Release Of Pesticides Research Articles

Application of bio-based nanopesticides for pine surface retention and penetration, enabling effective control of pine wood nematodes

The Pine wood nematode disease is a significant biological threat to forestry management and ecological restoration worldwide, with chemical control remaining the primary approach. However, the cryptic nature of pine wood nematodes (PWN) limits the effectiveness of conventional pesticides. This study explores the development of a cellulose network carrier-based nanopesticide (Se@CSM/PDA@AZO-CNF) loaded with selenium nanoparticles, offering dual responsiveness to light and temperature. This innovative design enables the precise release of pesticides under natural conditions, supporting a controlled response. Incorporating selenium nanoparticles into the cellulose-based nanopesticide improved pesticide permeability and deposition in pine trees. The contact angle of pesticides on pine needles decreased by 23°, their resistance to washing increased by 39 %, and cumulative release was significantly enhanced under UV light and low temperatures. Fluorescence tracer experiments demonstrated efficient uptake of Se@CSM/PDA@AZO-CNF nanopesticide by PWN. The hydrogel displayed an LC50 value of 29.1 mg/L against PWN. These findings highlight the potential of this nanopesticide to improve pesticide delivery and efficacy in controlling pine wood nematode disease.

Mesoporous silica nanoparticles based on a dual environmental response corresponding to temperature and α-amylase for the control of Spodoptera litura

The design and development of stimuli-responsive nanocarriers hold the promise of the smart delivery of pesticides to target organisms. Herein, we successfully prepared mesoporous silica nanoparticles using the self-templating method, which were grafted with both N-isopropylacrylamide (NIPAM) and cyclodextrin (CD) and loaded with indoxacarb (IN) to afford a pesticide release system with a dual-stimulated response of temperature and α-amylase, referred to as IN@MSNs@NIPAM@CD. Physicochemical characterisation revealed the successful preparation of IN@MSNs@NIPAM@CD with 46.30 % indoxacarb loading. The results showed that IN@MSNs@NIPAM@CD was able to release IN rapidly in the environment of high temperature and α-Amylase, with excellent dual-responsive property. The UV resistance evaluation showed that IN@MSNs@NIPAM@CD could effectively improve the photodegradation resistance of indoxacarb. Fluorescent inverted microscope showed that FITC@MSNs@NIPAM@CD has excellent uptake and translocation properties in corn plants. Bioactivity tests showed that at 14 d, IN@MSNs@NIPAM@CD (LC50 = 9.83 mg L−1) exhibited higher insecticidal activity and longer effective duration than IN@EC (LC50 = 14.64 mg L−1). Acute toxicity test revealed that the IN@MSNs@NIPAM@CD nanoparticles were less acutely toxic to earthworms, zebrafish, BEAS-2B cells and MSNs@NIPAM@CD nanocarriers were safe for the growth of corn. Thus, the dual-responsive nano-controlled-release formulation of IN@MSNs@NIPAM@CD can provide an effective way of achieving the precise delivery and reduced use of pesticides.

Enhanced and rapid remediation of chlorpyrifos from aqueous phase by amine modified mesoporous silica SBA-15: A systematic investigation on sorption kinetics and mechanistic studies

