A mesoporous silica nanocarrier pesticide delivery system for loading acetamiprid: Effectively manage aphids and reduce plant pesticide residue

Inhibition mechanism of pectin-modified nano-selenium on Phytophthora capsici and the improvement of the resistance in pepper

The principal disease impacting pepper production is Phytophthora blight, which nano‑selenium (nano-Se) controls well but has high storage requirements and low heat resistance. Varying pectin amounts yielded pectin-modified nano-Se (nano-Se@PT) with 0.1 %, 0.5 %, 1 %, and 2 % concentration. As pectin content grew, nano-Se@PT particle size reduced, zeta potential value rose, and thermogravimetric temperature climbed. The incorporation of nano-Se@PT can improve its stability and thermal resistance at 40 °C and 70 °C. Nano-Se@PT outperformed nano-Se in fungicidal and Phytophthora capsici inhibition. In vitro antifungal experiments showed that nano-Se@PT could significantly inhibit mycelium growth with an EC50 of about 4 mg/L. The particles adsorbed on the surface of mycelium, inducing death by destroying cell membranes, mitochondria, and nuclei. Non-targeted metabolomics analysis showed that nano-Se@PT treatment disrupted the mycelium growth and metabolism and changed amino acids, nucleotides, and sugar levels. In vivo experiments, 2 % nano-Se@PT had the lowest disease index and the best preventive therapy. Rhizosphere soil microbial analysis showed that nano-Se@PT recruited beneficial microorganisms such as Bacteroides, Lactobacillus, and Bifidobacterium in pepper plants, improving their Phytophthora capsici resistance and growth. The findings suggest that nano-Se@PT might be a unique pepper disease control technique and shed light on plant fungal disease management.

Silica Nanoparticles as Versatile Carriers for Nanofertilizers and Nanopesticides: Design and Applications

The application of silica nanoparticles (SNPs) as nanocarriers for delivering nutrients and pesticide components holds great promise, offering the potential to reduce agrochemical usage while enhancing their efficacy. Herein, we initially present the types, synthesis approaches, and structural features of SNPs as nanoagrochemical delivery carriers. Subsequently, the loading and stimulus-responsive release strategies of guest molecules used for preparation of SNPs-based nanofertilizers and nanopesticides are summarized. The applications and advantages of SNPs-based nanoformulations in nutrient delivery, disease and pest management, and weed control are also discussed. Finally, the aspects that should be taken into consideration in future research and application of SNPs-based nanoagrochemicals are highlighted. This review aims to provide novel insights and comprehensive perspectives for researchers and practitioners striving to enhance the efficiency and environmental sustainability of agrochemical products.

Sodium-lignosulfonate-conjugated metal-organic frameworks as dual-stimulus-responsive carriers for improved pesticide targeting

The use of intelligent pesticides that respond to environmental stimuli is a promising strategy for achieving sustainable pest control while mitigating pesticide-related environmental pollution. This study reports the design of a pH and laccase dual-stimulus-responsive pesticide-slow-release composite (IMI@UiO-66@SL). The composite utilises an imidacloprid (IMI)-encapsulated metal-organic framework (MOF; UiO-66) as a nano-carrier and sodium lignosulfonate (SL) as a capping agent. Results show that IMI@UiO-66@SL exhibits excellent IMI release properties in acidic and laccase-rich environments, which closely mimic the physiological and behavioural conditions of termites. Furthermore, compared to the original IMI formulation, IMI@UiO-66@SL exhibits enhanced and prolonged insecticidal activity. Briefly, this study reports a promising approach for the sustainable management of termite colonies.

Dual-stimuli-responsive carboxymethyl chitosan/sodium lignosulfonate microcapsules from oppositely charged biopolymers for smart pesticide release

In this study, we constructed a pH/laccase dual responsive drug delivery system, denoted as IMI@(CMCS+SL)n, capable of modulating wall thickness and drug release via the layer-by-layer deposition of carboxymethyl chitosan (CMCS) and sodium lignosulfonate (SL). The IMI@(CMCS+SL)n microcapsules was characterized by Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), (energy-dispersive X-ray spectroscopy) EDS, X-ray photoelectron spectroscopy (XPS), and dynamic light scattering techniques (DLS) analysis. IMI@(CMCS+SL)n demonstrated not only a high loading capacity (exceeding 90 %) but also exhibited exceptional performance in sustained release and anti-termite activity of IMI. Significantly, IMI@(CMCS+SL)n was responsive to both laccase and pH variations. These results suggest that the distinctive laccase activity and weakly alkaline conditions within the termite gut may serve as triggering factors for the release of IMI by IMI@(CMCS+SL)n. Overall, the pesticide carrier system designed in this research ensures precise pesticide application and enhances the value of natural biomass resources.

