Revisiting pesticide pollution: The case of fluorinated pesticides

High-sensitively fluorescent switch-type sensing for Ag+ and halide anions of 2D Cd-based network constructed with logic gates

Effective detection of the concentration of Ag+ ions in bactericidal fluid is one of the necessary conditions for their effective utilization for sterilization. A novel 2D Cd(II) coordination polymer (CP1), named as [Cd(HDPN)(4,4'-bbpy)]·2H2O, was hydrothermally synthesized using 5-(2',4'-dicarboxylphenyl) nicotic acid (H3DPN) and 4,4'-bis(imidazolyl)biphenyl (4,4'-bbpy). The structure analysis discovered that CP1 possessed a 2D network structure of dinuclear inorganic building blocks. Fluorescence sensing discovered that CP1 could high-sensitively detect Ag+, tetracycline, nitrobenzene and pyrimethanil and the lowest limit of detection (LOD) were 1.44 × 10-8M, 2.15 × 10-8M, 8.09 × 10-8M, and 2.54 × 10-7M, respectively. It is worth noting that the quenching occurs after the addition of Ag+ to the aqueous solution of CP1, and then it gradually recovers when one of the halide anions (X- = Cl-, Br- and I-) is added, forming a unique "on-off-on" fluorescence sensor for Ag+ and constructing a simple logic gate. The fluorescence sensing mechanism of CP1 was investigated using ultraviolet-visible spectroscopy, PXRD, XPS, and DFT methods. The research indicates that CP1 is anticipated to serve as an excellent multifunctional fluorescence sensor, especially as a switch-type sensor for Ag+ and the halide anions.

Rational design, synthesis, and antimicrobial evaluation of novel 1,2,4-trizaole-substituted 1,3,4-oxadiazole derivatives with a dual thioether moiety

In this paper, a series of novel 1,2,4-trizaole-substituted 1,3,4-oxadiazole derivatives with a dual thioether moiety were constructed. The synthetic compounds were characterized by 1H NMR, 13C NMR, HRMS, and single crystal diffraction. The antimicrobial activities of title compounds against fungi (Pyricutaria oryzae Cav., Phomopsis sp., Botryosphaeria dothidea, cucumber Botrytis cinerea, tobacco Botrytis cinerea, blueberry Botrytis cinerea) and bacteria (Xanthomonas oryzae pv. oryzicola, Xoc; Xanthomonas axonopodis pv. citri, Xac) revealed these compounds possessed excellent antibacterial activity through mycelial growth rate method and turbidity method, respectively. Among them, compounds 7a, 7d, 7g, 7k, 7l, and 7n had the antibacterial inhibition rate of 90.68, 97.86, 93.61, 97.70, 97.26, and 92.34%, respectively. The EC50 values of 7a, 7d, 7g, 7k, 7l, and 7n were 58.31, 48.76, 58.50, 40.11, 38.15, and 46.99 μg/mL, separately, superior to that of positive control pesticide thiodiazole copper (104.26 μg/mL). The molecular docking simulation of compound 7l and glutathione s-transferase also confirmed its good activity. The in vivo bioassay toward Xac infected citrus leaves was also performed to evaluate the potential of compounds as efficient antibacterial reagent. Further study of antibacterial mechanism was also carried out, including extracellular polysaccharide production, permeability of bacterial membrane, and scanning electron microscope observations. The excellent antibacterial activities of these compounds provided a strong support for its application for preventing and control plant diseases.

Plant-derived artificial miRNA effectively reduced the proliferation of aphid (Aphidoidea) through spray-induced gene silencing

BACKGROUND

Aphids (Hemiptera: Aphididae) are notorious sap-sucking insects that rampantly threaten agricultural production worldwide. Current management against aphids in the field heavily relies on chemical pesticides, which makes economical and eco-friendly methods urgently needed. Spray-induced gene silencing (SIGS) offers a powerful and precise approach to pest management. However, the high costs and instability of double-stranded RNA (dsRNA) regulators applied for downstream RNA interference (RNAi) still limit this strategy. It remains uncertain if RNAi regulators applied in SIGS could extend to small RNA (sRNA), especially miRNA.

