Uptake and Distribution of Fenoxanil-Loaded Mesoporous Silica Nanoparticles in Rice Plants

Agriculture and environmental management through nanotechnology: Eco-friendly nanomaterial synthesis for soil-plant systems, food safety, and sustainability

Through the advancement of nanotechnology, agricultural and food systems are undergoing strategic enhancements, offering innovative solutions to complex problems. This scholarly essay thoroughly examines nanotechnological innovations and their implications within these critical industries. Traditional practices are undergoing radical transformation as nanomaterials emerge as novel agents in roles traditionally filled by fertilizers, pesticides, and biosensors. Micronutrient management and preservation techniques are further enhanced, indicating a shift towards more nutrient-dense and longevity-oriented food production. Nanoparticles (NPs), with their unique physicochemical properties, such as an extraordinary surface-to-volume ratio, find applications in healthcare, diagnostics, agriculture, and other fields. However, concerns about their potential overuse and bioaccumulation raise unanswered questions about their health effects. Molecule-to-molecule interactions and physicochemical dynamics create pathways through which nanoparticles cause toxicity. The combination of nanotechnology and environmental sustainability principles leads to the examination of green nanoparticle synthesis. The discourse extends to how nanomaterials penetrate biological systems, their applications, toxicological effects, and dissemination routes. Additionally, this examination delves into the ecological consequences of nanomaterial contamination in natural ecosystems. Employing robust risk assessment methodologies, including the risk allocation framework, is recommended to address potential dangers associated with nanotechnology integration. Establishing standardized, universally accepted guidelines for evaluating nanomaterial toxicity and protocols for nano-waste disposal is urged to ensure responsible stewardship of this transformative technology. In conclusion, the article summarizes global trends, persistent challenges, and emerging regulatory strategies shaping nanotechnology in agriculture and food science. Sustained, in-depth research is crucial to fully benefit from nanotechnology prospects for sustainable agriculture and food systems.

Pore engineering of micro/mesoporous nanomaterials for encapsulation, controlled release and variegated applications of essential oils

Essential oils have become increasingly popular in fields of medical, food and agriculture, owing to their strongly antimicrobial, anti-inflammation and antioxidant effects, greatly meeting demand from consumers for healthy and safe natural products. However, the easy volatility and/or chemical instability of active ingredients of essential oils (EAIs) can result in the loss of activity before realizing their functions, which have greatly hindered the widely applications of EAIs. As an emerging trend, micro/mesoporous nanomaterials (MNs) have drawn great attention for encapsulation and controlled release of EAIs, owing to their tunable pore structural characteristics. In this review, we briefly discuss the recent advances of MNs that widely used in the controlled release of EAIs, including zeolites, metal-organic frameworks (MOFs), mesoporous silica nanomaterials (MSNs), and provide a comprehensive summary focusing on the pore engineering strategies of MNs that affect their controlled-release or triggered-release for EAIs, including tailorable pore structure properties (e.g., pore size, pore surface area, pore volume, pore geometry, and framework compositions) and surface properties (surface modification and surface functionalization). Finally, the variegated applications and potential challenges are also given for MNs based delivery strategies for EAIs in the fields of healthcare, food and agriculture. These will provide considerable instructions for the rational design of MNs for controlled release of EAIs.

Synthesis and Characterization of Mesoporous Silica Nanoparticles Loaded with P-Cymene against Rice Bacterial Blight

Mesoporous silica nanoparticles (MSNs) can be used as carrier materials for the controlled release of pesticides while reducing their negative environmental impact. In this study, we screened an active ingredient, p-cymene (PC), with an excellent inhibitory effect on rice bacterial blight. Subsequently, the PC was successfully loaded onto MSNs via physisorption (PC@MSNs). PC@MSNs, characterized by a regular spherical shape, smooth surface, and an MSN average size of 262.9 nm, achieved an 8.6% drug loading capacity. The release kinetics of the PC from the PC@MSNs demonstrated a sustained release (288 h) pattern influenced by drug diffusion. The efficacy of the PC@MSNs against Xanthomonas oryzae pv. Oryzae paralleled those of PC. Acute toxicity assays revealed that the PC@MSNs were less toxic to aquatic life (LC50 = 257.867 mg/L) and that the formulation showed no adverse effects on rice seedling growth. In summary, these results suggest that PC@MSNs can broaden PC's scope of application in managing rice diseases.