Evaluating the impact of neonicotinoids on aquatic non-target species: A comprehensive review

Neonicotinoid insecticides (NNIs) are the fastest-growing class in agricultural protection. They target nicotinic acetylcholine receptors (nAChR) in pests, stimulating the nervous system at low doses and causing paralysis and death at higher concentrations. NNIs are used in crop protection, seed treatment, forestry, agriculture, and flea control in domestic cattle. Effective at lower concentrations and offering long-term control, NNIs are favoured for their systemic activity. However, due to their water solubility, mobility, and moderate persistence, NNIs easily contaminate adjacent aquatic environments via runoff, leaching, or spray drift. While less toxic to vertebrates, their widespread use poses threats to aquatic and terrestrial organisms, causing neurotoxicity, nephrotoxicity, cytotoxicity, genotoxicity, immunotoxicity, hepatotoxicity, endocrine disruption, and reproductive malformations. This review synthesizes research to address knowledge gaps on the environmental impact of NNIs and proposes policies to mitigate their harmful effects on aquatic non-target species.

pH and Pectinase Dual-Responsive Zinc Oxide Core-Shell Nanopesticide: Efficient Control of Sclerotinia Disease and Reduction of Environmental Risks

Sclerotinia sclerotiorum is one of the fungi that cause plant diseases. It damages plants by secreting large amounts of oxalic acid and cell wall-degrading enzymes. To meet this challenge, we designed a new pH/enzyme dual-responsive nanopesticide Pro@ZnO@Pectin (PZP). This nanopesticide uses zinc oxide (ZnO) as a carrier of prochloraz (Pro) and is encapsulated with pectin. When encountering oxalic acid released by Sclerotinia sclerotiorum, the acidic environment promotes the decomposition of ZnO; at the same time, the pectinase produced by Sclerotinia sclerotiorum can also decompose the outer pectin layer of PZP, thereby promoting the effective release of the active ingredient. Experimental data showed that PZP was able to achieve an efficient release rate of 57.25% and 68.46% when pectinase was added or under acidic conditions, respectively. In addition, in vitro tests showed that the antifungal effect of PZP was comparable to that of the commercial Pro (Pro SC) on the market, and its efficacy was 1.40 times and 1.32 times that of the Pro original drug (Pro TC), respectively. Crucially, the application of PZP significantly alleviated the detrimental impacts of Pro on wheat development. Soil wetting experiments have proved that PZP primarily remained in the soil, thereby decreasing its likelihood of contaminating water sources and reducing potential risks to non-target organisms. Moreover, PZP improved the foliar wettability of Pro, lowering the contact angle to 75.06°. Residue analyses indicated that PZP did not elevate prochloraz residue levels in tomato fruits compared to conventional applications, indicating that the nanopesticide formulation does not lead to excessive pesticide buildup. In summary, the nanopesticide PZP shows great promise for effectively managing Sclerotinia sclerotiorum while minimizing environmental impact.

Nanocarrier mediated delivery of insecticides into tarsi enhances stink bug mortality

Current delivery practices for insecticide active ingredients are inefficient with only a fraction reaching their intended target. Herein, we developed carbon dot based nanocarriers with molecular baskets (γ-cyclodextrin) that enhance the delivery of active ingredients into insects (southern green stink bugs, Nezara viridula L.) via their tarsal pores. Nezara viridula feeds on leguminous plants worldwide and is a primary pest of soybeans. After two days of exposure, most of the nanocarriers and their active ingredient cargo (>85%) remained on the soybean leaf surface, rendering them available to the insects. The nanocarriers enter stink bugs through their tarsi, enhancing the delivery of a fluorescent chemical cargo by 2.6 times. The insecticide active ingredient nanoformulation (10 ppm) was 25% more effective in controlling the stink bugs than the active ingredient alone. Styletectomy experiments indicated that the improved active ingredient efficacy was due to the nanoformulation entering through the insect tarsal pores, consistent with fluorescent chemical cargo assays. This new nanopesticide approach offers efficient active ingredient delivery and improved integrated pest management for a more sustainable agriculture.

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.

