Phytochemical analysis and fabrication of silver nanoparticles using Acacia catechu: An efficacious and ecofriendly control tool against selected polyphagous insect pests

Emerging trends to replace pesticides with nanomaterials: Recent experiences and future perspectives for ecofriendly environment

Despite the widespread usage to safeguard crops and manage pests, pesticides have detrimental effects on the environment and human health. The necessity to find sustainable agricultural techniques and meet the growing demand for food production has spurred the quest for pesticide substitutes other than traditional ones. The unique qualities of nanotechnology, including its high surface area-to-volume ratio, controlled release, and better stability, have made it a promising choice for pest management. Over the past ten years, there has been a noticeable growth in the usage of nanomaterials for pest management; however, concerns about their possible effects on the environment and human health have also surfaced. The purpose of this review paper is to give a broad overview of the worldwide trends and environmental effects of using nanomaterials in place of pesticides. The various types of nanomaterials, their characteristics, and their possible application in crop protection are covered. The limits of the current regulatory frameworks for nanomaterials in agriculture are further highlighted in this review. Additionally, it describes how standard testing procedures must be followed to assess the effects of nanomaterials on the environment and human health before their commercialization. In order to establish sustainable and secure nanotechnology-based pest control techniques, the review concludes by highlighting the significance of taking into account the possible hazards and benefits of nanomaterials for pest management and the necessity of an integrated approach. It also emphasizes the importance of more investigation into the behavior and environmental fate of nanomaterials to guarantee their safe and efficient application in agriculture.

Eco-friendly approaches of zinc oxide and silver nitrate nanoparticles along with plant extracts against Spodoptera litura (Fabricius) under laboratory conditions

The tobacco cutworm (Spodoptera litura) is a widespread pest that inflicts severe damage on various crops, including cotton, tobacco, and vegetables, with a particular preference for solanaceous plants. Traditional control methods often rely heavily on synthetic insecticides, leading to adverse effects on the environment, human health, and the development of insecticide resistance. In light of these challenges, this study explores the potential of nanotechnology as an innovative and sustainable approach to combat this notorious pest. Bioassays were conducted using laboratory-reared 3rd instar S. litura larvae. Eight different plant extracts coated with zinc oxide and silver nitrate nanoparticles were tested, with concentrations in both distilled water and ethanol at 3, 5, and 7 ml. Data were collected at 24, 48, and 72-h intervals. The results revealed that the highest larval mortality, reaching 98%, was observed in the group treated with silver nitrate nanoparticles derived from Cymbopogon citratus. In comparison, the group treated with zinc oxide nanoparticles dissolved in ethanol exhibited a larval mortality rate of 90%. Ethanol is a polar solvent that is widely used in the synthesis of nanocomposites. It is capable of forming strong hydrogen bonds with oxygen atoms, making it a good dispersant for zinc oxide nanoparticles. Additionally, ethanol has a low boiling point and a non-toxic nature, which makes it a safe and effective option for the dispersion of nanoparticles. Notably, the study concluded that silver nanoparticles combined with ethanol exhibited prolonged and more potent toxic effects against S. litura when compared to zinc oxide nanoparticles. Overall, this research underscores the potential of nanotechnology as a valuable component of Integrated Pest Management (IPM) strategies. By integrating nanotechnology into pest management practices, we can promote sustainable and environmentally friendly approaches that benefit both farmers and the ecosystem.

In vitro and in silico studies of silver nanoparticles (AgNPs) from Allium sativum against diabetes

In the present study, the silver nanoparticles (AgNPs) were synthesized from the bulbs of Allium sativum, characterized by UV-visible spectroscopy, FT-IR, SEM, HR-TEM, EDAX analysis and investigated its action on the inhibition of starch digestion. The results proved that the biosynthesized nanoparticles were uniformly dispersed, spherical shaped with the size ranging from 10 to 30 nm. The phytochemical and FT-IR analysis showed the presence of phenols, terpenoids, and amino acids in the synthesized AgNPs. The cytotoxicity analysis revealed that the synthesized AgNPs were non-toxic to the normal cells. The synthesized AgNPs exhibited significant free radical scavenging activity. The in vitro antidiabetic activity showed that the synthesized AgNPs increased glucose utilization, decreased hepatic glucose production, inhibited the activity of starch digestive enzymes such as α-amylase and α-glucosidase, and were not involved in the stimulation of pancreatic cells for the secretion of insulin. The in silico antidiabetic activity analysis (molecular docking) also revealed that the silver atoms of the AgNPs interacted with the amino acid residues of α-amylase, α-glucosidase, and insulin. The present study proved that the AgNPs synthesized from A. sativum have prominent antidiabetic activity in terms of reducing the hyperglycemia through the increased glucose utilization, decreased hepatic glucose production, and the inhibition of α-amylase and α-glucosidase enzymes. So it can be used as a promising nanomedicine for the treatment of diabetes.