Pesticides have become a necessary remedy of contemporary agricultural methods. However, the release of excess pesticides to the water bodies is a growing concern worldwide. Chlorpyrifos (CP), an organophosphate based pesticide used for nearly 50,000 tonnes per year globally, has significantly affected the ecosystem. Herein, we have reported that (3-Aminopropyl)triethoxysilane functionalized SBA-15 (ASBA-15) as an efficient adsorbent to remove CP from its aqueous solution to an extent of 1814 mg g−1 within 20 min. The uptake behavior was studied in detail as a function of adsorbent dosage, contact time, and concentration levels of CP. The adsorption findings were well-fitted into the Langmuir isotherm model and pseudo-second-order kinetics. The estimated values of ΔH0 and ΔS0 revealed the exothermic and spontaneous nature of the process. The XRD reflections between 2 θ = 0.90–1.8o, surface area in the ranges of 781–435 m2 g−1 and pore diameters between 7.2 and 6.0nm indicated the mesoporous as well as stable structure for SBA-15 and ASBA-15 materials at different stages of studies. FT IR studies evidenced the presence of the ‒NH group at 1541 cm−1 in ASBA-15. Thermogravimetric analysis results supported the grafting of the ‒NH group onto ASBA-15 as well as the efficient adsorption of CP. The appearance of characteristic vibration of CP at 1513 cm−1 in CP@ASBA supported the entrapment of CP within ASBA-15. The adsorption and desorption of CP by ASBA-15 were accomplished for five cycles without significant mass loss, which demonstrated the reusability, stability and reversible nature of the material.

Chitin nanocrystal Pickering emulsions for sustainable release pesticide microencapsulation with superior leaf adhesion and enhanced safety

Traditional pesticides often exhibit high non-target toxicity, poor stability, short persistence, and susceptibility to wash-off by rain. Pesticide microencapsulation represents a significant advancement in formulation strategies, addressing safety and sustainability concerns associated with conventional pesticides. This study explores the utilization of biodegradable chitin nanocrystals (ChNCs), prepared via acid hydrolysis, for the development of pesticide microcapsules. Specifically, ChNCs were employed to emulsify molten pesticides, followed by interfacial polymerization to fabricate pesticide-loaded microcapsules. Using molten emulsification and Pickering emulsion templates offer a simple and solvent-free approach for microcapsule preparation, eliminating the need for conventional surfactants. The microcapsules displayed a size distribution ranging from hundreds of nanometers to several micrometers, which could be tuned by adjusting the ChNCs content. These microcapsules demonstrated remarkable properties, including a high pesticide loading capacity (reaching 78.7% for lambda-cyhalothrin), excellent storage stability, and enzyme-responsive release behavior. Furthermore, the abundant positive charges enhanced the interaction between the microcapsules and leaf surfaces, leading to improved pesticide retention. Microencapsulation reduces acute insecticidal activity of pesticides due to the slow-release effect; however, field experiments provide compelling evidence that microcapsule formulations significantly prolong pesticide efficacy compared to conventional formulations. Additionally, microencapsulation significantly improved the safety of pesticides, with the LC50 increasing from 0.0116 mg/L to 3.75 mg/L. Overall, this study introduces a promising method for pesticide microencapsulation using ChNCs Pickering emulsion, highlighting its potential advantages and providing valuable insights for the development of environmentally friendly and novel pesticide formulations.

Fabrication of Novel Porous Nano-pesticides by Modifying MPN onto Cu-TCPP MOFs to Enhance Bactericidal Efficacy and Modulate Its Bioavailability.

Nano-pesticides have attracted much attention in the field of agriculture, due to existing problems such as decreased bactericidal effect and poor adhesion. An environmentally friendly metal porphyrin (Cu-TCPP)-based nanocarrier pesticide release of diniconazole (DIN) was designed to enhance bactericidal efficacy and modulate its bioavailability in a multidimensional manner by constructing a metal phenolic network (MPN) encapsulation. The introduction of the MPN prevents the DIN from prematurely escaping from the Cu-TCPP@DIN@MPN in the environment and gives it strong interfacial adhesion to resist rain washing. The resulting Cu-TCPP@DIN@MPN nanoparticles (NPs) showed a lamellar stacked embedded structure, which improved the inhibition of Fusarium oxysporum (90.9%) and photostability (67.2%), while they do not affect healthy plant growth and meet the relevant food safety requirements for DIN residues. This work provides new ideas for the development of superior photostable, adhesive, rainwater erosion-resistant, and sustainable nanocarrier pesticides.

Nano-pesticide delivery system based on UiO-66 with pH sensitivity for precise control of Spodoptera frugiperda.