In-situ quantitative prediction of pesticide residues on plant surface by ATR-FTIR technique coupled with chemometrics

Pesticide residues on plant surfaces pose a severe threat to food security, yet most research has focused on monitoring the liquid matrix, with few reports conducting in-situ analysis of the residues. This study was the first to attempt to utilize portable attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) for in-situ characterization of broad-spectrum fungicide boscalid residues on plant surfaces. ATR-FTIR scanning of tomato fruits with pre-determined concentrations of boscalid residues was conducted without any pre-treatment, and the obtained spectra were then processed using chemometrics methods. The results demonstrated a negative correlation between the residual concentrations and their corresponding absorption intensities of several well-resolved peaks from the spectra, resulting in a high accuracy of 93.33% for the classification model created by probabilistic neural network (PNN) coupled with principal component analysis (PCA). By employing correlation analysis and the interval partial least squares method (iPLS), quantitative analysis was conducted on the wavenumber ranges of 1000-1800 cm-1 and 2700-2900 cm-1 from the spectra. The regression model, established through partial least squares regression (PLSR), demonstrated exceptional performance with an R2 value of 0.80, RMSE of 1.02 μg/cm2, RPD of 2.0, and RPIQ of 2.1 for validation. Meanwhile, the detection limit (LOD) of the model was calculated as 3.06 μg/cm2. This report highlights the potential of using portable ATR-FTIR for conducting qualitative and quantitative monitoring of pesticide residues both in-situ and on-site. It also provides references for other measuring techniques.

Application of hollow fiber-protected liquid-phase microextraction combined with GC-MS in determining Endrin, Chlordane, and Dieldrin in rice samples

This paper introduces a novel and minimized sample preparation technique based on hollow fiber-protected liquid-phase microextraction that can be used in joint with gas chromatography-mass spectrometry (GC-MS) detection to extract three organochlorine pesticides-Endrin, Chlordane, and Dieldrin-from rice samples. To that end, a single-walled carbon nanotube (SWCNT) and a proper ionic liquid (IL) were ultrasonically dispersed and injected into the lumen of hollow fiber as the extraction phase for preconcentrating and extracting the target analytes from the rice samples. The effects of the type of nanoparticles, ILs, and desorption solvent on the efficiency of extracting the analytes were investigated based on the one-factor-at-a-time (OFAT) approach. In addition, other parameters influencing the extraction procedure were optimized using an experimental design that decreased the number of experiments, reagent consumption, and costs. Under optimized conditions, the limits of detection and quantification in determining mentioned pesticides varied between 0.019-0.029 and 0.064-0.098 ng mL-1, respectively. The calibration graphs to measure Endrin, Chlordane, and Dieldrin were linear over the concentration range of 0.064-13.2, 0.098-16.7, and 0.092-11.4 ng mL-1, respectively. The relative standard deviations for inter-day and intra-day analysis were below 7.06 and 4.75% for the triplicate determination of three organochlorine pesticides. Besides, the relative recoveries and standard deviations of Endrin, Chlordane, and Dieldrin for analyzing several Iranian rice samples were between 86.0-92.9% and 4.5-5.8%, respectively. The results were compared with other similar works in literature, proving that the proposed method is efficient and useful for routine monitoring of organochlorine compounds in food samples.

Recent Advances in Nanoparticle-Mediated Co-Delivery System: A Promising Strategy in Medical and Agricultural Field

Drug and gene delivery systems mediated by nanoparticles have been widely studied for life science in the past decade. The application of nano-delivery systems can dramatically improve the stability and delivery efficiency of carried ingredients, overcoming the defects of administration routes in cancer therapy, and possibly maintaining the sustainability of agricultural systems. However, delivery of a drug or gene alone sometimes cannot achieve a satisfactory effect. The nanoparticle-mediated co-delivery system can load multiple drugs and genes simultaneously, and improve the effectiveness of each component, thus amplifying efficacy and exhibiting synergistic effects in cancer therapy and pest management. The co-delivery system has been widely reported in the medical field, and studies on its application in the agricultural field have recently begun to emerge. In this progress report, we summarize recent progress in the preparation and application of drug and gene co-delivery systems and discuss the remaining challenges and future perspectives in the design and fabrication.

