Eco-friendly chitosan microspheres as a novel one-step sorbent for the rapid purification and determination of pesticides and veterinary drug multi-residues in aquatic products with HPLC-MS/MS.

A modified QuEChERS method was developed to determine multi-class pesticide and veterinary residues in aquatic products. Chitosan microspheres were conveniently synthesized and utilized as the cleanup adsorbent in the QuEChERS procedure, showcasing rapid filtration one-step pretreatment ability for the determination of drug multi-residues in aquatic products. Compared to conventional synthetic sorbents, chitosan microspheres not only have good purification performance, but also have renewable and degradable properties. This novel sorbent worked well in the simultaneous determination of 95 pesticides and veterinary drug residues in aquatic products after being combined with an improved one-step vortex oscillating cleanup method. We achieved recoveries ranging from 64.0% to 115.9% for target drugs in shrimp and fish matrix. The limits of detection and quantification were 0.5-1.0 and 1.0-2.0 µg kg-1, respectively. Notably, hydrocortisone was detected with considerable frequency and concentration in the tested samples, underscoring the necessity for stringent monitoring of this compound in aquatic products.

Application of Difluoromethyl Isosteres in the Design of Pesticide Active Molecules.

Difluoromethyl (CF2H) groups have been found in many listed pesticides due to their unique physical and chemical properties and outstanding biological activity. In pesticide molecules, compared with the drastic changes brought by trifluoromethyl, difluoromethyl usually moderately regulates the metabolic stability, lipophilicity, bioavailability, and binding affinity of compounds. Therefore, difluoromethylation has become an effective means to modify the biological activity of pesticide molecules. This paper reviews the representative literatures and patents containing difluoromethyl groups in the past 10 years, and introduces the research progress. The aim is to provide an effective reference value for the study of difluoromethyl in pesticides.

Molecular interaction mechanisms on (-)-epigallocatechin-3-gallate improving activities of inhibited acetylcholinesterase by selected organophosphorus pesticides in vitro & vivo.

(-)-Epigallocatechin-3-gallate (EGCG) is reported to have benefits for the treatment of Alzheimer's disease by binding with acetylcholinesterase (AChE) to enhance the cholinergic neurotransmission. Organophosphorus pesticides (OPs) inhibited AChE and damaged the nervous system. This study investigated the combined effects of EGCG and OPs on AChE activities in vitro & vivo. The results indicated that EGCG significantly reversed the inhibition of AChE caused by OPs. In vitro, EGCG reactived AChE in three group tubes incubated for 110 min, and in vivo, it increased the relative activities of AChE from less than 20% to over 70% in brain and vertebral of zebrafish during the exposure of 34 h. The study also proposed the molecular interaction mechanisms through the reactive kinetics and computational analyses of density functional theory, molecular docking, and dynamic modeling. These analyses suggested that EGCG occupied the key residues, preventing OPs from binding to the catalytic center of AChE, and interfering with the initial affinity of OPs to the central active site. Hydrogen bonding, conjugation, and steric interactions were identified as playing important roles in the molecular interactions. The work suggests that EGCG antagonized the inhibitions of OPs on AChE activities and potentially offered the neuroprotection against the induced damage.

Redox-Responsive Nanopesticides Based on Natural Polymers for Environmentally Safe Delivery of Pesticides with Enhanced Foliar Dispersion and Washout Resistance.

Based on the modified cross-linking of the degradable natural polymers chitosan oligosaccharides (COS) and gelatin (GEL) via introduction of a functional bridge 3,3'-dithiodipropionic acid, this study constructed an environmentally responsive dinotefuran (DNF) delivery system (DNF@COS-SS-GEL). The introduction of the disulfide bond (-S-S-) endowed DNF@COS-SS-GEL with redox-responsive properties, allowing for the rapid release of pesticides when stimulated by glutathione (GSH) in the simulated insect. Compared with commercial DNF suspension concentrate (DNF-SC), DNF@COS-SS-GEL showed superior wet spreading and retention performance on cabbage leaves with a reduced contact angle (57°) at 180 s and 4-fold increased retention capacity after rainfall washout. Nanoencapsulation effectively improved the UV-photostability with only a 31.4% decomposition rate of DNF@COS-SS-GEL at 96 h. The small scale and large specific surface area resulted in excellent uptake and transportation properties in plants as well as higher bioactivity against Plutella xylostella larvae. This study will help promote sustainable agricultural development by reducing environmental pollution through improved pesticide utilization.