Metal-organic frameworks have the advantages of easy synthesis, high loading capacity and good biocompatibility, making them essential materials for constructing pesticide nano-delivery systems. In this study, a pH-responsive nano-controlled-release formulation Chl@UiO-66 was prepared using UiO-66 as the nano-scale carrier for adsorbing chlorantraniliprole (Chl). The appearance, pesticide loading, release behaviour, insecticidal activity, long-term control efficacy and safety of Chl@UiO-66 for non-target organisms were extensively evaluated. The results showed that the prepared Chl@UiO-66 was a regular octahedron with a uniform particle size of 230 nm and pesticide loading of 15.62%. The release of pesticides under alkaline conditions was superior to that under acidic and neutral conditions, which showed pH-responsive performance. Chl@UiO-66 had an excellent ability to protect pesticides from ultraviolet degradation. Compared with chlorantraniliprole suspension concentrate, Chl@UiO-66 had a better control effect against Spodoptera frugiperda and long-term control efficacy. The prepared nano-controlled-release formulation had low toxicity to zebrafish, earthworms and human BEAS-2B cells. Chl@UiO-66 is a new pesticide formulation with high efficacy and low toxicity that provides a smart controlled-release solution. © 2024 Society of Chemical Industry.

Role of nanomaterials in modern agriculture

Agriculture is a foundation of several emerging countries, and it is one of the most economically significant drivers. Farmers, consumers, and the environment are all at risk as a result of the increased usage of mineral fertilizers and harmful pesticides. Over the last few years, substantial research into the application of Nanotechnology to boost agricultural productivity has been undertaken. Nanoparticles (NPs) have been discovered to be beneficial as nanopesticides, nanobiosensor, nanofertilizers, and nanoremediation in agrifood production. Nutrients, pesticides, fungicides, and herbicides are compacted with a variety of NPs to facilitate the progressive release of fertilisers and pesticides, resulting in exact dose accessibility to plants. Nanofertilizers improve nutrient utilization, reduce nutrient deficiencies, reduce soil toxicity, and lessen the negative consequences of overdosing, all while reducing treatment frequency. Nanoformulations are used in agriculture to boost germination of seed, reduce nutrient losses in fertilization, reduce the amount of pesticides dispersed, aid water and nutrient management, and. This review also discusses various challenges and concerns about pesticide product development, formulation, and toxicity for ecologically friendly and sustainable agriculture.

High-performance metal-organic frameworks for efficient adsorption, controlled release, and membrane separation of organophosphate pesticides

Metal-organic frameworks (MOFs) are considered good choices for the absorption, separation, and release of various substances. The rapid increase in the number of MOFs being produced makes it impractical to conduct experimental research to identify the most promising candidates in these areas. Therefore, computational screening has emerged as a robust approach. We employed this approach to identify the most efficient MOFs for the removal, separation, and controlled release of organophosphorus pesticides, including diazinon, chlorpyrifos, and chlorpyrifos-methyl. From a database of approximately 14,000 MOFs, 584 MOFs with the largest cavity diameters were used in the screening process to evaluate promising candidates for each pesticide. Monte Carlo simulations were used to estimate the pesticide uptake capacities and isosteric heats of the selected MOFs. The structural properties of MOFs were correlated with their adsorption capacities and isosteric heats. Computational screening identified 325, 330, and 450 MOFs as potential absorbents and carriers for diazinon, chlorpyrifos-methyl, and chlorpyrifos, respectively. Additionally, it proposed 235, 254, and 135 MOFs as membranes for the effective separation of these organophosphorus pesticides. The reactivity of the pesticides was explored using quantum mechanics calculations. Molecular dynamics simulations of the top three MOFs with high uptake capacities for each pesticide were performed and analyzed to understand the interactions between the MOF, pesticide, and water molecules. The solvation-free energies of the pesticides were calculated for various solvents to identify the most effective solvent for desorbing pesticides from the MOFs, thereby enabling MOF regeneration.

