Acaricidal Activity of Geraniol-Loaded Lignin Nanoparticles for the Control of Brevipalpus Chilensis: An Eco-Friendly Approach to Crop Protection

The environmental pollution and health risks associated with synthetic pesticides have driven increasing interest in plant-derived biopesticides like geraniol. However, their practical application is limited by high volatility and low solubility. In this study, lignin nanoparticles were used as a carrier system to enhance the stability and acaricidal efficacy of geraniol against Brevipalpus chilensis. The nanoprecipitation process enabled the synthesis of spherical geraniol-loaded lignin nanoparticles with an average size of 200 ± 27.2 nm, a surface charge of −29 ± 3.9 mV and an encapsulation efficiency of 46.5%. The release profile of encapsulated geraniol was assessed, and UV exposure assays demonstrated significantly improved stability compared to free geraniol. Bioassays revealed significantly higher mortality rates of Brevipalpus chilensis when treated with geraniol-loaded nanoparticles compared to free geraniol, highlighting the enhanced efficacy of the encapsulated compound. Additionally, nanoparticle formulations exhibited low cytotoxicity in HeLa cells. Overall, this study underscores the potential of lignin nanoparticles as a promising delivery system for optimizing biopesticide formulations in sustainable agriculture. © 2025 The Royal Society of Chemistry.