Compositional Optimization for Miticidal Activity, Ecotoxicity, and Phytotoxicity of Rosmarinus officinalis Essential Oils as Biorational Pesticides.

Recognizing the challenges in using botanicals as sustainable pest control agents due to compositional variation, this study addresses the limitations of traditional component-based approaches such as Hewlett and Plackett or Wadley's models. Based on the assumption of noninteractivity among constituents, these models often fail to predict outcomes accurately due to dynamic intermolecular interactions. We introduce a whole mixture-based approach, employing a combination of experimental design and polynomial modeling. This technique accurately predicts miticidal activity on Tetranychus urticae, ecotoxicity on Daphnia magna, and phytotoxic activities on Phaseolus vulgaris of Rosemarinus officinalis essential oils with varying composition. The RMSE values from the polynomial model are 66.9 and 5.0 for miticidal activity and ecotoxicity, respectively, while they are much higher in component-based models, up to 1097.7 and 41.3, respectively. Additionally, we utilize multiobjective optimization algorithms to identify the optimal supplementary blending of oils and compounds. This strategy aims to maximize miticidal effectiveness while minimizing ecotoxicity and phytotoxicity. Our approach for predicting multicomponent mixture effects is likely to bridge the knowledge gap between research and commercialization.

Development of a Novel SPME Coating for Efficient Extraction of Organochlorine Pesticides in Liquid Dairy Products.

A sensitive and accurate analysis of organochlorine pesticide (OCP) residues in dairy products poses a significant challenge. Herein, a novel covalent organic polymer, Azo-COP-1, was synthesized for the enhanced extraction of OCPs in dairy products. The solid phase microextraction fiber coated with Azo-COP-1 demonstrated excellent extraction performance for the OCPs via hydrogen bonding, halogen bonding, π-π stacking, and electrostatic interactions. Coupled with gas chromatography-electron capture detection, we developed a facile and reliable method for detecting OCPs in six types of dairy products with low limits of detection (2.0-400 pg g-1) and high method recoveries (82.6-113%). Azo-COP-1 coatings exhibited good stability and durability. The results verified the feasibility of using Azo-COP-1-based SPME to extract OCP residues in dairy product samples, highlighting its potential for routine monitoring of pesticide residues and food safety assessments.

Bioaugmentation: a strategy for enhanced degradation of pesticides in biobed.

Biopurification system (BPS) or biobeds are low-cost system for decontamination of on-farm generated pesticide waste. A biobed contains a mixture of soil, lignocellulosic biomass and organic matter source (compost/peat) and works on the principal of retention of pesticide in high organic matter matrix and its subsequent degradation by microbes. Bioaugmentation, a green technology, is defined as the improvement of the degradative capacity of biobeds by augmenting specific microorganisms. During last 20 years, several studies have evaluated pesticide degradation in biobeds augmented with bacterial and fungal species and prominent microorganism include genus Pseudomonas, Sphingomonas, Arthrobacter, Phanerochaete, Stereum, Delftia, Trametes, Streptomyces etc. Degradation of pesticides belonging to major classes have been studied in the bioaugmented biobeds. Studies suggested that some pesticides were degraded faster in the bioaugmented biobeds subject to survival and proliferation of degrading microbe. However, no effect of bioaugmentation was observed on degradation of some pesticides and no clear reason for the same was evident. Bioaugmentation with pesticide degrading microorganisms/consortium in combination with rhizosphere-assisted biodegradation could be an optimal strategy for accelerating the degradation of pesticides in biobeds.

Sensitive Coatings Based on Molecular-Imprinted Polymers for Triazine Pesticides' Detection.

Triazine pesticide (atrazine and its derivatives) detection sensors have been developed to thoroughly check for the presence of these chemicals and ultimately prevent their exposure to humans. Sensitive coatings were designed by utilizing molecular imprinting technology, which aims to create artificial receptors for the detection of chlorotriazine pesticides with gravimetric transducers. Initially, imprinted polymers were developed, using acrylate and methacrylate monomers containing hydrophilic and hydrophobic side chains, specifically for atrazine, which shares a basic heterocyclic triazine structure with its structural analogs. By adjusting the ratio of the acid to the cross-linker and introducing acrylate ester as a copolymer, optimal non-covalent interactions were achieved with the hydrophobic core of triazine molecules and their amino groups. A maximum sensor response of 546 Hz (frequency shift/layer height equal to 87.36) was observed for a sensitive coating composed of 46% methacrylic acid and 54% ethylene glycol dimethacrylate, with a demonstrated layer height of 250 nm (6.25 kHz). The molecularly imprinted copolymer demonstrated fully reversible sensor responses, not only for atrazine but also for its metabolites, like des-ethyl atrazine, and structural analogs, such as propazine and terbuthylazine. The efficiency of modified molecularly imprinted polymers for targeted analytes was tested by combining them with a universally applicable quartz crystal microbalance transducer. The stable selectivity pattern of the developed sensor provides an excellent basis for a pattern recognition procedure.