Engineered silica nanomaterials in pesticide delivery: Challenges and perspectives

Over the past decade, nanopesticide has been developed rapidly for exploring effective and safe alternatives to conventional pesticides with significant drawbacks and risks. Many nanotechnologies, including pesticide nanoemulsions, polymer-based nanopesticides, and metal/metal oxide nanoparticle-based pesticides have emerged and are extensively reviewed. Engineered silica nanomaterials (ESNs) have also shown promising potential as carriers in nanopesticides for modern agriculture. However, there are limited reviews specifically on ESN-based nanopesticides. Herein, we provide a comprehensive review on the recent progress of ESN-based nanopesticide technologies. An introduction of synthetic technology, formation mechanism, and surface engineering technology is firstly presented. Then, the advantages of ESN-based pesticide formulation and their structure-function-relationship are illustrated in detail. Finally, our perspectives on challenges and future research in ESN-based nanopesticide development are discussed.

Development of clove oil based nanoencapsulated biopesticide employing mesoporous nanosilica synthesized from paddy straw via bioinspired sol-gel route

Paddy straw (PS) burning is a concerning issue in South Asian countries, clamoring for exploring alternative management strategies. Being a rich source of silica, PS can be a potential nanosilica (SiNPs) source. The current study reports a pioneering approach for green synthesis of high-purity mesoporous SiNPs by sol-gel method using the aqueous extract of Sapindus mukorossi seed pericarp as a stabilizer. The mesoporous nature of SiNPs was harnessed as a carrier for the essential oil to develop the carrier-based formulation. SiNPs were characterized using XRD, EDX, FTIR, FE-SEM, TEM, AFM, DLS, water contact angle, and BET analysis. The synthesized SiNPs possessed a spheroid morphology with an average particle size of 20.34 ± 2.64 nm. XRD results confirmed its amorphous nature. The mesoporous nature of SiNPs was confirmed using BET analysis which showed a cumulative pore volume of 2.059 cm³/g and a high surface area of 746.32 m²/g. The SiNPs were further loaded with clove essential oil (CEO), and the encapsulation of CEO was assessed using UV-Vis, FTIR, and BET analysis. The in-vitro antifungal activity of CEO and CEO-loaded SiNPs (CEO-SiNPs) was evaluated using the agar plate assay. UV-Vis results depicted 62.64% encapsulation of CEO in SiNPs. The antifungal efficacy of CEO-SiNPs against F. oxysporum exhibited minimum inhibitory concentration (MIC), i.e., 125 mg/L, while the MIC of CEO was found to be 250 mg/L. The study delivers new insights into the holistic utilization of PS and propitious contribution toward the circular economy and Sustainable Development Goals (SDGs).

Recent Advances in Nano-Enabled Seed Treatment Strategies for Sustainable Agriculture: Challenges, Risk Assessment, and Future Perspectives

Agro seeds are vulnerable to environmental stressors, adversely affecting seed vigor, crop growth, and crop productivity. Different agrochemical-based seed treatments enhance seed germination, but they can also cause damage to the environment; therefore, sustainable technologies such as nano-based agrochemicals are urgently needed. Nanoagrochemicals can reduce the dose-dependent toxicity of seed treatment, thereby improving seed viability and ensuring the controlled release of nanoagrochemical active ingredients However, the applications of nanoagrochemicals to plants in the field raise concerns about nanomaterial safety, exposure levels, and toxicological implications to the environment and human health. In the present comprehensive review, the development, scope, challenges, and risk assessments of nanoagrochemicals on seed treatment are discussed. Moreover, the implementation obstacles for nanoagrochemicals use in seed treatments, their commercialization potential, and the need for policy regulations to assess possible risks are also discussed. Based on our knowledge, this is the first time that we have presented legendary literature to readers in order to help them gain a deeper understanding of upcoming nanotechnologies that may enable the development of future generation seed treatment agrochemical formulations, their scope, and potential risks associated with seed treatment.