Biomass-Based, Dual Enzyme-Responsive Nanopesticides: Eco-friendly and Efficient Control of Pine Wood Nematode Disease

Pine wood nematode (PWN) disease is a globally devastating forest disease caused by infestation with PWN, Bursaphelenchus xylophilus, which mainly occurs through the vector insect Japanese pine sawyer (JPS), Monochamus alternatus. PWN disease is notoriously difficult to manage effectively and is known as the "cancer of pine trees." In this study, dual enzyme-responsive nanopesticides (AVM@EC@Pectin) were prepared using nanocoating avermectin (AVM) after modification with natural polymers. The proposed treatment can respond to the cell wall-degrading enzymes secreted by PWNs and vector insects during pine tree infestation to intelligently release pesticides to cut off the transmission and infestation pathways and realize the integrated control of PWN disease. The LC50 value of AVM@EC@Pectin was 11.19 mg/L for PWN and 26.31 mg/L for JPS. The insecticidal activity of AVM@EC@Pectin was higher than that of the commercial emulsifiable concentrate (AVM-EC), and the photostability, adhesion, and target penetration were improved. The half-life (t1/2) of AVM@EC@Pectin was 133.7 min, which is approximately twice that of AVM-EC (68.2 min). Sprayed and injected applications showed that nanopesticides had superior bidirectional transportation, with five-times higher AVM contents detected in the roots relative to those of AVM-EC when sprayed at the top. The safety experiment showed that the proposed treatment had lower toxicity and higher safety for nontarget organisms in the application environment and human cells. This study presents a green, safe, and effective strategy for the integrated management of PWN disease.

Silicon nanoparticles in sustainable agriculture: synthesis, absorption, and plant stress alleviation

Silicon (Si) is a widely recognized beneficial element in plants. With the emergence of nanotechnology in agriculture, silicon nanoparticles (SiNPs) demonstrate promising applicability in sustainable agriculture. Particularly, the application of SiNPs has proven to be a high-efficiency and cost-effective strategy for protecting plant against various biotic and abiotic stresses such as insect pests, pathogen diseases, metal stress, drought stress, and salt stress. To date, rapid progress has been made in unveiling the multiple functions and related mechanisms of SiNPs in promoting the sustainability of agricultural production in the recent decade, while a comprehensive summary is still lacking. Here, the review provides an up-to-date overview of the synthesis, uptake and translocation, and application of SiNPs in alleviating stresses aiming for the reasonable usage of SiNPs in nano-enabled agriculture. The major points are listed as following: (1) SiNPs can be synthesized by using physical, chemical, and biological (green synthesis) approaches, while green synthesis using agricultural wastes as raw materials is more suitable for large-scale production and recycling agriculture. (2) The uptake and translocation of SiNPs in plants differs significantly from that of Si, which is determined by plant factors and the properties of SiNPs. (3) Under stressful conditions, SiNPs can regulate plant stress acclimation at morphological, physiological, and molecular levels as growth stimulator; as well as deliver pesticides and plant growth regulating chemicals as nanocarrier, thereby enhancing plant growth and yield. (4) Several key issues deserve further investigation including effective approaches of SiNPs synthesis and modification, molecular basis of SiNPs-induced plant stress resistance, and systematic effects of SiNPs on agricultural ecosystem.

A highly effective SERS platform formed by the fabrication of Ag@ZIF-8@Au nanoparticles for rapid detection of acetamiprid in environment

The unreasonable spraying and random migration of acetamiprid may cause pollution of crops, soil and water resources in the environment, resulting in threatening ecosystem and human health. However, the monitoring of acetamiprid using mass spectrum in the environment encounters challenges due to high-cost instruments and complex processing time. Herein, we fabricated a rapid and reliable SERS method based on Ag@ZIF-8@Au platforms for tracing acetamiprid residues in the environment. In this method, a MOF material named ZIF-8 is coated with silver nanoparticles and distributed internally between AgNPs and AuNPs to enhance Raman signal, which can enrich pesticide molecules into the hotspots area provided by noble material and helps avoid the oxidation of silver nanoparticles. High sensitivity (LOD of 9.027 × 10-10 M for acetamiprid, and SERS enhancement factor of 4.3 × 107), excellent reproducibility (6.496% or 7.198% RSD for 30 random points) and superior stability (3.127% RSD for 6 weeks) were achieved using the proposed method. Acetamiprid with concentrations from 10-4 to 10-9 M were successfully detected by SERS method. Furthermore, the linear detection models of acetamiprid in different environment matrices (lake water, tea leaves, tea garden soil, oranges and oranges orchard soil) were established and all the correlation coefficient (R2) were higher than or equal to 95%, indicating the excellent adaptability of Ag@ZIF-8@Au platform in environment. The randomly spiked concentrations of acetamiprid were also tested with good recovery values and low relative error values, further confirming the reliability of the detection method.