Fabrication of thermo-responsive microcapsule pesticide delivery system from maleic anhydride-functionalized cellulose nanocrystals-stabilized pickering emulsion template.

The overuse of pesticides has shown their malpractices. Novel and sustainable formulations have consequently attracted abundant attention but still appear to have drawbacks. Here, we use a maleic anhydride-functionalized cellulose nanocrystals-stabilized Pickering emulsions template to prepare thermo-responsive microcapsules for a pesticide delivery system via radical polymerization with N-isopropyl acrylamide. The microcapsules (MACNCs-g-NIPAM) are characterized by the microscope, SEM, FTIR, XRD, TG-DTG, and DSC techniques. Imidacloprid (IMI) is loaded on MACNCs-g-NIPAM to form smart release systems (IMI@MACNCs-g-NIPAM) with high encapsulation efficiency (~88.49%) and loading capability (~55.02%). The IMI@MACNCs-g-NIPAM present a significant thermo-responsiveness by comparing the release ratios at 35°C and 25°C (76.22% vs 50.78%). It also exhibits advantages in spreadability, retention and flush resistance on the leaf surface compared with the commercial IMI water-dispersible granules (CG). IMI@MACNCs-g-NIPAM also manifest a significant advantage over CG (11.12 mg/L vs 38.90 mg/L for LC50) regarding activity tests of targeted organisms. In addition, IMI@MACNCs-g-NIPAM has shown excellent biocompatibility and low toxicity. All the benefits mentioned above prove the excellent potential of IMI@MACNCs-g-NIPAM as a smart pesticide formulation.

Combining QSAR and SSD to predict aquatic toxicity and species sensitivity of pyrethroid and organophosphate pesticides.

The widespread use of pyrethroid and organophosphate pesticides necessitates accurate toxicity predictions for regulatory compliance. In this study QSAR and SSD models for six pyrethroid and four organophosphate compounds using QSAR Toolbox and SSD Toolbox have been developed. The QSAR models, described by the formula 48 h-EC50 or 96 h-LC50 = x + y * log Kow, were validated for predicting 48 h-EC50 values for acute Daphnia toxicity and 96 h-LC50 values for acute fish toxicity, meeting criteria of n ≥10, r2 ≥0.7, and Q2 >0.5. Predicted 48 h-EC50 values for pyrethroids ranged from 3.95 × 10-5 mg/L (permethrin) to 8.21 × 10-3 mg/L (fenpropathrin), and 96 h-LC50 values from 3.89 × 10-5 mg/L (permethrin) to 1.68 × 10-2 mg/L (metofluthrin). For organophosphates, 48 h-EC50 values ranged from 2.00 × 10-5 mg/L (carbophenothion) to 3.76 × 10-2 mg/L (crufomate) and 96 h-LC50 values from 3.81 × 10-3 mg/L (carbophenothion) to 12.3 mg/L (crufomate). These values show a good agreement with experimental data, though some, like Carbophenothion, overestimated toxicity. HC05 values, indicating hazardous concentrations for 5% of species, range from 0.029 to 0.061 µg/L for pyrethroids and 0.030 to 0.072 µg/L for organophosphates. These values aid in establishing environmental quality standards (EQS). Compared to existing EQS, HC05 values for pyrethroids were less conservative, while those for organophosphates were comparable.

Advancing rational pesticide development against Drosophila suzukii: bioinformatics tools and applications-a systematic review.