Development of spirotetramat nanoparticles based on mesoporous silica: improving the uptake and translocation of spirotetramat in plants

As an ideal nanocarrier, mesoporous silica nanoparticles (MSNs) have the characteristics of high specific surface area, adjustable pore size, and good biocompatibility, which are excellent carriers for improving the stability and sustained-release performance of pesticides and improving the utilization rate of pesticides In this study, three kinds of particle size MSNs (100 nm, 200 nm, and 400 nm) were prepared by hydrothermal synthesis method, and then, the spirotetramat (Stm) was loaded into MSNs with different particle sizes by solvent volatilization method to prepare Stm nanoparticles with different particle sizes (Stm@MSNs). The results of Stm@MSNs characterization showed that the three particle sizes of MSNs were 112.5, 200.1, and 439.4 nm, respectively. Besides, the pore sizes of the three MSNs were all in the range of 2~50 nm. And the FTIR spectra showed that the Stm was successfully loaded into the channel of MSNs. TGA analysis showed that Stm@MSNs-100, Stm@MSNs-200, and Stm@MSNs-400 had good thermal stability in the range of 200°C. The drug loads of Stm@MSNs-100, Stm@MSNs-200, and Stm@MSNs-400 to Stm were 38%, 21%, and 53%. The release test showed that all of them showed the characteristics of slow release. After 3 days of application on cucumber plants, Stm was detected in both upper and lower leaves of cucumber. Compared with MSNs-200 and MSNs-400, the nanocarrier MSNs-100 were more easily absorbed by cucumber plants and could carry more Stm into cucumber plants. This study provided a theoretical basis for the development and application of nanocarriers and the improvement of pesticide utilization rate by discussing the effects of different particle size MSNs on the slow release and systemicity of pesticides.

Fabrication, Characterization and In Planta Uptake of Engineered Surfactant Nanovesicles for the Delivery of the Biostimulant Sodium Copper Chlorophyllin

Effective delivery of agrochemicals requires control over bioactive release kinetics coupled with effective penetration of the bioactive into plants. Herein, we demonstrate the fabrication of hybrid nanovesicles based on sodium dodecylbenzenesulfonate (SDBS) and cetyltrimethylammonium bromide (CTAB) for enabling effective delivery of the biostimulant sodium copper chlorophyllin (Cu-chl) into plants. SDBS-CTAB nanovesicles exhibited a particle size of 107 nm with a well-defined spherical morphology, while modified formulations that included small fractions of the unsaturated dopant Span 80 yielded larger nanovesicles that were softer and more irregular in shape. All nanovesicles maintained high colloidal stability over >4 weeks and enabled sustained Cu-chl release, with the incorporation of Span 80 into the membranes enabling controllable acceleration of the release rate. Nanovesicle encapsulation improved the photostability of Cu-chl bioactive 3-4 × relative to that of free Cu-chl and enabled significant penetration of Cu-chl into the plant root without inducing any significant phytotoxicity.

A comparative study on the modulatory role of mesoporous silica nanoparticles MCM 41 and MCM 48 on growth and metabolism of dicot Vigna radiata

With the advent of nanoscience, nanotechnology and their applications in various fields, mesoporous silica nanoparticles have gained popularity due to their stability, biocompatibility, unique honeycomb-like structures - ordered and random by nature, large surface to volume ratio, porosity, active surfaces, high loading capacity, ease of interactions with solvent, solute and suspended particles. These multitudes of intrinsic properties have motivated us towards an interdisciplinary detailed study on applications of mesoporous silica with an intention in increasing efficacy of productivity, growth if any, in plant life. This study aims at finding modus operandi of the structural uniqueness and eccentricity of various types of mesoporous silica in maneuvering their own functionality as a potential regulator for growth of seedlings of model plant Vigna radiata. We undertook characterization of surface, morphology, epitome of porosity for MCM 41 and MCM 48 using various experimental techniques followed by application of the same to growing seedlings at various dosages. It turned out that mesoporous silica nanoparticles, inarguably have higher efficacy in promoting plant growth, reducing stress, and enhancing basic metabolic rates at optimum dosage. Optimal operation point was determined at effective dosages for MCM 41 and MCM 48 those are being much lower than that of conventional silica nanoparticles. This optimum dosage is attributed to the structures of the nanoparticles used and implied further that higher pore volume, higher surface to volume ratio in case of MCM 41 at higher dosage lead to better adsorption of ions and functionality in contrast to that of MCM 48.