RESULTS

We chose two sRNA sequences, miR-9b and miR-VgR, whose corresponding targets ABCG4 and VgR are both essential for aphid growth and development. The efficacy of these sequences was initially verified by chemically synthetic single-stranded RNA (syn-ssRNA). Through spray treatment, we observed a significantly decreased survival number and increased abnormality rate of green peach aphids fed on the host under laboratory conditions. Based on our previous study, we generated transgenic plants expressing artificial miR-9b (amiR-9b) and miR-VgR (amiR-VgR). Remarkably, plant-derived amiRNA exerted potent and long-lasting inhibitory efficacy with merely one percent concentration of chemical synthetics. Notably, the simultaneous application of amiR-9b and amiR-VgR exhibited superior inhibitory efficacy.

CONCLUSION

We explored the potential use of sRNA-based biopesticide through SIGS while investigating the dosage requirements. To optimize this strategy, the utilization of plant-derived amiRNA was proposed. The results suggested that attributed to stability and durability, deploying amiRNA in pest management is a potential and promising solution for the field application. © 2024 Society of Chemical Industry.

Plant Biostimulant as an Environmentally Friendly Alternative to Modern Agriculture

Ensuring the safety of crop production presents a significant challenge to humanity. Pesticides and fertilizers are commonly used to eliminate external interference and provide nutrients, enabling crops to sustain growth and defense. However, the addition of chemical substances does not meet the environmental standards required for agricultural production. Recently, natural sources such as biostimulants have been found to help plants with growth and defense. The development of biostimulants provides new solutions for agricultural product safety and has become a widely utilized tool in agricultural. The review summarizes the classification of biostimulants, including humic-based biostimulant, protein-based biostimulant, oligosaccharide-based biostimulant, metabolites-based biostimulants, inorganic substance, and microbial inoculant. This review attempts to summarize suitable alternative technology that can address the problems and analyze the current state of biostimulants, summarizes the research mechanisms, and anticipates future technological developments and market trends, which provides comprehensive information for researchers to develop biostimulants.

Defluorination as the key trait to gauge the biodegradability of fluorinated pollutants in environmental microbial communities

Research on microbial defluorination is largely centred on controlled experiments using axenic or well defined microbial inocula. These approaches serve a relevant purpose in the field, offering fundamental biochemical and mechanistic insights on the intricacies of biological defluorination. However, they fail to account for the effective contribution of environmental microbial communities in the recycling of fluoroorganic pollutants, a highly relevant perspective from an environmental risk assessment standpoint, while also missing an important outlook on how community-wide dynamics can leverage the breakdown of C─F bonds in these recalcitrant compounds. With that in mind, this chapter provides experimental and methodological insights on the study of microbial defluorination in wild environmental communities, using this critical catabolic step as the de facto endpoint to evolve, select and cultivate microorganisms with improved defluorination performances.

Assessment of Potential Accumulation of Trifluoroacetate in Terminal Lakes

Trifluoroacetate (TFA) is the anionic form of the shortest perfluorocarboxylic acid (PFCA) and is ubiquitous in the environment at concentrations that are typically much higher than those of other PFCAs. As a stable and nonvolatile anion, it is expected to accumulate in terminal lakes in endorheic basins. This research sampled eight terminal lakes in the Western United States to determine the degree to which TFA is concentrating in these lakes and compare the data to samples collected from three of these lakes 25 years ago. The first observation was that three of the six terminal lakes sampled had higher TFA concentrations than their input streams, while the last two lakes lacked surface water inputs at the sampling time. The TFA concentrations in Mono Lake effectively remained constant over 25 years despite the input stream concentrations increasing 6.5-fold. In contrast, Pyramid Lake concentrations increased approximately the expected amount based on a simplistic analysis of input flows and concentrations. An additional observation was that lakes in basins with agricultural activity appeared to have higher TFA concentrations, which suggests an agricultural input.