CONTEXT: Drosophila suzukii (Matsumura, 1931) is a widespread agricultural pest responsible for significant damage to various soft-skinned fruit hosts. The revolutionary potential of bioinformatics in agriculture emerges from its ability to provide extensive information on pests, fungi, chemical resistance, implications of non-target species, and other critical aspects. This wealth of information allows researchers to engage in projects and applied research in diverse agricultural domains that face these challenges. In this context, bioinformatics tools play a fundamental role. The negative impact of pests on crops, resulting in substantial economic losses, has highlighted the importance of in silico methods. METHODS: To achieve this, we conducted a systematic search in scientific databases using as keywords "Drosophila suzukii," "biopesticides," "simulations computational," and "in-silico." After applying the filters of relevance and publication date, we organized the articles and prioritized those that directly addressed that matched the keywords and the use of bioinformatics tools. Additionally, we included studies focusing on in silico assays of biopesticides, such as molecular docking. Our review aimed to present a collection of recent literature on biopesticides against Drosophila suzukii, emphasizing bioinformatics methods. Through this work, we strive to contribute to the literature of new perspectives on the development and efficiency of biopesticides, along with to advance research that may improve pest control strategies. RESULTS: In the results of the systematic review, we found 2734 articles related to the selected keywords. Six of these articles directly address Drosophila suzukii and the use of bioinformatics tools in the search for alternatives in pest control. In the selected studies, we observed that two articles tend to focus on phylogenetic approaches, searching for gene sequences, amino acids, and constructing phylogenetic trees. The other three articles used molecular modeling and docking of receptors such as GABA and TRP with plant-derived and synthetic compounds to study intermolecular interactions. However, we identified gaps in these studies that could lead to further research in the biorational development of biopesticides using bioinformatics tools.

Encapsulated Thuja plicata essential oil into biopolymer matrix as a potential pesticide against Phytophthora root pathogens.

A new formulation that gradually released encapsulated Thuja plicata essential oil (TPEO) as an active component from a biopolymer matrix within a given period was obtained. Antimicrobial activity was determined in in-vitro tests where pure TPEO successfully inhibited the development of different Phytophthora species. The TPEO essential oil was encapsulated into the biopolymer matrix and an oil-in-water emulsion was formed. FTIR spectra analysis confirmed the formation of electrostatic interaction between these polymers, and hydrogen interactions between active components of TPEO and polymer chains. The stability of the emulsions was confirmed by zeta potential measurements, with a value of about 30 mV, even after 14 days of aging. UV-Vis spectra analysis revealed that >60 % of TPEO remained in the emulsion after 14 days of exposure to ambient conditions, whereas pure TPEO evaporated faster, and around 20 % remained after 6 days. Encapsulated TPEO almost completely inhibited the growth of Phytophthora species during the ten-day day's exposition being statistically significantly improved compared to fungicide treatment. It was demonstrated that the emulsion exhibited a prolonged antimicrobial effect and successfully suppressed the growth of Phytophthora species, and can be considered as a means of protection in forests and crops.

Temporal Dynamics of Copper-Based Nanopesticide Transfer and Subsequent Modulation of the Interplay Between Host and Microbiota Across Trophic Levels.

During agricultural production, significant quantities of copper-based nanopesticides (CBNPs) may be released into terrestrial ecosystems through foliar spraying, thereby posing a potential risk of biological transmission via food chains. Consequently, we investigated the trophic transfer of two commonly available commercial CBNPs, Reap2000 (RP) and HolyCu (HC), in a plant-caterpillar terrestrial food chain and evaluated impacts on host microbiota. Upon foliar exposure (with 4 rounds of spraying, totaling 6.0 mg CBNPs per plant), leaf Cu accumulation levels were 726 ± 180 and 571 ± 121 mg kg-1 for RP and HC, respectively. HC exhibited less penetration through the cuticle compared to RP (RP: 55.5%; HC: 32.8%), possibly due to size exclusion limitations. While caterpillars accumulated higher amounts of RP, HC exhibited a slightly higher trophic transfer factor (TTF; RP: 0.69 ± 0.20; HC: 0.74 ± 0.17, p > 0.05) and was more likely to be transferred through the food chain. The application of RP promoted the dispersal of phyllosphere microbes and perturbed the original host intestinal microbiota, whereas the HC group was largely host-modulated (control: 65%; RP: 94%; HC: 34%). Integrating multiomics analyses and modeling approaches, we elucidated two pathways by which plants exert bottom-up control over caterpillar health. Beyond the direct transmission of phyllosphere microbes, the leaf microbiome recruited upon exposure to CBNPs further influenced the ingestion behavior and intestinal microbiota of caterpillars via altered leaf metabolites. Elevated Proteobacteria abundance benefited caterpillar growth with RP, while the reduction of Proteobacteria with HC increased the risk of lipid metabolism issues and gut disease. The recruited Bacteroidota in the RP phyllosphere proliferated more extensively into the caterpillar gut to enhance stress resistance. Overall, the gut microbes reshaped in RP caterpillars exerted a strong regulatory effect on host health. These findings expand our understanding of the dynamic transmission of host-microbiota interactions with foliar CBNPs exposure, and provide critical insight necessary to ensure the safety and sustainability of nanoenabled agricultural strategies.

