying its achievement in quantifying pesticide residue. Lastly, the approach was utilized in food samples and recovered more than 80% of the residual OPs.
PubMed: 37685251
DOI: 10.3390/foods12173319 -
Biosensors & Bioelectronics Oct 2023Conventional rapid detection methods are difficult to identify or distinguish various pesticide residues at the same time. And sensor arrays are also limited by the...
Conventional rapid detection methods are difficult to identify or distinguish various pesticide residues at the same time. And sensor arrays are also limited by the complexity of preparing multiple receptors and high cost. To address this challenge, a single material with multiple properties is considered. Herein, we first found that different categories of pesticides have diverse regulatory behaviors on the multiple catalytic activities of Asp-Cu nanozyme. Thus, a three-channel sensor array based on the laccase-like, peroxidase-like, and superoxide dismutase-like activities of Asp-Cu nanozyme was constructed and successfully used for the discrimination of eight kinds of pesticides (glyphosate, phosmet, isocarbophos, carbaryl, pentachloronitrobenzene, metsulfuron-methyl, etoxazole, and 2-methyl-4-chlorophenoxyacetic acid). In addition, a concentration-independent model for qualitative identification of pesticides has been established, and 100% correctness was achieved in the recognition of unknown samples. Then, the sensor array also exhibited excellent interference immunity and was reliable for real sample analysis. It provided a reference for pesticide efficient detection and food quality supervision.
Topics: Pesticides; Biosensing Techniques; Pesticide Residues; Peroxidase; Phosmet
PubMed: 37311405
DOI: 10.1016/j.bios.2023.115458 -
Spectrochimica Acta. Part A, Molecular... Nov 2023Pesticide active ingredients (AIs) are often applied with adjuvants to facilitate the stability and functionality of AIs in agricultural practice. The objective of this...
Pesticide active ingredients (AIs) are often applied with adjuvants to facilitate the stability and functionality of AIs in agricultural practice. The objective of this study is to investigate the role of a common non-ionic surfactant, alkylphenol ethoxylate (APEO), on the surface-enhanced Raman spectroscopic (SERS) analysis of pesticides as well as its impact on pesticide persistence on apple surfaces, as a model fresh produce surface. The wetted areas of two AIs (thiabendazole and phosmet) mixed with APEO were determined respectively to correct the unit concentration applied on apple surfaces for a fair comparison. SERS with gold nanoparticle (AuNP) mirror substrates was applied to measure the signal intensity of AIs with and without APEO on apple surfaces after a short-term (45 min) and a long-term (5 days) exposure. The limit of detection (LOD) of thiabendazole and phosmet using this SERS-based method were 0.861 ppm and 2.883 ppm, respectively. The result showed that APEO decreased the SERS signal for non-systemic phosmet, while increased SERS intensity of systemic thiabendazole on apple surfaces after 45 min pesticide exposure. After 5 days, the SERS intensity of thiabendazole with APEO was higher than thiabendazole alone, and there was no significant difference between phosmet with and without APEO. Possible mechanisms were discussed. Furthermore, a 1% sodium bicarbonate (NaHCO) washing method was applied to test the impact of APEO on the persistence of the residues on apple surfaces after short-term and long-term exposures. The results indicated that APEO significantly enhanced the persistence of thiabendazole on plant surfaces after a 5-day exposure, while there was no significant impact on phosmet. The information obtained facilitates a better understanding of the impact of the non-ionic surfactant on SERS analysis of pesticide behavior on and in plants and helps further develop the SERS method for studying complex pesticide formulations in plant systems.
Topics: Pesticides; Malus; Phosmet; Surface-Active Agents; Gold; Thiabendazole; Metal Nanoparticles; Lipoproteins
PubMed: 37270975
DOI: 10.1016/j.saa.2023.122954 -
Spectrochimica Acta. Part A, Molecular... Aug 2023Phosmet is a phthalimide derived broad spectrum organophosphate pesticide which is vastly used across the globe to protect several ornamental or horticulture crops. The...
