River sand derived silica nanoparticles as a sustainable nano-insecticide for stored-product pest control: Characterization, efficacy, mechanism, and seed safety

Stored-product insects cause substantial losses to seeds during storage, necessitating alternatives to conventional synthetic pesticides that pose environmental and resistance challenges. The study explores a green synthesis route using river sand-derived silica nanoparticles (SiO 2 NPs) for the management of Sitophilus oryzae , Callosobruchus maculatus , and Lasioderma serricorne , while evaluating insecticidal efficiency and seed safety. SiO 2 NPs were synthesized and characterized using UV–vis spectroscopy, XRD, FTIR, zeta potential analysis, HR-TEM, FE-SEM, and EDAX. In silico docking assessed interactions with detoxification and neural enzymes, complemented by in vivo insect bioassays, biochemical validation, and seed physiological studies across maize, green gram, and coriander. The NPs exhibited a UV–vis peak at 232 nm with a 5.11 eV band gap, spherical morphology of 33–35 nm, an amorphous structure, a silica-dominant composition, and strong colloidal stability. In silico analysis revealed binding to glutathione S-transferase and mixed-function oxidases, corroborated by biochemical assays. Bioassays showed dose- and time-dependent mortality, with LD 50 /LD 90 values of 1.70/11.48 ( S. oryzae ), 0.60/9.12 ( C. maculatus ), and 1.97/13.94 mg/100 g seeds ( L. serricorne ), primarily via a physical mode of action. Seed treatments enhanced germination and agro-morphological traits while maintaining regulated antioxidant activity, confirming physiological compatibility. Silicon accumulation further validated effective uptake. Collectively, river sand-derived SiO₂ NPs act as a dual-function system integrating insect suppression with seed performance enhancement, offering a scalable, eco-compatible strategy for stored-seed protection, with potential for field-scale application and nutrient-engineered NP optimization. • SiO₂ NPs showed a UV–vis peak at 232 nm with a direct band gap of 5.11 eV. • Characterization confirmed amorphous, negatively charged, spherical SiO₂ NPs (33–35 nm) with a silica-dominant composition. • In silico analysis revealed stable binding to key detoxification and neural enzymes of S. oryzae , C. maculatus , and L. serricorne . • Bioassays indicated dose- and time-dependent toxicity with low LD₅₀/LD₉₀ values via physical action and biochemical modulation. • Seed treatment enhanced growth traits, antioxidant balance, and silicon accumulation in maize, green gram, and coriander.