Hexafluoroisopropanol-based supramolecular solvent for liquid phase microextraction of pesticides in milk.

Residues of pesticides in milk may pose a threat to human health. This study aimed to develop a liquid-phase microextraction (LPME) method using hexafluoroisopropanol (HFIP)-based supramolecular solvent (SUPRAS) for the simultaneous extraction and purification of four pesticides (boscalid, novaluron, cypermethrin and bifenthrin) in milk. Pesticides were extracted using SUPRAS prepared with nonanol and HFIP, and the extraction efficiency was analyzed. Results showed satisfactory recoveries ranging from 80.8%-111.0%, with relative standard deviations (RSDs) of <6.4%. Additionally, satisfactory linearities were observed, with correlation coefficients >0.9952. The limits of quantification (LOQs) were in the range of 1.8 µg·L-1-14.0 µg·L-1. The established method demonstrated high extraction efficiency with a short operation time (15 mins) and low solvent consumption (2.7 mL). The HFIP-based SUPRAS LPME method offers a convenient and efficient approach for the extraction of pesticides from milk, presenting a promising alternative to conventional techniques.

Cellulase-responsive hydroxypropyl cellulose-anchored hollow mesoporous silica carriers for pesticide delivery.

In this study, a cellulase-responsive controlled-release formulation (FPR-HMS-HPC) was developed by grafting hydroxypropyl cellulose (HPC) onto fipronil (FPR) loaded hollow mesoporous silica (HMS) nanoparticles via ester linkage. The FPR-HMS-HPC formulation was characterized using scanning and transmission electron microscopies, Fourier transform infrared spectroscopy, and thermogravimetric analysis. The results indicated that FPR-HMS-HPC exhibited a high loading capacity of 10.0 % (w/w) and demonstrated favorable responsiveness to cellulase enzyme. Moreover, its insecticidal efficacy against Reticulitermes flaviceps surpassed that of an equivalent dose of FPR. Toxicology studies showed that the mortality and hatching rates of zebrafish exposed to FPR-HMS-HPC nanoparticles were reduced by >6.5 and 8.0 times, respectively. Thus, HPC-anchored HMS nanoparticles as insecticide delivery systems present a sustainable method for pest control significantly reducing harm to non-target organisms and the environment.

Reduced graphene oxide decorated NiCo2(OH)6 nanoflowers for vortexed assisted dispersive µ-solid-phase extraction of organophosphorus pesticides in baby food cereal, rice and wheat flour.

Food safety is an important issue to protect humane health and improve the life quality. Hence, analysis of the possible contaminants in food samples is essential. A rapid and efficient vortexed-assisted dispersive µ-solid-phase extraction coupled with gas chromatography-mass spectrometry was proposed for simultaneous separation/preconcentration and determination of five commonly used organophosphorus pesticides. Reduced graphene oxide decorated NiCo2(OH)6 nanoflowers as a novel nanostructure was synthetized and introduced for separation of the target pesticides from the wheat flour, rice flour, and baby food cereal samples. The characterization of the nanoflowers was accomplished by SEM-EDX, XRD, and FT-IR techniques. The main factors including pH, the amount of nanoflower, the volume of sample solution, salt concentration (ionic strength), desorption conditions (i.e. desorption solvent type and volume, and desorption time) on the pesticides extraction efficiencies were inquired using matrixed match method. Applying the optimum conditions, the linearity of 0.100-500.000 µg kg-1, LODs and LOQs in the range of 0.03-0.04 µg kg-1 and 0.1 µg kg-1 for the studied food samples were obtained. The repeatability (intra-day precision (n = 5)) of ≤ 2.0 % and reproducibility (inter-day precision, days = 5, n = 3) of ≤3.1 % and were appraise at three concentration levels (10, 50 and 100 µg kg-1 of each analyte). High relative recoveries of 90.0-99.3 % ascertained high potential of the presented method for complex matrix analysis.

Fabrication and characterization of biodegradable hydrogel beads of guar gum for the removal of chlorpyrifos pesticide from water.