Exploring the influence of polymers on soil ecosystems: prospective from agricultural contexts

The utilization of advanced polymeric materials has indeed emerged as a significant trend in sustainable agriculture, offering a range of innovative applications aimed at enhancing productivity, minimizing environmental impact, and promoting resource efficiency. Smart polymeric materials enable the controlled release of pesticides, herbicides, and fertilizers, thereby enhancing their efficacy while reducing the quantities needed. Superabsorbent polymeric materials act as soil conditioners, assisting in alleviating the negative impacts of drought by retaining moisture and enhancing soil structure. This fosters improved plant growth and resilience in water-scarce environments. Polycationic polymers play a role in plant bioengineering, facilitating genetic transformation processes aimed at enhancing crop productivity and disease resistance. Advanced polymeric systems contribute to the arsenal of precision agriculture tools by enabling precise delivery and targeted application of agricultural inputs. This approach enhances resource efficiency, reduces waste, and minimizes environmental impact while optimizing crop yields. In reviewing recent developments in the design and application of advanced polymeric systems for precision agriculture, several key considerations emerge.

A pH-responsive MOFs@MPN nanocarrier with enhancing antifungal activity for sustainable controlling myclobutanil release

The pH-responsive metal–organic framework (MOF) nanocarriers for sustainable controlled release of pesticides is promising in agricultural production owing to their long duration, high loading efficiency and antimicrobial activity. In this work, myclobutanil (MYC) was loaded into an Ag-based MOF (Ag-TCPP), and modified with a metal-phenolic network (MPN) via in-situ polymerization to construct a pH-responsive nano-delivery system (Ag-TCPP@MYC@MPN). Ag-TCPP@MYC@MPN presented a disordered nanoflower structure and many active sites with potential enhanced loading activity. The cumulative release rates of nanoparticles at pH 4.96, 7.5, and 8.5 were 52.6 %, 62.6 % and 80.0 %, respectively. Hence, Ag-TCPP@MYC@MPN has slow release rate and pH responsiveness. The antifungal activity of Ag-TCPP@MYC@MPN was significantly enhanced, and the bacteriostatic rate reached 81.8 %. This enhancement may be attributed to the synergistic antibacterial effect between tannic acid and Ag+. Safety experiments showed the nanoparticles had no inhibitory effect on the germination of Pakchoi seeds, and the pesticide residues of Ag-TCPP@MYC@MPN did not exceed the food safety standards. This work offers a new potential to develop improved responsive stimulus nanocarriers for sustainable controlled release of MYC.

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.

Adduct of Pesticide and Lignocellulosic Waste via Cleavable Silaketal Linkages for Agricultural Double Reduction.

The abuse of hazardous agrochemicals leads to excessive toxic agricultural emissions, posing a tremendous threat to the natural surroundings and human well-being. In practice, the amount of pesticides in protecting crops is often far less than that lost into the environment through evaporation and leaching. Minimizing the use of pesticides as well as improving their use efficiency has been included in the policy of "agricultural double reduction," besides replacing the chemical fertilizer with straw returning. Here, we establish a strategy for controlling pesticide release from the lignocellulosic waste based on the stimulus-responsive cleavage of silaketal linkages. Noting that the cleavage of the silaketal linkages relies heavily on the substituent groups on silicon atoms, this pesticide-releasing system has the advantages of predictable service life and less environmental pollution in a desired time window. Instead of lengthy laboratory synthesis, outdoor instant synthesis can be conveniently realized with the help of a photothermal heating apparatus. After utilization, both silaketal linkages and lignocellulosic residuals are eco-friendly and can be a source of nutrients for soil. Referring to agricultural double reduction, this type of pesticide formulation is coined as a competitive approach to minimize pesticide pollution along with straw returning.