Improving Insecticidal Activity of Chlorantraniliprole by Replacing the Chloropyridinyl Moiety with a Substituted Cyanophenyl Group

Insect ryanodine receptors (RyRs) are molecular targets of the anthranilic diamide insecticides. In the present study, a new series of anthranilic diamides containing a cyanophenyl pyrazole moiety were rationally designed by active-fragment assembly and computer-aided design using the 3D structure of Plutella xylostella RyRs as a receptor and chlorantraniliprole as a ligand. Most of the titled compounds showed good toxicity against Mythimna separate, P. xylostella, and Spodoptera frugiperda. Compounds CN06, CN11, and CN16 with corresponding LC₅₀ values of 0.15, 0.29, and 0.52 mg·L^-1, respectively, against M. separate showed comparable activity to that of chlorantraniliprole (0.13 mg·L^-1). Surprisingly, CN06, CN11, and CN16 with corresponding LC₅₀ values of 1.6 × 10^-5, 3.0 × 10^-5, and 2.8 × 10^-5 mg·L^-1, respectively, against P. xylostella were at least 5-fold more active than chlorantraniliprole (1.5 × 10^-4 mg·L^-1). In the case of S. frugiperda, CN06, CN11, and CN16 had good potency but lower than chlorantraniliprole in terms of LC₅₀ values (0.58, 0.54, and 0.56 mg·L^-1 versus 0.31 mg·L^-1). Molecular docking of CN06 and chlorantraniliprole to P. xylostella RyRs validated the molecular design, and the calcium imaging technique further proved the potential target of CN06 as RyRs. Compounds CN06, CN11, and CN16 could be more effective than chlorantraniliprole in targeting the resistant RyR mutants of S. frugiperda (G4891E, I4734M) through the binding mode and energy obtained by molecular docking. Density functional theory calculations (DFT) and electrostatic potential (ESP) studies gave the structure-activity relationship. Compounds CN06, CN11, and CN16 could be used as potent insecticide leads for further optimization.

Uptake, translocation and metabolism of imidacloprid loaded within fluorescent mesoporous silica nanoparticles in tomato (Solanum lycopersicum)

Fluorescence-labeling technology has been widely used for rapid detection of pesticides in agricultural production. However, there are few studies on the use of this technology to investigate pesticide uptake and transport in plants with fluorescent nanoparticle formulations. Here, we investigated uptake, transport, accumulation and metabolism of imidacloprid loaded in fluorescent mesoporous SiO₂ nanoparticles (Im@FL-MSNs) in tomato plants, and compared the results with the pesticide application in granular formulation. The results revealed that Im@FL-MSNs applied via root uptake and foliar spray both could effectively transport in tomato plants and carry the imidacloprid to plant tissues. Neither Im@FL-MSNs nor imidacloprid was detected inside of tomato fruits from root uptake or foliar spray applications. Compared with the foliar application of granular formulation, imidacloprid in Im@FL-MSNs demonstrated a higher concentration in leaves (1.14 ± 0.07 mg/kg > 1.08 ± 0.04 mg/kg, 1.13 ± 0.09 mg/kg > 1.11 ± 0.02 mg/kg), longer half-life (0.84 d < 1.31 d, 0.90 d < 1.36 d) and small numbers of metabolites formed. These results suggest that mesoporous silica nanoparticles could serve as an effective and efficient pesticide carrier for achieving the high use efficiency in plant protection. The information is also helpful to guide the pesticide applications and assess the risks associated with environmental quality and dietary consumption of vegetables.

Nano-enabled agrochemicals/materials: Potential human health impact, risk assessment, management strategies and future prospects

Nanotechnology is a rapidly developing technology that will have a significant impact on product development in the next few years. The technology is already being employed in cutting-edge cosmetic and healthcare products. Nanotechnology and nanoparticles have a strong potential for product and process innovation in the food industrial sector. This is already being demonstrated by food product availability made using nanotechnology. Nanotechnologies will have an impact on food security, packaging materials, delivery systems, bioavailability, and new disease detection materials in the food production chain, contributing to the UN Millennium Development Goals targets. Food products using nanoparticles are already gaining traction into the market, with an emphasis on online sales. This means that pre- and post-marketing regulatory frameworks and risk assessments must meet certain standards. There are potential advantages of nanotechnologies for agriculture, consumers and the food industry at large as they are with other new and growing technologies. However, little is understood about the safety implications of applying nanotechnologies to agriculture and incorporating nanoparticles into food. As a result, policymakers and scientists must move quickly, as regulatory systems appear to require change, and scientists should contribute to these adaptations. Their combined efforts should make it easier to reduce health and environmental impacts while also promoting the economic growth of nanotechnologies in the food supply chain. This review highlighted the benefits of a number of nano enabled agrochemicals/materials, the potential health impacts as well as the risk assessment and risk management for nanoparticles in the agriculture and food production chain.