A new guar gum hydrogel beads were fabricated by dropping method from an aqueous solution of guar gum (GG) using ammonium persulphate and polyethylene glycol as initiator and crosslinker respectively, for the adsorption of chlorpyrifos (CP) from water. The semi-crystalline nature of the synthesized beads was confirmed by FESEM analysis. The TGA studies implied that the beads were thermally stable up to 600 °C. The maximum swelling ratio of 1400 gg-1 was attained at pH 9.2 and 80 min. The evidence of a strong absorption band was found in FTIR spectrum at 584 cm-1 due to -P=S of the adsorbed pesticide CP. The maximum adsorption of CP was found to be 220.97 mgg-1. The adsorption followed pseudo second-order kinetics and Langmuir adsorption isotherm with regression coefficients 0.9998 and 0.9938 which followed the chemisorption process. It is due to the hydrolysis of CP at pH 9.2 to yield 3,5,6-trichloropyridinol which in turn reacts with the carboxylic group present in GG giving -N-C=O linkage. A -ΔG indicates that the process is spontaneous and involves chemisorption which is thermodynamically and kinetically favorable and a -ΔH value (-10.37 kJ/mol) suggests that the adsorption is exothermic.

Biodegradation of chemical contamination by lactic acid bacteria: A biological tool for food safety.

Chemical pollutants such as mycotoxins and pesticides exert harmful effects on human health such as inflammation, oxidative stress, and cancer. Several strategies were applied for food decontamination, including physicochemical and biological strategies. The present review comprehensively discussed the recent efforts related to the biodegradation of eight food chemical contaminants, including mycotoxins, acrylamide, biogenic amines, N-nitrosamines, polycyclic aromatic hydrocarbons, bisphenol A, pesticides, and heavy metals by lactic acid bacteria (LAB). Biological detoxification by LAB such as Lactobacillus is a promising approach to remove the risks related to the presence of chemical and environmental pollutants in foodstuffs. It is a safe, efficient, environmentally friendly, and low-cost strategy to remove hazardous compounds. LAB can directly decrease these chemical pollutants by degradation or adsorption. Also, it can indirectly reduce the content of these pollutants by reducing their precursors. Hence, LAB can contribute to reducing chemical pollutants in contaminated foods and enhance food safety.

The Role of Mass Spectrometry in Protecting Public Health and the Environment from Synthetic Chemicals.

Mass spectrometry (MS) has dramatically transformed environmental protection by facilitating the precise quantification and identification of pollutants. This review charts the evolution of environmental chemistry, intertwining it with advancements in analytical chemistry and MS technologies. It specifically focuses on the role of MS in studying persistent organic pollutants like organochlorine pesticides, polychlorinated biphenyls (PCBs), brominated fire retardants (BFRs), and perfluoroalkyl and polyfluoroalkyl substances (PFAS), marking significant milestones and their implications. Notably, the adoption of gas chromatography with MS in the 1970s and liquid chromatography with MS in the late 1990s profoundly expanded scientists' ability to detect complex pollutant mixtures. Over the past 50 years, the proliferation of potential pollutants has surged, necessitating more sophisticated analysis techniques, such as high-resolution mass spectrometry-nontargeted analysis (HRMS-NTA) and suspect screening. While HRMS promises to enhance the characterization of new environmental pollutants, a significant shift in chemical management strategies remains imperative. Despite technological advances, MS alone is insufficient to mitigate the risks from the continuous emergence of novel chemicals, with many potentially already present in the environment and bioaccumulating in humans.

Graphene Oxide-Based Antifungal Pesticide Delivery System for Tobacco Fungal Disease (Tobacco Target Spot) Control.

In recent years, nanocarrier-based pesticide delivery systems have provided new possibilities for the efficient utilization of pesticides. In this research, we developed a hydroxypropyl-ß-cyclodextrin-modified graphene oxide (GO-HP-ß-CD) nanocarrier for pyraclostrobin (Pyr) delivery and studied its application for tobacco target spot disease control. GO-HP-ß-CD has excellent pesticide-loading performance for Pyr (adsorption capacity of 1562.5 mg/g) and good water dispersibility and stability. Besides, GO-HP-ß-CD shows pH-responsive release performance. In addition, GO-HP-ß-CD also has better leaf affinity than Pyr, and it can effectively adhere to the leaf surface after simulated washing. The results of antifungal experiments indicate that GO-HP-ß-CD-Pyr has a good preventive effect on tobacco target spot disease, and its EC50 value is 0.384 mg/L, which is lower than Pyr. Specifically, this nanopesticide formulation does not contain toxic organic solvent or additive, so it has good environmental friendliness. Therefore, we believe that the GO-HP-ß-CD-Pyr nanopesticide has brilliant potential in the prevention and control of tobacco diseases.