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Analytica Chimica Acta May 2022In this work, we reported the first use of a novel fluorescent probe for phoxim detection based on yellowish-green emissive carbon quantum dots (CQDs). By facile one-pot...
In this work, we reported the first use of a novel fluorescent probe for phoxim detection based on yellowish-green emissive carbon quantum dots (CQDs). By facile one-pot hydrothermal treatment of citric acid and p-phenylenediamine, the CQDs with yellowish-green luminescence were synthesized. The sensing mechanism is based on the quenching effect of phoxim on the fluorescence emission of CQDs by inner filter effect (IFE). The CQDs showed a good sensitivity and selectivity to phoxim detection and dual good linear relationships were provided in the concentration ranges of 1-10 μM and 10-98 μM, associated with the limit of detection of 0.09 μM. The proposed assay has been allowed to detect phoxim in real samples with satisfying recoveries ranging from 93 to 105.9%. Furthermore, due to the low cytotoxicity and excellent biocompatibility, the as-prepared CQDs was successfully used for cell imaging, demonstrating the considerable potential applications of such CQDs in biological field.
Topics: Carbon; Fluorescent Dyes; Organothiophosphorus Compounds; Quantum Dots
PubMed: 35473876
DOI: 10.1016/j.aca.2021.338685 -
Journal of Agricultural and Food... May 2024Aryl hydrocarbon receptor (AhR) and aryl hydrocarbon receptor nuclear translocator (ARNT) mediate the responses of adaptive metabolism to various xenobiotics. Here, we...
Aryl hydrocarbon receptor (AhR) and aryl hydrocarbon receptor nuclear translocator (ARNT) mediate the responses of adaptive metabolism to various xenobiotics. Here, we found that and are highly expressed in the midgut of larvae. The expression of and was significantly increased after exposure to imidacloprid and phoxim. The knockdown of and significantly decreased the expression of and as well as P450 enzyme activity and caused a significant increase in the sensitivity of larvae to imidacloprid and phoxim. Exposure to β-naphthoflavone (BNF) significantly increased the expression of , , and as well as P450 activity and decreased larval sensitivity to imidacloprid and phoxim. Furthermore, and were significantly induced by imidacloprid and phoxim, and the silencing of these two genes significantly reduced larval tolerance to imidacloprid and phoxim. Taken together, the BoAhRBoARNT pathway plays key roles in larval tolerance to imidacloprid and phoxim by regulating the expression of and .
Topics: Animals; Insecticides; Larva; Nitro Compounds; Neonicotinoids; Insect Proteins; Receptors, Aryl Hydrocarbon; Diptera; Aryl Hydrocarbon Receptor Nuclear Translocator; Cytochrome P-450 Enzyme System; Inactivation, Metabolic; Transcription Factors
PubMed: 38712504
DOI: 10.1021/acs.jafc.4c00358 -
Food Chemistry Jul 2022A ratiometric electrochemical immunosensor, based on DNA tetrahedron nanostructure (DTNS), is introduced for vegetable phoxim determination. DTNS spontaneously adheres...
Ratiometric immunosensor with DNA tetrahedron nanostructure as high-performance carrier of reference signal and its applications in selective phoxim determination for vegetables.
A ratiometric electrochemical immunosensor, based on DNA tetrahedron nanostructure (DTNS), is introduced for vegetable phoxim determination. DTNS spontaneously adheres onto gold-nanoparticle-modified electrode and forms stable three-dimensional structure, providing plenty of binding sites to the built-in reference, methylene blue (MB). Monoclonal antibody (m-Ab) is vertically linked onto DTNS vertex, selectively responses antigenic phoxim, and promotes the target signal of I. Thus, a ratiometric indicator, I/I, is sensibly established with the target signal (I) and the reference signal (I). Modifications, mechanisms and advances of the proposed method are subsequently examined with morphological methods and electrochemical experiments. This method brings considerable advances in analytical behaviors. The ratiometric signal presents better performance than solo system in repeatability and long-time stability. As-fabricated sensor presents wide dynamic range as 0.1∼30 μg/L, and limit of detection is well defined as 0.003 μg/L (S/N = 3). Finally, this method is verified with real-vegetable-sample analysis, certified HPLC and recovery test.
Topics: Biosensing Techniques; DNA; Electrochemical Techniques; Gold; Immunoassay; Limit of Detection; Methylene Blue; Nanostructures; Organothiophosphorus Compounds; Vegetables
PubMed: 35182867
DOI: 10.1016/j.foodchem.2022.132445 -
Food Chemistry Jun 2022Organophosphorus pesticides will not only affect human health, but will also have serious impacts on the ecological environment. A simple, economical, safe, efficient,...
Organophosphorus pesticides will not only affect human health, but will also have serious impacts on the ecological environment. A simple, economical, safe, efficient, green and pollution-free and highly sensitive method was successfully established to analyze organophosphorus pesticides in different coarse cereals' samples. Under the optimal experimental conditions, the method was linear, the correlation coefficient are higher than 0.9639. The detection limits of trichlorfon, chlorpyrifos, phoxim, fenthion, and diazinon were 2.6, 2.0, 4.3, 2.0, and 2.8 μg/kg. The recoveries ranged from 92.8 to 105.2%, the relative standard deviation is less than 5.2%. The results obtained show that the proposed method has the advantages of economy, safety, green and pollution-free, high recovery efficiency, simple use of the instrument, simple operation, and can be used with many subsequent instruments.