Size-dependent effect on controllable release and field insecticidal efficacy of diamide insecticide polylactic acid microspheres delivery systems against Ostrinia nubilalis

New nano/microcarriers of pesticides represent a highly promising novel field for sustainable pest management. However, despite extensive laboratory research, few studies on the design and evaluation of nanopesticides for field applications exist. In this study, we present a straightforward and green synthetic method of ultrasonic-assisted and hydrogen-bonded self-assembly at the oil-water interface for the synthesis of polylactic acid (PLA) microspheres encapsulating chlorantraniliprole (CAP), with precise control over the size of the microspheres. The resulting CAP-loaded PLA microspheres (CAP-PLA MS) exhibit both high pesticide encapsulation efficiency and stability in natural environments. It has been determined that non-Fickian diffusion mainly controls pesticide release, thus enabling dynamic control over molecular transport speeds. Importantly, our functional CAP-PLA MS demonstrates superior sustained pesticide release performance under both laboratory and field conditions while maintaining better exceptional insecticidal efficacy than normal CAP in controlling O. nubilalis at a concentration of 30 or 45 g/ha. Consequently, we propose that our functional PLA microspheres could serve as ideal pesticide carriers in the sustained treatment of O. nubilalis.

Controlled release formulations of organophosphorus pesticides based on ecofriendly novel and conventional matrices for agro-environmental sustainability

Controlled release formulations (CRFs) of the organophosphorus pesticides diazinon and dichlorvos were prepared from a novel cow dung ash (CDA) matrix and the more conventional starch (STA) matrix. Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and X-ray diffraction (XRD) were used to characterize the CRFs. FTIR and XRD spectral data provide evidence for pesticide-matrix interactions fundamental to observed matrix surface binding and pesticide release behaviour in water and soil environments. Properties evaluation of the CRFs reveal similar magnitudes of loading capacity and encapsulation efficiency of CDA- and STA-based CRFs of both pesticides, while the order CDA > STA prevails in matrix porosity and swelling ability. Technical grade (TG) and the CRF-encapsulated pesticides exhibit “burst” release profiles in water; pesticide quantities released at similar lengths of time follow the order TG >> STA-CRF > CDA-CRF, thus revealing the capacity of the CRFs to constrain the active ingredients from free mobility, with CDA-CRF being the more slightly efficacious. The Korsmeyer-Peppas equation reasonably models pesticide release from both CRFs into water, giving n values consistent with both water diffusion into the matrix and matrix relaxation as kinetically important in both matrices. Soil column experiments demonstrate the potential of the CFRs to mitigate ground water pollution. Overall, the results show that CDA- and STA-based CRFs of both pesticides have roughly the same potency for pesticide controlled release and ground water pollution mitigation. Deployment of these CFRs can contribute to the drive for agro-environmental sustainability, while the use of CDA, a waste material, as a matrix in controlled pesticide delivery would resonate with sustainable bioresource utilization.

Redox/pH Dual-Responsive Fluorescent Nanoparticles for Intelligent Pesticide Release and Visualization in Gray Mold Disease Synergistic Control.

An intelligent delivery nanoformulation could enhance the utilization efficacy, uptake, and translocation of pesticides in plants. Herein, a redox/pH-triggered and fluorescent smart delivery nanoformulation was designed and constructed by using hollow mesoporous organosilica nanoparticles (HMONs) and ZnO quantum dots as the nanocarrier and capping agent, respectively. Boscalid was further loaded to generate Boscalid@HMONs@ZnO with a loading rate of 9.8% for controlling Botrytis cinerea (B. cinerea). The quantity of boscalid released by Boscalid@HMONs@ZnO in a glutathione environment or at pH 3.0 was 1.3-fold and 1.9-fold higher than that in a neutral condition. Boscalid@HMONs@ZnO has 1.7-fold the toxicity index of boscalid technical against B. cinerea in antifungal experiments. Pot experiments revealed that the efficacy of Boscalid@HMONs@ZnO was significantly enhanced more than 1.27-fold compared to commercially available water-dispersible granules of boscalid. Due to the fluorescence properties of Boscalid@HMONs@ZnO, pesticide transport's real-time monitoring of pesticide translocation in tomato plants could be observed by confocal laser scanning microscopy. Fluorescence images revealed that HMONs@ZnO had been effectively transported via treated leaves or roots in tomato plants. This research showed the successful application of HMONs@ZnO as a nanocarrier for controlling disease and offered an effective avenue to explore the real-time tracking of pesticide translocation in plants.