Pesticide effect on earthworm lethality via interpretable machine learning

Earthworms are among the most important animals (invertebrates) for soil health. Many chemical substances released into nature for agricultural development, such as pesticides, may have unwanted effects on those organisms. However, it is essential to understand the extent of the impact of chemicals on soil health first and then make the proper decisions for regulatory or commercial purposes. We hypothesize that there is an expressible quantitative structure-activity relationship (QSAR) between the structure of pesticide compounds and the acute toxicity effect of earthworm species Eisenia fetida. The description of this relationship allows for a better assessment of the impact of chemicals on the said earthworm. To describe this relationship, a dataset of chemicals was collected from open-access sources to develop a mathematical model. A novel approach, combining genetic algorithm and Bayesian optimization, was used to select structural features into the model and to optimize model parameters. The final QSAR classification model was created with the Random Forest algorithm and exhibited good prediction Accuracy of 0.78 on training set and 0.80 on test set. The model representation follows FAIR principles and is available on QsarDB.org.

Aquatic toxicity, ecological effects, human exposure pathways and health risk assessment of liquid crystal monomers

Liquid crystal monomers (LCMs), one of the key materials for liquid crystal displays, have been considered as emerging pollutants in recent years. However, the environmental behaviors of LCMs have not yet been well investigated. The toxicity data of 1173 LCMs were calculated by integrated computational simulation methods in this study. It showed that 64.6% LCMs exhibited PBT (persistent, bioaccumulative, and toxic) properties. Based on the results, 1173 LCMs were identified as molecules possessing the highest level of acute toxicity to aquatic organisms. Among which, and a human health risk priority control list about LCMs was generated in this study, among which 435 were classified as requiring priority control LCMs. It was confirmed that LCMs could eventually accumulate in the human body along the aquatic food chain or penetrate the bloodstream through the dermis, thereby causing harm to health by identifying the exposure pathways of LCMs in humans. Additionally, the electronegativity of the side chain group of LCMs is the main factor causing toxicity differences; therefore, the LCMs containing halogens presented significant acute and chronic toxic effects. This study provided a more comprehensive understanding of LCMs for the public and scientific strategies for controlling LCMs.

Fluorine mass balance analysis of PFAS in communal waters at a wastewater plant from Austria

Wastewater treatment plants are a major source of per and polyfluoroalkyl substances (PFAS) in the environment; moreover, long chain PFAS are known to accumulate in sewage sludge. Although publications on PFAS in wastewater are available from around the globe, little information is available from Central Europe. In this study influent, effluent, and sludge from two wastewater treatment plants from Austria were analysed for target PFAS compounds with HPLC MS/MS and extractable organic fluorine (EOF) content with combustion ion chromatography (CIC). The sum of 31 target PFAS increased from 22 to 47 ng L-1 in influent to 140 - 213 ng L-1 in effluent and around 10 ng g-1 in sludge, while EOF were found to be consistent (2.3 - 3.5 µg F L-1) in influent/effluent and 280 ng F g-1 in sludge. Mass balance analysis showed an increase in the identified PFAS compounds in the effluent compared to the influent (from 0.9% - 1.3% to 3.6% - 6.1%), suggesting biotransformation of non-targeted PFAS precursor compounds. In conclusion, wastewater treatment plants transform some PFAS, and wastewater effluent is a source of PFAS contamination in surface water.

