A comprehensive review of bio-engineered nanofertilizers, nanopesticides, and nanobiochar for sustainable agriculture: Green synthesis, recent advances, challenges, and future outlooks

With the advancement of nanotechnologies, nano-engineering has emerged as a pivotal strategy for designing bioinspired nanoparticles (NPs) for applications across multifarious sectors, including agriculture, biomedicine, and energy. In sustainable agriculture, escalating climate pressures and the proliferation of pesticide-resistant pests necessitate more precise and environmentally compatible interventions. Bioinspired NPs synthesized from plants, microorganisms, and agro-industrial bio-waste offer a scalable, eco-friendly, and sustainable platform for next-generation agrochemicals to combat pests and enhance agricultural efficiency and sustainability. Bionanofertilizers enhance nutrient use efficiency through controlled release, improved bioavailability, and reduced leaching losses; however, uncertainties persist concerning long-term soil accumulation. Importantly, the emergence of chemically resistant pests to conventional pesticides necessitates a targeted, effective strategy to mitigate their deleterious effects. Bionanopesticides provide targeted delivery, increased stability of active ingredients, and reduced application rates, managing resistance development and off-target effects. Nonetheless, their environmental fate and unintended impacts on non-target organisms remain insufficiently characterized. Additionally, nanobiochar improves nutrient retention, carbon sequestration, and microbial activity; however, its nanoscale reactivity and mobility require further consideration. This review outlines recent advances in bioinspired NPs for agricultural applications, with particular emphasis on mechanistic interactions at the nanoscale, including uptake, translocation, and biotransformation in plant soil systems. Furthermore, we comprehensively discuss current evidence on efficacy with emerging risks, highlighting knowledge gaps in long-term environmental safety, lifecycle assessment, and large-scale deployment. Bridging these gaps is essential to enable biogenic NPs as agricultural inputs to transition from promising innovations into reliable and safe solutions for sustainable food production.