Quaternized chitosan-based organic-inorganic nanohybrid nanoparticles loaded with prothioconazole for efficient management of fungal diseases with minimal environmental impact

Poor foliar deposition and retention of pesticides results in serious pesticide residues and environmental pollution. Organic-inorganic hybridized nanoparticles (OIHN), combining the advantages of organic and inorganic materials, can be used as carriers to load pesticides for efficient and safe application. Herein, a novel multifunctional OIHN composed of mesoporous silica nanoparticles (MSNs) and cationic chitosan quaternary ammonium salt (HACC) was constructed and used as a delivery system for prothioconazole (PTC). The resultant PTC@MSNs-HACC exhibited a remarkable loading capacity of 39.07 wt% and demonstrated enhanced PTC release (31.47 %) under alkaline conditions. The UV-shielding properties of MSNs efficiently shielded PTC from photodegradation, increasing its photostability by over threefold. The strong positive charge of HACC conferred excellent adhesion of PTC@MSNs-HACC to fungal cell membranes, leading to high deposition on wheat leaves with improved rain-wash resistance (increased by 30 %). Consequently, PTC@MSNs-HACC (EC50: 12.48 mg/L) exhibited superior wheat scab control compared to PTC emulsifiable concentrate (EC50: 28.49 mg/L). Additionally, PTC@MSNs-HACC displayed excellent uptake and transport in plants, ensuring plant safety and reducing toxicity to zebrafish by >1-fold. The potential application of the developed PTC@MSNs-HACC in agricultural production holds significant promise and is anticipated to find widespread use in the future.

High deposition and precise stimulus-response release performance of lignin-coated dendritic mesoporous organosilica nanoparticles for efficient pesticide utilization

The inefficient and improper use of conventional pesticides has prompted the development of targeted and cost-effective pesticide delivery systems, which aim to optimize the efficient utilization of pesticides while minimizing environmental pollution in surrounding areas. In this paper, a dual-stimuli-responsive pesticide slow-release nanopesticide system (NES@DMONs@LGN) was designed in this study, utilizing mesoporous silica (DMONs) as a nanocarrier and lignin (LGN) as a capping agent to encapsulate the pesticide molecules within DMONs. This system enables intelligent release of pesticide molecules while preventing environmental pollution caused by leakage. Additionally, NES@DMONs@LGN exhibit excellent specific loading efficiency. The abundant hydrophilic functional groups in the lignin layer on the surface of NES@DMONs@LGN can establish hydrogen bonds with advanced fatty acids and fatty alcohols present in the waxy epidermis of plants, thereby significantly enhancing carrier wettability and adhesion. Typically, phytophagous lepidopteran pests have an alkaline midgut and possess lignin-degrading enzymes. The NES@DMONs@LGN developed in this study are capable of rapid release under high temperature and alkaline conditions. Therefore, the precise release of pesticide molecules in the target pests can be achieved, thus increasing the actual utilization rate of pesticides. The experimental results demonstrated that NES@DMONs@LGN effectively prevented photodegradation of the active ingredient after 48 h of UV irradiation, resulting in a 3.7-fold improvement in photostability and providing robust UV protection. By encapsulating pesticide molecules with nanocarriers, the release of pesticides in non-targeted environments can be prevented, thereby significantly reducing toxicity to zebrafish. Thus, this study provides a promising solution for sustainable greening of agriculture.

Application of nanopesticides and its toxicity evaluation through Drosophila model

Insects feed on plants and cause the growth of plants to be restricted. Moreover, the application of traditional pesticides causes harmful effects on non-target organisms and poses serious threats to the environment. The use of conventional pesticides has negative impacts on creatures that are not the intended targets. It also presents significant risks to the surrounding ecosystem. Insects that are exposed to these chemicals eventually develop resistance to them. This review could benefit researcher for future development of nanopesticides research. This is because a holistic approach has been taken to describe the multidimensional properties of nanopesticides, health and environmental concerns and its possible harmful effects on non-target organisms and physiochemical entities. The assessment of effects of the nanopesticides is also being discussed through the drosophotoxicology. The future outlooks have been suggested to take a critical analysis before commercialization or formulation of the nanopesticides.

