Nanomaze Lure: Pheromone Sandwich in Graphene Oxide Interlayers for Sustainable Targeted Pest Control

Handheld Crop Pest Sensor Using Binary Catalyst-Loaded Nano-SnO2 Particles for Oxidative Signal Amplification

In agriculture, pest management is a major challenge. Crop releases volatiles in response to the pest; hence, sensing these volatile signals at a very early stage will ease pest management. Here, binary catalyst-loaded SnO2 nanoparticles of <5 nm were synthesized for the repeated capture and oxidation of the signature volatile and its products to amplify the chemoresistive signal to detect concentrations as low as ≈120 ppb. The sensitivity may be due to the presence of the elements in the Sn-Fe-Pt bond evidenced by extended X-ray absorption fine-structure spectroscopy (EXAFS) that captures and oxidize the volatile without escaping. This strong catalyst may oxidize nontarget volatiles and can cause false signals; hence, a molecular sieve filter has been coupled to ensure high selectivity for the detection ofTuta absolutainfestation in tomato. Finally, with the support of a mobile power bank, the optimized sensor has been assembled into a lightweight handheld device.

Nano-Micro Core-Shell Fibers for Efficient Pest Trapping

Insect sex pheromones as an alternative to chemical pesticides hold promising prospects in pest control. However, their burst release and duration need to be optimized. Herein, pheromone-loaded core-shell fibers composed of degradable polycaprolactone and polyhydroxybutyrate were prepared by coaxial electrospinning. The results showed that this core-shell fiber had good hydrophobic performance and thermal stability, and the light transmittance in the ultraviolet band was only below 40%, which provided protection to pheromones. The core-shell structure alleviated the burst release of pheromone in the fiber and extended the release time to about 133 days. In the field, the pheromone-loaded core-shell fibers showed the same continuous and efficient trapping of Spodoptera litura as the commercial carriers. More importantly, the electrospun fibers combined with biomaterials had a degradability unmatched by commercial carriers. The structure design strategy provides ideas for the innovative design of pheromone carriers and is a potential tool for the management of agricultural pests.

Bioactivity, Uptake, and Distribution of Prothioconazole Loaded on Fluorescent Double-Hollow Shelled Mesoporous Silica in Soybean Plants

Prothioconazole (PTC) has been widely utilized for plant fungal disease control, but its metabolite prothioconazole-desthio (PTC-d) exhibits reproductive toxicity. In the present study, carbon quantum dot (CQD)-modified fluorescent double-hollow shelled mesoporous silica nanoparticles (FL-MSNs) loaded with PTC, referred to as PTC@FL-MSNs, were constructed with an average size of 369 nm and a loading capacity of 28.1 wt %, which could increase the antifungal efficiency of PTC. In addition, upright fluorescence microscope and UPLC-MS/MS studies showed that PTC@FL-MSNs could be effectively transported via root uptake and foliar spray in soybean plants. Compared to a 30% PTC dispersible oil suspension agent, the PTC@FL-MSN treatment group showed higher concentrations (leaves: 0.50 > 0.48 mg/kg), longer half-lives for degradation (leaves: 3.62 > 3.21 d; roots: 3.39 > 2.82 d), and fewer metabolites. These findings suggest that sustained pesticide release and toxicity reduction are potential applications for PTC nanofungicide delivery technology.

Biosynthesis and characterization of nanoparticles, its advantages, various aspects and risk assessment to maintain the sustainable agriculture: Emerging technology in modern era science