Topics: Chlorpyrifos; Edible Grain; Humans; Ionic Liquids; Organophosphorus Compounds; Pesticides
PubMed: 35065493
DOI: 10.1016/j.foodchem.2022.132161 -
Journal of Agricultural and Food... Dec 2019Organophosphorus insecticides (OPs) have been widely used to control agricultural pests, which has raised concerns about OP residues in crops and the environment. In...
Organophosphorus insecticides (OPs) have been widely used to control agricultural pests, which has raised concerns about OP residues in crops and the environment. In this study, we investigated the degradation kinetics and pathways of 8 OPs by X1 and identified the enzyme via gene cloning and in vitro assays. The degradation half-life of methyl parathion, triazophos, and phoxim was only 5, 9, and 43 min, respectively. It was 46 fold faster than that of triazophos by sp. TAP-1, a well-studied triazophos-degrader. Strain X1 completely degraded not only chlorpyrifos, methyl parathion, parathion, fenitrothion, triazophos, and phoxim at 50 mg/L within 48 h but also the phenolic metabolites. This was the fastest degradation of OPs by bacterial whole cells reported thus far. The OPs were first hydrolyzed by an OP hydrolase encoded by the gene in strain X1, followed by further degradation of the metabolites. The crude enzyme maintained a full activity.
Topics: Bacillus; Biodegradation, Environmental; Chlorpyrifos; Cupriavidus; Insecticides; Kinetics; Organothiophosphates; Triazoles
PubMed: 31738544
DOI: 10.1021/acs.jafc.9b06157 -
Pesticide Biochemistry and Physiology Nov 2021Meteorus pulchricornis (Wesmael) (Hymenoptera: Braconidae) is a predominant endoparasitoid of lepidopteran pests in mulberry fields. Extensive application of...
Meteorus pulchricornis (Wesmael) (Hymenoptera: Braconidae) is a predominant endoparasitoid of lepidopteran pests in mulberry fields. Extensive application of insecticides puts natural enemies under threat. UDP-glycosyltransferases (UGTs), as important detoxification enzymes, potentially contribute to the detoxification of pesticides in insects. To investigate the roles of UGTs in the process of tolerance towards commonly used insecticides in M. pulchricornis, ten UGT genes were identified from the transcriptome database of M. pulchricornis. Seven UGT genes contained full-length ORFs and shared 47.12-78.28% identity with other homologous hymenopteran insects. qRT-PCR validation revealed that UGT genes can be induced by treatment of sublethal doses of phoxim, cypermethrin and chlorfenapyr, respectively, and these upregulations were depending on the time post insecticide treatments. To further explore the functions of UGT genes, three MpulUGT genes were singly knocked down, which resulted in the decline of UGT expression and significantly increased mortality of parasitoids under sublethal doses of insecticides exposure. This study revealed that UGTs in M. pulchricornis contributed to the tolerance towards insecticides and provided basic insight into the insecticide detoxification mechanism in parasitoid wasps.
Topics: Animals; Glycosyltransferases; Insecticides; Uridine Diphosphate; Wasps
PubMed: 34802517
DOI: 10.1016/j.pestbp.2021.104967 -
Pesticide Biochemistry and Physiology Jul 2020Silkworm (Bombyx mori) is an economically important insect. However, the survival of silkworms has been significantly affected by the assault of chemical pesticides on...
Silkworm (Bombyx mori) is an economically important insect. However, the survival of silkworms has been significantly affected by the assault of chemical pesticides on mulberry trees through aerial application and water currents. Phoxim is a broad-spectrum organophosphorus insecticide widely used in China. Currently, very little is known about the non-neuronal effects of sublethal exposure to phoxim. The purpose of this study was to investigate the non-neuronal effects of sublethal phoxim exposure in the silkworm midgut, with a focus on nutrient metabolism. After phoxim treatment, lipase activity in the silkworm was shown to be up-regulated at 24 h before a decreasing trend was seen. Meanwhile, α-amylase activity showed the opposite trend. The expression levels of mitochondrial respiratory chain-related genes were all up-regulated at 24 h before falling continuously. To ensure that the effects of phoxim on nutrient metabolism were not simply a consequence of a decrease in mulberry consumption, the silkworms were treated with a reduced-food diet before the digestive enzyme activities and the transcription levels of mitochondrial respiratory chain-related genes were analyzed. Our results showed that the patterns in the reduced-diet and phoxim-exposed silkworm were markedly different, suggesting the alterations in the phoxim-exposed silkworm cannot readily be explained by nutrient deprivation.
Topics: Animals; Bombyx; China; Feeding Behavior; Insect Proteins; Nutrients; Organothiophosphorus Compounds
PubMed: 32527421
DOI: 10.1016/j.pestbp.2020.104593 -
Ecotoxicology and Environmental Safety Sep 2023UDP-glucuronosyltransferases (UGTs) could transform various exogenous and endogenous compounds, which help detoxification of pesticides in insects. To investigate the...
