Nanotechnology-enabled Biopesticides: Advanced Formulation Strategies, Target-Specific Delivery Mechanisms, and Translational Challenges in Sustainable Crop Protection

Abstract

Global food security faces mounting pressure from crop-destroying pests and the deeply entrenched reliance on synthetic chemical pesticides that, despite decades of use, are generating accelerating resistance across major pest taxa, widespread ecotoxicological harm to non-target organisms including pollinators and soil biota, and tightening regulatory restrictions in key agricultural markets. Biopesticides — encompassing microbial agents, botanically derived compounds, and semiochemicals — offer a fundamentally more targeted and biodegradable alternative; yet their widespread field adoption has been constrained by rapid photodegradation under UV exposure, thermal instability, shortened residual activity, inconsistent performance under variable seasonal and edaphic conditions, and persistent challenges in formulation shelf life and manufacturing consistency. The integration of engineered nanoscale delivery platforms with biologically active ingredients offers a transformative strategy to overcome these barriers simultaneously. By encapsulating or functionalising biopesticide compounds within purpose-built nanocarriers, it becomes possible to shield active ingredients from premature environmental degradation, programme controlled and stimulus-responsive release profiles, enhance foliar retention and cuticular penetration, and achieve target-specific delivery while minimising off-target exposure to beneficial organisms. This review provides a systematic and critical assessment of nanotechnology-enabled biopesticide development, with three explicit objectives: (i) to evaluate the principal nanoformulation platforms — including biodegradable polymeric nanoparticles, nanoemulsions, solid lipid carriers, inorganic layered double hydroxides, and RNAi-based nanoformulations — in terms of their physicochemical mechanisms, efficacy evidence, and comparative limitations; (ii) to critically analyse the environmental fate, ecotoxicological risks, and resistance management implications of these delivery systems under realistic field conditions; and (iii) to identify the translational barriers — regulatory, economic, and socio-technical — that currently impede the scaling and deployment of nano-biopesticides in diverse agricultural contexts. Environmental fate of nanocarriers in soil and aquatic compartments, effects on non-target microbial communities, and regulatory approval pathways across major jurisdictions are critically assessed. Current limitations of the field — including inadequate long-term ecotoxicological data, the absence of harmonised nano-specific risk frameworks, high production costs, and limited farmer-level evidence — are explicitly identified. Realising the transformative promise of nano-biopesticides will require coordinated advances in regulatory science, cost-competitive manufacturing, multi-season field validation, and inclusive science-policy dialogue with farming communities and development organisations.