Synthesis, Characterization, Antibacterial, Antifungal, Antioxidant, and Anticancer Activities of Nickel-Doped Hydroxyapatite Nanoparticles

The purpose of this research was to investigate the possible antibacterial, antifungal, antioxidant, and anticancer effects of nickel (Ni2+)-doped hydroxyapatite (HAp) nanoparticles (NPs) synthesized using the sol–gel approach. X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy (Raman), field-emission scanning electron microscopy (FESEM), and elemental analysis were used to characterize the Ni2+-doped HApNPs. X-ray diffraction investigation showed that the nanoscale structure of Ni2+-doped HApNPs was hexagonal, with an average crystallite size of 39.91 nm. Ni2+-doped HApNPs were found to be almost spherical in form and 40–50 nm in size, as determined by FESEM analysis. According to EDAX, the atomic percentages of Ca, O, P, and Ni were 20.93, 65.21, 13.32, and 0.55, respectively. Ni2+-doped HApNPs exhibited substantial antibacterial properties when tested in vitro against several pathogens, including Escherichia coli, Shigella flexneri, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Staphylococcus aureus. Antibacterial activity, at 50 mg tested concentration, demonstrated superior effects on G-ve bacteria than G+ve pathogens. The antifungal activity of Oidium caricae, Aspergillus flavus, and A. niger revealed a zone of inhibition of 23, 11, and 5 mm, respectively. These actions rely on the organism’s cell wall structure, size, and shape. Incorporating Ni2+ into HApNPs allows them to function as powerful antioxidants. Ni2+-doped HApNPs had a good cytotoxic impact against the HeLa cell line, which improved with increasing concentration and was detected at a 68.81 µg/mL dosage. According to the findings of this study, the Ni2+-doped HApNPs are extremely promising biologically active candidates owing to their improved functional features.

Synthesis and characterization of TiO2 NPs by aqueous leaf extract of Coleus aromaticus and assess their antibacterial, larvicidal, and anticancer potential

The frequent applications of synthetic chemical insecticides and drugs create resistance among insects and microbes, creating a new threat to human and environmental welfare. This investigation focused on evaluating the possibilities of fabricating and characterizing the titanium dioxide nanoparticles (TiO₂ NPs) from titanium dioxide (TiO₂) through the aqueous leaf extract of Coleus aromaticus. Their biological applications were studied against the larvae of Aedes aegypti human pathogenic bacteria, and cancer cell line. The results revealed that the aqueous leaf extract had the metal reducing proficiency to produce nanoparticles from TiO₂. The synthesized TiO₂ NPs were initially confirmed by visible color changes and Ultraviolet-Visible Spectrophotometer analysis that showed a predominant peak at 332 nm. Furthermore, the nanocrystals, structural alignment, functional groups and elemental compositions were studied by following standard operating protocol in XRD (X-ray Powder Diffraction), FTIR (Fourier Transform Infrared Spectroscopy), TEM (Transmission Electron Microscopy), and EDX (Energy-Dispersive X-ray Spectroscopy) techniques, respectively. The results attained from these techniques confirmed that the plant mediated and fabricated particles were in the nanoscale range (12-33 nm) with a hexagonal shape. The synthesized TiO₂ NPs had an outstanding (1000 μg mL^-1) larvicidal activity against the four stages of instars larvae of Ae. aegypti at 1000 μg mL^-1. It also had an excellent antibacterial potential against E. faecalis (33 mm), followed by S. boydii (30 mm) at 30 mg L^-1 concentration. The green fabricated TiO₂ NPs had a fabulous (92.37%) cytotoxic activity on the HeLa cell line at 100 μg mL^-1 dosage within one day of exposure. The entire results concluded that the C. aromaticus mediated TiO₂ NPs have excellent biological applications and thus, could be considered for the welfare of human beings.

Biosynthesis of Silver Nanoparticles Mediated by Entomopathogenic Fungi: Antimicrobial Resistance, Nanopesticides, and Toxicity

Silver nanoparticles are widely used in the biomedical and agri-food fields due to their versatility. The use of biological methods for the synthesis of silver nanoparticles has increased considerably due to their feasibility and high biocompatibility. In general, microorganisms have been widely explored for the production of silver nanoparticles for several applications. The objective of this work was to evaluate the use of entomopathogenic fungi for the biological synthesis of silver nanoparticles, in comparison to the use of other filamentous fungi, and the possibility of using these nanoparticles as antimicrobial agents and for the control of insect pests. In addition, the in vitro methods commonly used to assess the toxicity of these materials are discussed. Several species of filamentous fungi are known to have the ability to form silver nanoparticles, but few studies have been conducted on the potential of entomopathogenic fungi to produce these materials. The investigation of the toxicity of silver nanoparticles is usually carried out in vitro through cytotoxicity/genotoxicity analyses, using well-established methodologies, such as MTT and comet assays, respectively. The use of silver nanoparticles obtained through entomopathogenic fungi against insects is mainly focused on mosquitoes that transmit diseases to humans, with satisfactory results regarding mortality estimates. Entomopathogenic fungi can be employed in the synthesis of silver nanoparticles for potential use in insect control, but there is a need to expand studies on toxicity so to enable their use also in insect control in agriculture.