Discovery of Novel Triazolothiadiazines as Fungicidal Leads Targeting Pyruvate Kinase

Pyruvate kinase (PK) was discovered as a potent new target for novel fungicide development. A series of novel triazolothiadiazine derivatives were rationally designed and synthesized by a ring expansion strategy and computer-aided pesticide design using the 3D structure of Rhizoctonia solani PK (RsPK) obtained by homology modeling as a receptor and our previously discovered lead YZK-C22 as a ligand. The in vitro bioassay results indicated that compounds 4g, 6h, 6m, 6n, 6o, and 6p exhibited good activity against R. solani with the EC₅₀ values falling between 10.99 and 72.76 μM. Especially, 6m showed similar potency to YZK-C22 (10.99 vs 11.97 μM of the EC₅₀ value, respectively). The in vivo bioassay results suggested that 6m against R. solani at a concentration of 200 μg/mL displayed a numerically higher inhibition than YZK-C22 (70 vs 60%, respectively). A field experiment validated that 6m at an application rate of 120 g ai/ha showed comparable efficacy against R. solani to thifluzamide at an application rate of 80 g ai/ha (77.80 vs 84.5%, respectively). Enzymatic inhibition suggested that the potency of 6m was about twofold lower than that of YZK-C22 (67.30 vs 32.64 μM of IC₅₀, respectively). Fluorescence quenching studies validated that RsPK was quenched by both 6m and YZK-C22, implying that they both might act at the same target site of PK. A possible binding conformation of 6m in the RsPK active site was depicted by molecular docking. Our studies suggest that 6m could be a fungicidal lead targeting PK.

Preparation of thermosensitive buprofezin-loaded mesoporous silica nanoparticles by the sol-gel method and their application in pest control

BACKGROUND

Environmental stimuli-responsive release is one important way to reduce the dosage of pesticide, increase the usage efficiency and improve environmental compatibility.

RESULTS

On this basis, we synthesized mesoporous silica nanoparticles (MSNs) and modified them to develop a thermosensitive pesticide controlled release formulation (CRF). In this study, MSNs prepared by the sol-gel method were used as the core, poly (N-IsoPropylAcrylaMide) [P (NIPAM-MAA)] was used as the shell, and buprofezin (Bup) was loaded by adsorption. The prepared Bup@MSNs@P(NIPAM-MAA) could effectively prevent the degradation of buprofezin under UV light and exhibited excellent adhesion to rice leaves. The bioassay results showed that the mortality of Nilaparvata lugens (Stål) treated by Bup@MSNs@P(NIPAM-MAA) was positively correlated with temperature, resulting mainly from the change of release amount of buprofezin caused by temperature variation. Bup@MSNs@P(NIPAM-MAA) had long duration (20 days) for controlling N. lugens, and did not hinder the growth of rice. Meanwhile, Bup@MSNs@P(NIPAM-MAA) had low toxicity to zebrafish and human pneumonocyte BEAS-2B cells.

CONCLUSION

This novel thermosensitive pesticide CRF can be applied widely to other insecticides, thus greatly promoting the development of intelligent pesticide formulations. © 2021 Society of Chemical Industry.

Multiple Roles of Mesoporous Silica in Safe Pesticide Application by Nanotechnology: A Review

Pollution related to pesticides has become a global problem due to their low utilization and non-targeting application, and nanotechnology has shown great potential in promoting sustainable agriculture. Nowadays, mesoporous silica-based nanomaterials have garnered immense attention for improving the efficacy and safety of pesticides due to their distinctive advantages of low toxicity, high thermal and chemical stability, and particularly size tunability and versatile functionality. Based on the introduction of the structure and synthesis of different types of mesoporous silica nanoparticles (MSNs), the multiple roles of mesoporous silica in safe pesticide application using nanotechnology are discussed in this Review: (i) as nanocarrier for sustained/controlled delivery of pesticides, (ii) as adsorbent for enrichment or removal of pesticides in aqueous media, (iii) as support of catalysts for degradation of pesticide contaminants, and (iv) as support of sensors for detection of pesticides. Several scientific issues, strategies, and mechanisms regarding the application of MSNs in the pesticide field are presented, with their future directions discussed in terms of their environmental risk assessment, in-depth mechanism exploration, and cost-benefit consideration for their continuous development. This Review will provide critical information to related researchers and may open up their minds to develop new advances in pesticide application.