Preliminary Evaluation of Historical used Pesticides in Quercus robur Wood in Belgium: a Negative Finding.

Historically used pesticides poses a threat to biodiversity while their release pathways remain unclear. Trees could be a potential release source due to their long lifespan. This study examined 38 samples to assess pesticide concentrations in pedunculate oak from Belgium. Low concentrations of procymidone were detected in two samples from one stump. Our findings suggest that accumulations of historically used pesticides in pedunculate oaks within forests are improbable. We conclude that leaving dead wood poses no risks for pesticide release to the environment. However, further research involving diverse tree species and regions is needed to refine and validate this conclusion.

A novel approach to managing facility airborne diseases: suppressing air pathogens with smoke aerosols generated from fungicide phase transition.

Environmental microorganisms are major contributors to the development and spread of disease. Chemical disinfection can inhibit pathogens and play a preventive role against diseases. In agriculture, prolonging the floating time of chemical pesticides in the air has a positive effect on the control of airborne diseases. However, the interaction of chemical pesticides with airborne pathogens is not yet known. Here, triazole fungicide was transformed into stable smoke aerosols in order to assess the feasibility of employing phase transition release pesticides for air disinfection. The phase transition had a minimal impact on hexaconazole (Hexa) and myclobutanil (Mycl), with their smoke formation rates remaining consistently >90%. In microscopic morphology, triadimenol (Tria) and epoxiconazole (Epox) are solid, and tebuconazole (Tebu), Hexa, Mycl and difenoconazole (Dife) are liquid. Liquid smoke has advantages over solid smoke in the inhibition of environmental pathogens. The floatability and spatial distribution of fungicide aerosol were optimized by the combination of smoke particles with different properties, so that the fungicide aerosol could meet the conditions of practical application. In practical applications, smoke exhibits a gentler deposition process at the target interface compared to spray, along with a more homogeneous distribution of fungicides. Moreover, fungicide smoke demonstrates superior control efficacy and leaves behind lower residual amounts on fruit. In conclusion, the implementation of fungicide phase transition as a smoke aerosol offers a viable approach to effectively suppress pathogen aerosols and enhance the control of airborne diseases. © 2024 Society of Chemical Industry.

CURRENT STATUS OF THE LEGAL FRAMEWORK IN THE PLANT PROTECTION AND ECOLOGY AND HYGIENE MONITORING DOMAIN IN UKRAINE

Presently chemical plant protection products are an inseparable part of agriculture. They have not only their main purpose of plant assistance, but they also have the potential risk of negative impact on biocenosis species (birds, bees, soil microflora, algae, etc.) and the human body and its health respectively. The purpose of our study was to aggregate data on the existing legal framework of plant protection products in Ukraine and assess their ecology and hygiene monitoring. For analysis of the plant chemical protection, we used as the basic documents the regulatory framework of domestic legislation in toxicological and hygiene, ecology assessment, and ecology and hygiene monitoring domains. Currently, many laws and legal acts regulate the use of pesticides by state and private agricultural farms in Ukraine. This number of documents covers not only pre-registration studies of pesticides but also their post-registration monitoring in the environment. The key entities that control potential negative risks of these products through the regulations are the State Emergency Service, Ministry of Environmental Protection, Ministry of Health, Ministry of Housing and Communal Services, Ministry of Agriculture Policy, State Agency of Water Resources, State Committee of Land Resources, State Agency of the Forest Resources. However, the impact of xenobiotics on non-target species of the ecosystem is currently quite underestimated. The decline in biodiversity directly depends on the condition of the environment and the negative impact on it. Instances of acute oral, inhalation, or dermal poisoning of birds, bees, and aquatic invertebrates with pesticides are quite common and among the factors that affect public health. That is why ecology and hygiene monitoring is essential in line with the assessment of the risks of the inappropriate release of pesticides. These should be treated as a critical component of managing environmental sustainability and safety for public health. The implementation of global approaches to monitoring and controlling the post- registration impact of pesticides on the ecology and hygiene in Ukraine can also take into account the far-reaching consequences of their negative impact, accumulation, and environmental pollution. As a result, this will help to avoid adverse impacts on animal, insect, and bird populations, as well as human health.