The wide presence of fluorinated compounds in common chemical products and the environment: a review

The C-F bonds, due to their many unique features, have been incorporated into numerous compounds in countless products and applications. These fluorinated compounds eventually are disposed of and released into the environment through different pathways. In this review, we analyzed the occurrence of these fluorinated compounds in seven types of products (i.e., refrigerants/propellants, aqueous film-forming foam, cosmetics, food packaging, agrochemicals, pharmaceuticals, coating materials) and discussed their fate in the environment. This is followed by describing the quantity of fluorinated compounds from each source based on available data. Total on- and off-site disposal or other releases of 536 fluorinated compounds in 2021 were analyzed using the data sourced from the U.S. EPA Toxics Release Inventory (TRI). Among the chemicals examined, chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) were the primary contributors in terms of total mass. Upon examining the seven sources of fluorinated compounds, it became evident that additional contributors are also responsible for the presence of organofluorine compounds in the environment. Although various toxic degradation products of fluorinated compounds could form in the environment, trifluoroacetic acid (TFA) was specifically highlighted in this review given the fact that it is a common dead-end degradation product of > 1 million chemicals. This paper ended with a discussion of several questions raised from this study. The path forward was elaborated as well for the purpose of protecting the environment and human health.

Impact of per- and polyfluorinated alkyl substances (PFAS) on the marine environment: Raising awareness, challenges, legislation, and mitigation approaches under the One Health concept

Per- and polyfluorinated alkyl substances (PFAS) have long been known for their detrimental effects on the ecosystems and living organisms; however the long-term impact on the marine environment is still insufficiently recognized. Based on PFAS persistence and bioaccumulation in the complex marine food network, adverse effects will be exacerbated by global processes such as climate change and synergies with other pollutants, like microplastics. The range of fluorochemicals currently included in the PFAS umbrella has significantly expanded due to the updated OECD definition, raising new concerns about their poorly understood dynamics and negative effects on the ocean wildlife and human health. Mitigation challenges and approaches, including biodegradation and currently studied materials for PFAS environmental removal are proposed here, highlighting the importance of ongoing monitoring and bridging research gaps. The PFAS EU regulations, good practices and legal frameworks are discussed, with emphasis on recommendations for improving marine ecosystem management.

Discovery and Mechanism of Novel 7-Aliphatic Amine Tryptanthrin Derivatives against Phytopathogenic Bacteria

Rice bacterial leaf blight is a destructive bacterial disease caused by Xanthomonas oryzae pv. oryzae (Xoo) that seriously threatens crop yields and their associated economic benefits. In this study, a series of improved dissolubility 7-aliphatic amine tryptanthrin derivatives was designed and synthesized, and their potency in antibacterial applications was investigated. Notably, compound 6e exhibited excellent activity against Xoo, with an EC₅₀ value of 2.55 μg/mL, compared with the positive control bismerthiazol (EC₅₀ = 35.0 μg/mL) and thiodiazole copper (EC₅₀ = 79.4 μg/mL). In vivo assays demonstrated that 6e exhibited a significant protective effect on rice leaves. After exposure, the morphology of the bacteria was partially atrophied by SEM. Furthermore, 6e increased the accumulation of intracellular reactive oxygen species, causing cell apoptosis and the formation of bacterial biofilms. All the results indicated that 6e could be a potential agrochemical bactericide for controlling phytopathogenic bacteria.

Research Progress of Benzothiazole and Benzoxazole Derivatives in the Discovery of Agricultural Chemicals

Benzoxazole and benzothiazole have a broad spectrum of agricultural biological activities, such as antibacterial, antiviral, and herbicidal activities, which are important fused heterocyclic scaffold structures in agrochemical discovery. In recent years, great progress has been made in the research of benzoxazoles and benzothiazoles, especially in the development of herbicides and insecticides. With the widespread use of benzoxazoles and benzothiazoles, there may be more new products containing benzoxazoles and benzothiazoles in the future. We systematically reviewed the application of benzoxazoles and benzothiazoles in discovering new agrochemicals in the past two decades and summarized the antibacterial, fungicidal, antiviral, herbicidal, and insecticidal activities of the active compounds. We also discussed the structural-activity relationship and mechanism of the active compounds. This work aims to provide inspiration and ideas for the discovery of new agrochemicals based on benzoxazole and benzothiazole.