UDP-glucuronosyltransferases (UGTs) could transform various exogenous and endogenous compounds, which help detoxification of pesticides in insects. To investigate the role of UGTs in the detoxification metabolism of insecticides in Chironomus kiiensis, CkUGT302M1, CkUGT302N1, CkUGT308N1 and CkUGT36J1 genes were identified with 1449-1599 bp encoding 482-532 amino acids. Four UGT genes shared 40.86∼53.36% identity with other homologous insect species, and expressed in all developmental stages, notably in the larval and adult stages. Expression of CkUGTs was higher in the gastric caecum, midgut and head. Moreover, CkUGTs expression and activity were significantly increased in C. kiiensis larvae in exposure to sublethal concentrations of carbaryl, deltamethrin and phoxim, respectively. To further explore the functions of UGT genes, the CkUGT308N1 was effectively silenced in 4th instar C. kiiensis larvae by RNA interference, which resulted in the mortality of dsCkUGT308N1 treated larvae increased by 71.43%, 111.11% and 62.50% under sublethal doses of carbaryl, deltamethrin and phoxim at the 24-h time point, respectively. The study revealed that the CkUGT308N1 gene in C. kiiensis could contribute to the metabolism of pesticides and provide a scientific basis for evaluating the water pollution of pesticides.
Topics: Animals; Chironomidae; Insecticides; Carbaryl; Larva; Uridine Diphosphate
PubMed: 37586199
DOI: 10.1016/j.ecoenv.2023.115353 -
Journal of Hazardous Materials Oct 2020Athetis lepigone is one of the most severe polyphagous pests, and it has developed resistance to different chemical insecticides. Insects primarily rely on the olfactory...
Athetis lepigone is one of the most severe polyphagous pests, and it has developed resistance to different chemical insecticides. Insects primarily rely on the olfactory system to recognize various environmental chemicals, including xenobiotics such as insecticides. Here, we expressed two A. lepigone pheromone-binding proteins (AlepPBP2 and AlepPBP3), and observed they had higher binding affinities to phoxim than other insecticides, with Ki was 3.30 ± 0.38 μM and 3.27 ± 0.10 μM, respectively. Molecular dynamics simulation, binding mode analysis, and computational alanine scanning showed that six residues (Phe15, Phe39, Ile55, Leu65, Ile97, and Phe122) of AlepPBP2 and three residues (Phe12, Ile52, and Ile134) of AlepPBP3 maybe as potential residues that can change protein ability to bind an organophosphorus insecticide phoxim. Then, we used site-directed mutagenesis assay to mutate these residues into alanine, respectively. Subsequently, the binding assays displayed that Phe15, Phe39, and Ile97 of AlepPBP2, Phe12 and Ile134 of AlepPBP3 caused a significant decrease of AlepPBPs binding ability to phoxim, suggesting they should play crucial roles in the AlepPBPs/phoxim interactions. Our findings could further advance in using PBPs as unique targets to design and develop precise and environmentally-friendly pest control agents with high insecticidal potential using a computer-aided drug design (CADD) approach.
Topics: Animals; Carrier Proteins; Insect Proteins; Insecticides; Olfaction Disorders; Pheromones
PubMed: 32388456
DOI: 10.1016/j.jhazmat.2020.122777 -
Archives of Insect Biochemistry and... Oct 2022The nuclear receptor (NRs) gene family functions as ligand-dependent transcription factors in a variety of animals, which participates in a variety of biological...
The nuclear receptor (NRs) gene family functions as ligand-dependent transcription factors in a variety of animals, which participates in a variety of biological processes, such as cell differentiation, metabolic regulation, reproduction, development, insect metamorphosis. In this study, a nuclear receptor HR96 gene in silkworm Bombyx mori (BmHR96) was identified, and the responses of BmHR96 gene to 20-hydroxyecdysone (20E), three insecticides, and two disinfectants were analyzed and its function in phoxim exposure was explored. Quantitative real-time polymerase chain reaction indicated that the expression of BmHR96 mRNA was the highest in ovary of 5th instar Day 3 silkworm larvae and in silk gland of the wandering stage. The expression patterns of BmHR96 gene in ovary, head, testis, and midgut of different stages were different. After injecting 20E into B. mori, the expression of BmHR96 mRNA had no significant difference compared with control. Three insecticides and two disinfectants were used to treat B. mori, respectively, and it was found that they had different influence patterns on the expression level of BmHR96. siRNA of BmHR96 was injected into silkworm larvae and the expression of BmHR96 was decreased significantly after injecting 72 h. After silencing of BmHR96, B. mori was fed with phoxim-treated leaves. The results showed that the mortality of B. mori after silencing of BmHR96 was significantly higher than the control. Our results indicated that HR96 plays an important role in regulating the stress response of phoxim.
Topics: Animals; Bombyx; Disinfectants; Insect Proteins; Insecticides; Larva; Organothiophosphorus Compounds; RNA, Messenger
PubMed: 35470488
DOI: 10.1002/arch.21910