<i>Salvia abrotanoides</i> methanolic extract Fe ₃ O ₄ @Carbon nanocomposite as biological approach for protection against the <i>Potato Tuber</i> Moth

Plant-based nano-insecticides like <i>Salvia abrotanoides</i> provide eco-friendly pest control with low resistance risk. This study aimed to evaluate the insecticidal activity of the Fe₃O₄ @Carbon nanoformulation of <i>S. abrotanoides</i> extract with a carbon shell and pure extract against <i>Phthorimaea operculella</i> (eggs and larvae), a significant potato pest in Iran. A modified solvothermal method produced highly water-dispersible magnetite (Fe₃O₄) particles, with citrate as a stabilising agent. A carbon layer was added through hydrothermal treatment, using polyethylene glycol as a linking agent between glucose and the Fe₃O₄ spheres. SEM analysis confirmed the structure of the Fe₃O₄@Carbon nanocomposite, while FTIR and EDS verified the methanolic extract's presence. The Fe₃O₄@Carbon nano extract demonstrated greater toxicity to the pest's eggs and larvae than the pure extract, with lower LC₅₀ values (752.23-355 ppm), indicating higher potency. These findings confirm that Fe₃O₄@Carbon <i>S. abrotanoides</i> nanoparticles are effective, pollution-free, and green nano-insecticides against <i>Ph. operculella</i>.