Design, Synthesis, and Antifungal/Antioomycete Activity of Thiohydantoin Analogues Containing Spirocyclic Butenolide

Novel fungicidal agents were designed based on the combination of two privileged scaffolds, thiohydantoin and spirocyclic butenolide, which are widely found in natural products. The synthesized compounds were characterized by ¹H NMR, ¹³C NMR, and high-resolution electrospray ionisation mass spectrometry. The in vitro antioomycete activity evaluation showed that most of the compounds exhibited excellent inhibitory activities against different developmental stages in the life cycle of pathogenic oomycete Phytophthora capsici. Compound 5j could inhibit the mycelial growth, sporangium production, zoospore release, and cystospore germination significantly with EC₅₀ values of 0.38, 0.25, 0.11, and 0.026 μg/mL, respectively. The in vivo antifungal/antioomycete bioassay results revealed that the series of compounds generally showed outstanding control efficacies against the pathogenic oomycete Pseudoperonospora cubensis, and compounds 5j, 5l, 7j, 7k, and 7l possessed broad-spectrum antifungal activities against the test phytopathogens. The in vivo protective and curative efficacies against P. capsici of the representative compound 5j were excellent, which were better than those of azoxystrobin. More prominently, 5j significantly promoted the biomass accumulation of the root system and reinforced the cell wall by callose deposition. The pronounced upregulation of immune response-related genes indicated that the active oomycete inhibitor 5j also functioned as a plant elicitor. Transmission electron microscopy observation and the enzyme activity test demonstrated that the mechanism of action of 5j was to bind to the pivotal protein, complex III on the respiratory chain, which resulted in a shortage of energy supply. Molecular docking results exhibited that compound 5j appropriately matched with the Qo pocket and had no interaction with the most commonly mutated site Gly-142, which may be of significant benefit in Qo fungicide resistance management. Compound 5j showed great advantages and potential in oomycete control, resistance management, and induction of disease resistance. A further investigation of 5j with a unique structure might have direct implications for the creation of novel oomycete inhibitors against plant-pathogenic oomycetes.

Quantitative assessment of selective degradation behavior of etoxazole in different classes of organisms by compound-specific isotope analysis

In this paper, the stereoselective degradation and quantitative identification of chiral pesticide etoxazole in organisms with different classes of organisms (soil, chlorella algal fluid and mice) were carried out by compound-specific isotope analysis (CSIA). The degradation behavior and stable isotope fractionation effect of etoxazole in soil, chlorella and mice were investigated. The R-etoxazole degraded faster than S-etoxazole in different classes of organisms. The metabolites M1, M2 and M3 were detected in all three substrates. Biodegradation is the main factor for the change of stable isotope ratio of chiral pesticide etoxazole. Furthermore, the relationship between fractionation value of carbon isotope and residual concentration of etoxazole is established by Rayleigh equation, and the biodegradation rate of etoxazole could be calculated by using CSIA without measuring the concentration of etoxazole. Therefore, the use of CSIA can accurately assess the degradation behavior of pesticide pollution in the environment and provide a certain scientific evidence and technical support in the process of environmental remediation.

Excellent photocatalytic and antibacterial activities of bio-activated carbon decorated magnesium oxide nanoparticles