A Light-Triggered pH-Responsive Metal-Organic Framework for Smart Delivery of Fungicide to Control Sclerotinia Diseases of Oilseed Rape

Using a simple one-pot method, we developed a prochloraz (Pro) and pH-jump reagent-loaded zeolitic imidazolate framework-8 (PD@ZIF-8) composite for the smart control of Sclerotinia disease. The pH-jump reagent can induce the acidic degradation of ZIF-8 using UV light to realize the controlled release of Pro. Thus, the physical properties of PD@ZIF-8, such as its release, formulation stability, and adhesion, were investigated in detail. The results showed that the quantity of Pro released by PD@ZIF-8 under UV light irradiation (365 nm) was 63.4 ± 3.5%, whereas under dark conditions, it was only 13.7 ± 0.8%. In vitro activity indicated that the EC₅₀ of PD@ZIF-8 under UV light irradiation was 0.122 ± 0.02 μg/mL, which was not significantly different from that of Pro (0.107 ± 0.01 μg/mL). Pot experiments showed that the efficacy of PD@ZIF-8 under light irradiation was 51.2 ± 5.7% for a fungal infection at 14 days post-spraying, whereas the effectiveness of prochloraz emulsion in water was only 9.3 ± 3.3%. Furthermore, fluorescence tracking of ZIF-8 and biosafety experiments showed that ZIF-8 could be absorbed by plant leaves and transported to various parts of oilseed rape in a short period of time and that PD@ZIF-8 was relatively safe for plants and HepG2 cells. These results highlight the potential of the composite to provide efficient and smart delivery of fungicides into plants for protection against diseases and provide an idea for developing sustainable agriculture.

Size Effect of Mesoporous Silica Nanoparticles on Pesticide Loading, Release, and Delivery in Cucumber Plants

Mesoporous silica nanoparticles (MSN) are widely used as pesticide carriers to enhance their effective utilization, since it can promote the solubility and absorption of pesticides by plants. For plants, the particle size of pesticides influences their absorption and efficacy. Herein, is our research work of the size effect of MSN on the loading, release, and delivery behavior of pyraoxystrobin (Pyr) in cucumber plants. The well-ordered Pyr-loaded carbon quantum dots-MSN (Pyr@M) with sizes of 15, 100, and 200 nm were prepared. A comparative study among different particle sizes of Pyr@M was carried out on the aspects of control release performance, loading content, uptake, and transportation performance in cucumber plants. It was found that the loading content increased as the particle size increased. The nanoparticles as carriers increased the solubility of insoluble Pyr, but the nanoparticle size had no clear difference impact on the release rate. The efficiency of the cellular uptake strongly depended on the particle size. The smaller the MSN size, the easier it was to be absorbed and transmitted by cucumber plants. Compared to the free Pyr, the upward transportation rate of Pyr from Pyr@M in plant increased by 3.5 times. These findings provide new theoretical basis to design the MSN pesticide delivery system.

Recent advances and remaining barriers to producing novel formulations of fungicides for safe and sustainable agriculture

BACKGROUND

Fungi have evolved for 1 billion years and due to their adaptability and resilience can be found in multiple habitats around the globe. Among numerous species of fungi, some are pathogenic, and humans have battled since the dawn of organized agriculture to reduce production losses. With the arrival of fungicides many gains have been made in this struggle. However, though fungicides have greatly contributed to substantial increase in agricultural productivity, their over usage has led to both health and environmental repercussions. They remain cornerstone of the agriculture industry, however, development of safer formulations to champion sustainable and eco-friendly agriculture is of great importance, especially in face of a growing global population, climate change and increasing fungal resistance to existing compounds.

SCOPE AND APPROACH

The aim of this review is to present the state of the art in fungicides formulations developed for agrochemistry, also describing recent improvements in their safety, with special focus on fungicides used most against the ten most important fungal pathogens.

KEY FINDINGS AND CONCLUSIONS

The major focus in the field remains to be the improvement of the overall performance of the fungicide formulations. The research trends are also moving towards developing more eco-friendly formulations. However, there are still very few studies assessing nanoformulations toxicity and environmental impact. For example, there is still a limited body of research on the holistic assessment of nanoformulation shells' fate in soil and in the environment after release, as well as redistribution within plants after absorption, with no studies on human or environmental exposure.