Phosmet is a phthalimide derived broad spectrum organophosphate pesticide which is vastly used across the globe to protect several ornamental or horticulture crops. The toxicity of phosmet is of utmost concern because of its direct effect on the nervous system of the victim after exposure. The mechanism of phosmet toxicity was explored by the interaction with the model blood protein which is hemoglobin. Bovine Hemoglobin (BHb) is a major protein of red blood cells (RBCs) that plays an important role in the exchange of gases for respiration and ensures adequate oxygen supply to tissues for oxygenation. In the current study, the interaction of BHb with phosmet was revealed using various spectroscopic techniques. Circular dichroism (CD) and Fourier transform infrared spectroscopy (FTIR) studies of BHb in the presence of phosmet showed secondary structural changes in the protein post binding, Fluorescence study shows the involvement of the dynamic quenching predominantly, Van't Hoffs thermodynamic study showed negative enthalpy value and free energy change and negative entropy change that revealed the involvement of hydrogen bonding and van der Waal forces predominantly further revealing spontaneous nature of binding interaction. The shift in Ultraviolet-visible spectra also revealed the nature of the interaction. In-silico study finally deduced the involvement of hydrogen bonding and polar interaction. The study inferred the moderate interaction of BHb with phosmet.
Topics: Phosmet; Molecular Docking Simulation; Protein Binding; Thermodynamics; Hemoglobins; Circular Dichroism; Binding Sites; Spectrometry, Fluorescence; Serum Albumin, Bovine; Spectrophotometry, Ultraviolet
PubMed: 37001261
DOI: 10.1016/j.saa.2023.122630 -
Microscopy Research and Technique Oct 2023Due to the diverse and rich taxa, Asteraceae needs to explore from the untouched area. In this study, the pollen study was intended to assess the taxonomic value for...
Due to the diverse and rich taxa, Asteraceae needs to explore from the untouched area. In this study, the pollen study was intended to assess the taxonomic value for Asteraceous taxa growing on the Sikaram Mountain Pak-Afghan border. Both microscopic techniques (LM and SEM) play a significant role in the identification and classification of herbaceous species of Asteraceae for their taxonomic and systematic implication. Pollen was observed and measured for the 15 species of Asteraceae. For investigated taxa 15 pollen characters with size, shape, polar view, pollen type, aperture orientation, and exine sculpturing in the eurypalynous pollen. Consequently, the pollen grains are usually Tricolporate, triangular to circular in polar view, while, the shape of pollen varies from subulate, oblate, and prolate along with prolate to spheroidal whereas, sculpturing also varies from Scabrate to micro reticulate, echino-perforate, Scabrate to echinate, echinate to granulate and echinate were observed. Similarly, among the quantitative data minimum values of polar and equatorial were 15.8 ± 0.74 μm in Filago pyramidata and 17.85 ± 0.39 μm in Heteropappus altaicus was measured respectively, while; the length of the spine with the least value of 2.45 ± 0.31 μm in Hertia intermedia and highest with 7.55 ± 0.31 μm was observed in Cirsium wallichii. The Exine thickness is a minimum of 1.70 ± 0.35 μm in Launaea nudicaulis and a maximum of 5.65 ± 3.59 μm in Cirssium vulgare. In addition, the highest pollen fertility (87%) in Centaurea iberica while the highest pollen sterility (32%) was recorded in Cirsium verutum. Furthermore, clustering via UPGMA, PCA, and PCoA analysis was performed for the separation of closely related taxa. It is concluded from this research work that palynological study has a crucial role in taxonomic, pure, and applied sciences. This study can be further authenticated and improved by a Phylogenetic study based on chloroplast DNA analysis & whole genome sequencing. RESEARCH HIGHLIGHTS: Pollen ultrastructure among 15 Asteraceous taxa. Micromorphological attributes measured via LM and SEM. Exine sculpture elements patterns provide accurate identification. Taxonomic keys were developed for its systematics implications.
Topics: Microscopy, Electron, Scanning; Asteraceae; Phosmet; Phylogeny; Plants
PubMed: 36883756
DOI: 10.1002/jemt.24311