Green production of nanomaterials are restrict toxic substances and motivated the noxious free environment. Photocatalysis and antibacterial resistance are more promising and efficient fields for their chemical reductants and clean environment. Herein, we adopted a green and simple method for the biosynthesis of MgO NPs using Manilkara zapota as a bio source. Recently, the green synthesis of magnesium oxide nanoparticles has been a keen interest amongst researchers and scientists due to its simplicity eco-friendliness, non-toxic, inexpensive and potential to perform as an antibacterial agent. Activated carbon/Magnesium oxide (AC/MgO) photocatalyst was blended through a simple solution evaporation method. The surface electron microscopy (SEM) study reviles that AC/MgO had smooth and aggregated particles. The Fourier transform infrared (FT-IR) and x-ray diffraction (XRD) study confirms the structural formation and incorporation of nanoparticles into the AC matrix. Results confirmed the flourishing integration of MgO NPs over the activated carbon matrix. The electron movement and valency of AC/MgO photocatalyst reduced the bandgap and their findings were characterized by ultra visible diffuse reflectance spectroscopy (UV-DRS) and x-ray photoelectron spectroscopy (XPS). The blended AC/MgO photocatalyst was analyzed for photodegradation of Rhodamine- B (Rh-B) dye using a UV-visible spectrophotometer. The degradation study projects that the AC/MgO photocatalyst degrades (Rh-B) dye with 99% efficiency under simulated solar irradiation. This efficient degradation of (Rh-B) dye by AC/MgO photocatalyst is ascribed to the synergetic AC as catalytic support and adsorbent and MgO as photocatalyst. Finally, the photocatalytic material shows a better bactericidal effect in both gram-positive bacteria Escherichia coli-745 and gram-negative bacteria Staphylococcus aureus-9779. The AC/MgO photocatalyst is effectively used in bacteriocidal and photocatalytic removal of dyes and can be used for further development of water reuse and bio-medical fields. In addition, this research shows a viable method for synthesizing a cheap and effective AC/MgO for the photocatalytic destruction of organic pollutants.

NtbHLH49, a jasmonate-regulated transcription factor, negatively regulates tobacco responses to Phytophthora nicotianae

Tobacco black shank caused by Phytophthora nicotianae is a devastating disease that causes huge losses to tobacco production across the world. Investigating the regulatory mechanism of tobacco resistance to P. nicotianae is of great importance for tobacco resistance breeding. The jasmonate (JA) signaling pathway plays a pivotal role in modulating plant pathogen resistance, but the mechanism underlying JA-mediated tobacco resistance to P. nicotianae remains largely unclear. This work explored the P. nicotianae responses of common tobacco cultivar TN90 using plants with RNAi-mediated silencing of NtCOI1 (encoding the perception protein of JA signal), and identified genes involved in this process by comparative transcriptome analyses. Interestingly, the majority of the differentially expressed bHLH transcription factor genes, whose homologs are correlated with JA-signaling, encode AtBPE-like regulators and were up-regulated in NtCOI1-RI plants, implying a negative role in regulating tobacco response to P. nicotianae. A subsequent study on NtbHLH49, a member of this group, showed that it's negatively regulated by JA treatment or P. nicotianae infection, and its protein was localized to the nucleus. Furthermore, overexpression of NtbHLH49 decreased tobacco resistance to P. nicotianae, while knockdown of its expression increased the resistance. Manipulation of NtbHLH49 expression also altered the expression of a set of pathogen resistance genes. This study identified a set of genes correlated with JA-mediated tobacco response to P. nicotianae, and revealed the function of AtBPE-like regulator NtbHLH49 in regulating tobacco resistance to this pathogen, providing insights into the JA-mediated tobacco responses to P. nicotianae.

Finding Fluorine: Photoproduct Formation during the Photolysis of Fluorinated Pesticides

The photolysis of pesticides with different fluorine motifs was evaluated to quantify the formation of fluorinated products in buffered aqueous systems, advanced oxidation (AOP) and reduction processes (ARP), and river water. Simulated sunlight quantum yields at pH 7 were 0.0033, 0.0025, 0.0015, and 0.00012 for penoxsulam, florasulam, sulfoxaflor, and fluroxypyr, respectively. The bimolecular rate constants with hydroxyl radicals were 2 to 5.7 × 1010 M-1 s-1 and, with sulfate radicals, 1.6 to 2.6 × 108 M-1 s-1 for penoxsulam, florasulam, and fluroxypyr, respectively. The rate constants of sulfoxaflor were 100-fold lower. Using quantitative 19F-NMR, complete fluorine mass balances were obtained. The maximum fluoride formation was 53.4 and 87.4% for penoxsulam and florasulam under ARP conditions, and 6.1 and 100% for sulfoxaflor and fluroxypyr under AOP conditions. Heteroaromatic CF3 and aliphatic CF2 groups were retained in multiple fluorinated photoproducts. Aryl F and heteroaromatic F groups were readily defluorinated to fluoride. CF3 and CF2 groups formed trifluoroacetate and difluoroacetate, and yields increased under oxidizing conditions. 19F-NMR chemical shifts and coupling analysis provided information on hydrogen loss on adjacent bonds or changes in chirality. Mass spectrometry results were consistent with the observed 19F-NMR products. These results will assist in selecting treatment processes for specific fluorine motifs and in the design of agrochemicals to reduce byproduct formation.