The current review aims to gain knowledge on the biosynthesis and characterization of nanoparticles (NPs), their multifactorial role, and emerging trends of NPs utilization in modern science, particularly in sustainable agriculture, for increased yield to solve the food problem in the coming era. However, it is well known that an environment-friendly resource is in excessive demand, and green chemistry is an advanced and rising resource in exploring eco-friendly processes. Plant extracts or other resources can be utilized to synthesize different types of NPS. Hence NPs can be synthesized by organic or inorganic molecules. Inorganic molecules are hydrophilic, biocompatible, and highly steady compared to organic types. NPs occur in numerous chemical conformations ranging from amphiphilic molecules to metal oxides, from artificial polymers to bulky biomolecules. NPs structures can be examined by different approaches, i.e., Raman spectroscopy, optical spectroscopy, X-ray fluorescence, and solid-state NMR. Nano-agrochemical is a unification of nanotechnology and agro-chemicals, which has brought about the manufacture of nano-fertilizers, nano-pesticides, nano-herbicides, nano-insecticides, and nano-fungicides. NPs can also be utilized as an antimicrobial solution, but the mode of action for antibacterial NPs is poorly understood. Presently known mechanisms comprise the induction of oxidative stress, the release of metal ions, and non-oxidative stress. Multiple modes of action towards microbes would be needed in a similar bacterial cell for antibacterial resistance to develop. Finally, we visualize multidisciplinary cooperative methods will be essential to fill the information gap in nano-agrochemicals and drive toward the usage of green NPs in agriculture and plant science study.

Valorisation of fruit peel bioactive into green synthesized silver nanoparticles to modify cellulose wrapper for shelf-life extension of packaged bread

Fruit peels are rich source of bioactive compounds such as polyphenols, flavonoids, and antioxidants but are often discarded as waste due to limited pharmaceutical and nutraceutical applications. This study aimed to valorise pomegranate and citrus fruit peel into green synthesised silver nanoparticles (AgNPs) in order to modify cellulose-based wrapping material for prospective food packaging applications and propose an alternate and sustainable approach to replace polyethene based food packaging material. Four different concentrations of AgNO₃ (0.5 mM, 1 mM, 2 mM, and 3 mM) were used for green synthesis of AgNPs from fruit peel bioactive, which were characterised followed by phytochemical analysis. Ultraviolet-Visible spectroscopy showed surface plasmon resonance at 420 nm, XRD analysis showed 2θ peak at 27.8°, 32.16°, 38.5°, 44.31°, 46.09°, 54.76°, 57.47°, 64.61° and 77.50° corresponding to (210), (122), (111), (200), (231), (142), (241), (220) and (311) plane of face centred cubic crystal structure of AgNPs. Fourier-transform infrared spectroscopy analysis of AgNPs green synthesised from pomegranate and kinnow peel extract showed a major peak at 3277, 1640 and 1250-1020 1/cm while a small peak at 2786 1/cm was observed in case of pomegranate peel extract which was negligible in AgNPs synthesized from kinnow peel extract. Particle sizes of AgNPs showed no statistically significant variance with p > 0.10 and thus, 2 mM was chosen for further experimentation and modification of cellulose based packaging material as it showed smallest average particle size. Zeta potential was observed to be nearly neutral with a partial negative strength due to presence of various phenolic compounds such as presence of gallic acid which was confirmed by ultrahigh performance liquid chromatography-photodiode array(UHPLC-PDA) detector. Thermal stability analysis of green synthesised AgNPs qualified the sterilisation conditions up to 100 °C. AgNPs green synthesized from both the peel extracts had higher polyphenolic content, antioxidant and radical scavenging activity as compared to peel extracts without treatment (p < 0.05). The cellulose based food grade packaging material was enrobed by green synthesised AgNPs. The characterisation of modified cellulose wrappers showed no significant difference in thickness of modified cellulose wrappers as compared with untreated cellulose wrapper (p > 0.42) while weight and grammage increased significantly in modified cellulose wrapper (p < 0.05). The colour values on CIE scale (L*, a* and b*) showed statistically significant increase in yellow and green colour (p < 0.05) for modified cellulose wrappers as compared to control wrapper. The oxygen permeability coefficient, water vapour permeability coefficient, water absorption capacity and water behaviour characteristics (water content, swelling degree and solubility) showed significant decrease (p < 0.05) for modified cellulose wrapper as compared to control wrapper. A uniform distribution and density of green synthesised AgNPs across cellulose wrapper matrix was observed through scanning electron microscopy (SEM) images with no significant aggregation, confirming successful enrobing and stable immobilisation of nanoparticles from cellulose matrix. A seven-day storage study of bread wrapped in modified and control cellulose wrappers showed delayed occurrence of microbial, yeast and mould count in bread packaged in modified cellulose wrappers and thus, resulting in shelf life extension of bread. The results are encouraging for the potential applications of modified cellulose wrappers to replace polyethene based food packaging.