Recent advances in stimuli-response mechanisms of nano-enabled controlled-release fertilizers and pesticides

Nanotechnology-enabled fertilizers and pesticides, especially those capable of releasing plant nutrients or pesticide active ingredients (AIs) in a controlled manner, can effectively enhance crop nutrition and protection while minimizing the environmental impacts of agricultural activities. Herein, we review the fundamentals and recent advances in nanofertilizers and nanopesticides with controlled-release properties, enabled by nanocarriers responsive to environmental and biological stimuli, including pH change, temperature, light, redox conditions, and the presence of enzymes. For pH-responsive nanocarriers, pH change can induce structural changes or degradation of the nanocarriers or cleave the bonding between nutrients/pesticide AIs and the nanocarriers. Similarly, temperature response typically involves structural changes in nanocarriers, and higher temperatures can accelerate the release by diffusion promoting or bond breaking. Photothermal materials enable responses to infrared light, and photolabile moieties (e.g., o-nitrobenzyl and azobenzene) are required for achieving ultraviolet light responses. Redox-responsive nanocarriers contain disulfide bonds or ferric iron, whereas enzyme-responsive nanocarriers typically contain the enzyme's substrate as a building block. For fabricating nanofertilizers, pH-responsive nanocarriers have been well explored, but only a few studies have reported temperature- and enzyme-responsive nanocarriers. In comparison, there have been more reports on nanopesticides, which are responsive to a range of stimuli, including many with dual- or triple-responsiveness. Nano-enabled controlled-release fertilizers and pesticides show tremendous potential for enhancing the utilization efficiency of nutrients and pesticide AIs. However, to expand their practical applications, future research should focus on optimizing their performance under realistic conditions, lowering costs, and addressing regulatory and public concerns over environmental and safety risks.

Nanotechnology-based pesticides: Environmental fate and ecotoxicity

The imminent increase in global food demand inevitably leads to an increase in agricultural practices, with an emphasis on pesticide applications. Nanotechnology-based pesticides, or nanopesticides, have gained importance as they are more efficient and, in some cases, less toxic than their conventional counterparts. However, concerns about these novel products have arisen as evidence about their (eco)safety is controversial. This review aims to: (1) introduce the currently applied nanotechnology-based pesticides and their mechanisms of toxic action; (2) describe their fate when released into the environment, with an emphasis on aquatic environments; (3) summarize available research on ecotoxicological studies in freshwater non-target organisms through a bibliometric analysis; and (4) identify gaps in knowledge from an ecotoxicological perspective. Our results show that the environmental fate of nanopesticides is poorly studied and depends on both intrinsic and external factors. There is also a need for comparative research into their ecotoxicity between conventional pesticide formulations and their nano-based counterparts. Among the few available studies, most considered fish species as test organisms, compared to algae and invertebrates. Overall, these new materials generate toxic effects on non-target organisms and threaten the integrity of the environment. Therefore, deepening the understanding of their ecotoxicity is crucial.

Nano-based smart formulations: A potential solution to the hazardous effects of pesticide on the environment

Inefficient usage, overdose, and post-application losses of conventional pesticides have resulted in severe ecological and environmental issues, such as pesticide resistance, environmental contamination, and soil degradation. Advances in nano-based smart formulations are promising novel methods to decrease the hazardous impacts of pesticide on the environment. In light of the lack of a systematic and critical summary of these aspects, this work has been structured to critically assess the roles and specific mechanisms of smart nanoformulations (NFs) in mitigating the adverse impacts of pesticide on the environment, along with an evaluation of their final environmental fate, safety, and application prospects. Our study provides a novel perspective for a better understanding of the potential functions of smart NFs in reducing environmental pollution. Additionally, this study offers meaningful information for the safe and effective use of these nanoproducts in field applications in the near future.

Stöber method and its nuances over the years

Some characteristics of silica-based materials, such as the control/adjustment of their physical and chemical properties, compatibility, and friendly-use synthesis methods, have held the attention of several scientific groups over the years. This condition of prominence becomes even more evident when we seek these characteristics at the micro- and/or nanoscale. Among existing methods to obtain these micro/nanomaterials, the Stöber method is the focus of this review. This method is known to enable the production of silica micro- or nanoparticles from reagents of medium-easy manipulation under mild conditions using equipment that is common in most laboratories. However, this method has many nuances that must be considered to guarantee accurate results, either in size or distribution, and to ensure result reproducibility. Thus, in this review, we discuss the effects of the primary components used in the synthesis of these materials (i.e., TEOS, ammonia, and water), as well as those of other reaction conditions, such as solvent, temperature, and ionic strength. Therefore, we discuss studies involving the synthesis and characterization of micro- and nanoparticles over the years to establish discussions between their experimental observations and proposed models. This review provides experimental observations about the synthesis of these materials, as well as discussions according to complementary and/or contradictory evidence found over the years. This review seeks to help those who intend to work with this method and provide certain key points that, in our experience, can be important to obtain desired results.