Improving the efficiency and environmental safety of emamectin benzoate through a pH-responsive metal–organic framework microencapsulation strategy

Herein, we developed a technique for loading nanopesticides onto Metal-Organic Frameworks (MOFs) to control Spodoptera litura. The average short-axis length of the synthesized carrier emamectin benzoate@PCN-222 @hyaluronic acid (EB@PCN-222 @HA) was ∼40 nm, with an average long-axis length of ∼80 nm. This enabled the manipulation of its size, contact angle, and surface tension on the surface of leaves. Pesticide-loading capacity, determined via thermogravimetric analysis, was measured at ∼16 %. To ensure accurate pesticide release in the alkaline intestine of Spodoptera litura, EB@PCN-222 @HA was engineered to decompose under alkaline conditions. In addition, the carrier delayed the degradation rate of EB, enhancing EB’s stability. Loading Nile red onto PCN-222 @HA revealed potential entry into the insect body through feeding, which was supported by bioassay experiments. Results demonstrated the sustained-release performance of EB@PCN-222 @HA, extending its effective duration. The impact of different carrier concentrations on root length, stem length, fresh weight, and germination rate of pakchoi and tomato were assessed. Promisingly, the carrier exhibited a growth-promoting effect on the fresh weight of both the crops. Furthermore, cytotoxicity experiments confirmed its safety for humans. In cytotoxicity assays, PCN-222 @HA showed minimal toxicity at concentrations up to 100 mg/L, with cell survival rates above 80 %. Notably, the EB@PCN-222 @HA complex demonstrated reduced cytotoxicity compared to EB alone, supporting its safety for human applications. This study presents a safe and effective approach for pest control using controlled-release pesticides with extended effective durations.

Fabrication of zein-coated brush-like silica nanocarriers for high foliage deposition and responsive release of pesticide

Responsive release systems have received extensive attention to enhance pesticide utilization efficiency and reduce environmental pollution. In this study, pH/GSH dual responsive release system based on brush-like silica (bSiO2) carriers was constructed to enhance the utilization of pesticides. The bSiO2 carriers present core-shell structure, length of 550 nm, diameter of 350 nm and shell thickness of 100 nm. The carrier had a high pesticide loading (20.0 %, w/w) for dinotefuran (Din). After loading Din, zein was covalently linked with cysteine-bridge to seal the loaded pesticides (namely Din@bSiO2@Zein). The Din@bSiO2@Zein exhibited superior foliar affinity, retention and photostability, and retention rate still remain above 95 % with 220 min UV irradiation. Din@bSiO2@Zein displayed pH/GSH responsive release and the cumulative release within 92 h was up to 81 % under pH=9/CGSH=6 mM, mimicking the microenvironment of lepidopteran. The Din@bSiO2@Zein possessed good control efficacy against Plutella xylostella. Appreciably, Din@bSiO2@Zein could be transported bi-directionally to various regions of tobacco plants within 24 h, which had potential to promote pesticide efficacy. This work offers a strategy to minimize the pesticide dosage and encourage sustainable agricultural development.