Advances in stimuli-responsive systems for pesticides delivery: Recent efforts and future outlook

Effective pest management for enhanced crop output is one of the primary goals of establishing sustainable agricultural practices in the world. Pesticides are critical in preventing biological disasters, ensuring crop productivity, and fostering sustainable agricultural production growth. Studies showed that crops are unable to properly utilize pesticides because of several limiting factors, such as leaching and bioconversion, thereby damaging ecosystems and human health. In recent years, stimuli-responsive systems for pesticides delivery (SRSP) by nanotechnology demonstrated excellent promise in enhancing the effectiveness and safety of pesticides. SRSP are being developed with the goal of delivering precise amounts of active substances in response to biological needs and environmental factors. An in-depth analysis of carrier materials, design fundamentals, and classification of SRSP were provided. The adhesion of SRSP to crop tissue, absorption, translocation in and within plants, mobility in the soil, and toxicity were also discussed. The problems and shortcomings that need be resolved to accelerate the actual deployment of SRSP were highlighted in this review.

A Comprehensive Overview of Nanotechnology in Sustainable Agriculture

Plant nutrition is crucial in crop productivity and providing food security to the ever-expanding population. Application of chemical/biological fertilizers and pesticides are the mainstays for any agricultural economy. However, there are unintended consequences of using chemical fertilizers and pesticides. The environment and ecological balance are adversely affected by their usage. Biofertilizers and biopesticides counter some undesired environmental effects of chemical fertilizers/pesticides; inspite of some drawbacks associated with their use. The recent developments in nanotechnology offer promise towards sustainable agriculture. Sustainable agriculture involves addressing the concerns about agriculture as well as of the environment. This review briefs about important nanomaterials used in agriculture as nanofertilizers, nanopesticides, and a combination called nanobiofertilizers. Both nanofertilizers and nanopesticides enable slow and sustained release besides their eco-friendly environmental consequences. They can be tailored to specific needs to crop. Nanofertilizers also offer greater stress tolerance and, therefore, of considerable value in the era of climate change. Furthermore, nanofertilizers/nanopesticides are applied in minute amounts, reducing transportation costs associated and thus positively affecting the economy. Their uses extend beyond such as if nanoparticles (NPs) are used at high concentrations; they affect plant pathogens adversely. Polymer-based biodegradable nanofertilizers and nanopesticides offer various benefits. There is also a dark side to the use of nanomaterials in agriculture. Nanotechnology often involves the use of metal/metal oxide nanoparticles, which might get access to human bodies leading to their accumulation through bio-magnification. Although their effects on human health are not known, NPs may reach toxic concentrations in soil and runoff into rivers, and other water bodies with their removal to become a huge economic burden. Nevertheless, a risk-benefit analysis of nanoformulations must be ensured before their application in sustainable agriculture.

Advances in Biologically Applicable Graphene-Based 2D Nanomaterials

Climate change and increasing contamination of the environment, due to anthropogenic activities, are accompanied with a growing negative impact on human life. Nowadays, humanity is threatened by the increasing incidence of difficult-to-treat cancer and various infectious diseases caused by resistant pathogens, but, on the other hand, ensuring sufficient safe food for balanced human nutrition is threatened by a growing infestation of agriculturally important plants, by various pathogens or by the deteriorating condition of agricultural land. One way to deal with all these undesirable facts is to try to develop technologies and sophisticated materials that could help overcome these negative effects/gloomy prospects. One possibility is to try to use nanotechnology and, within this broad field, to focus also on the study of two-dimensional carbon-based nanomaterials, which have excellent prospects to be used in various economic sectors. In this brief up-to-date overview, attention is paid to recent applications of graphene-based nanomaterials, i.e., graphene, graphene quantum dots, graphene oxide, graphene oxide quantum dots, and reduced graphene oxide. These materials and their various modifications and combinations with other compounds are discussed, regarding their biomedical and agro-ecological applications, i.e., as materials investigated for their antineoplastic and anti-invasive effects, for their effects against various plant pathogens, and as carriers of bioactive agents (drugs, pesticides, fertilizers) as well as materials suitable to be used in theranostics. The negative effects of graphene-based nanomaterials on living organisms, including their mode of action, are analyzed as well.