Strategies for the Biodegradation of Polyfluorinated Compounds

Many cite the strength of C–F bonds for the poor microbial biodegradability of polyfluorinated organic compounds (PFCs). However, commercial PFCs almost invariably contain more functionality than fluorine. The additional functionality provides a weak entry point for reactions that activate C–F bonds and lead to their eventual cleavage. This metabolic activation strategy is common in microbial biodegradation pathways and is observed with aromatic hydrocarbons, chlorinated compounds, phosphonates and many other compounds. Initial metabolic activation precedes critical bond breakage and assimilation of nutrients. A similar strategy with commercial PFCs proceeds via initial attack at the non-fluorinated functionalities: sulfonates, carboxylates, chlorines, phenyl rings, or phosphonates. Metabolic transformation of these non-fluorinated groups can activate the C–F bonds, allowing more facile cleavage than a direct attack on the C–F bonds. Given that virtually all compounds denoted as “PFAS” are not perfluorinated and are not alkanes, it is posited here that considering their individual chemical classes is more useful for both chemical and microbiological considerations of their fate.

UV-Vis Activated Cu2O/SnO2/WO3 Heterostructure for Photocatalytic Removal of Pesticides

A three-steps sol–gel method was used to obtain a Cu₂O/SnO₂/WO₃ heterostructure powder, deposited as film by spray pyrolysis. The porous morphology of the final heterostructure was constructed starting with fiber-like WO₃ acting as substrate for SnO₂ development. The SnO₂/WO₃ sample provide nucleation and grew sites for Cu₂O formation. Diffraction evaluation indicated that all samples contained crystalline structures with crystallite size varying from 42.4 Å (Cu₂O) to 81.8 Å (WO₃). Elemental analysis confirmed that the samples were homogeneous in composition and had an oxygen excess due to the annealing treatments. Photocatalytic properties were tested in the presence of three pesticides—pirimicarb, S-metolachlor (S-MCh), and metalaxyl (MET)—chosen based on their resilience and toxicity. The photocatalytic activity of the Cu₂O/SnO₂/WO₃ heterostructure was compared with WO₃, SnO₂, Cu₂O, Cu₂O/SnO₂, Cu₂O/WO₃, and SnO₂/WO₃ samples. The results indicated that the three-component heterostructure had the highest photocatalytic efficiency toward all pesticides. The highest photocatalytic efficiency was obtained toward S-MCh (86%) using a Cu₂O/SnO₂/WO₃ sample and the lowest correspond to MET (8.2%) removal using a Cu₂O monocomponent sample. TOC analysis indicated that not all the removal efficiency could be attributed to mineralization, and by-product formation is possible. Cu₂O/SnO₂/WO₃ is able to induce 81.3% mineralization of S-MCh, while Cu₂O exhibited 5.7% mineralization of S-MCh. The three-run cyclic tests showed that Cu₂O/SnO₂/WO₃, WO₃, and SnO₂/WO₃ exhibited good photocatalytic stability without requiring additional procedures. The photocatalytic mechanism corresponds to a Z-scheme charge transfer based on a three-component structure, where Cu₂O exhibits reduction potential responsible for O₂ production and WO₃ has oxidation potential responsible for HO· generation.