Journal of Experimental Agriculture International

Conventional pesticide application remains inefficient, with a large share of the applied active ingredient lost to drift, runoff, leaching and degradation before reaching the target organism. Nanotechnology has been proposed as a route to "smart" and more sustainable crop protection through two largely separate lines of research: nano-enabled pesticides that alter the delivery, persistence and release of active ingredients, and nanosensors that detect pesticide residues or early signs of plant stress. This critical narrative review evaluates both lines of evidence together and asks whether the combined claim of greater efficacy, lower environmental burden and data-driven application is supported. Peer-reviewed literature published between January 2000 and July 2026 was identified through structured searches of multidisciplinary and biomedical scholarly indexes, supplemented by citation tracking and institutional sources, and appraised for design, controls, nano-specific characterisation and ecological relevance. The strongest evidence shows that nanoformulations can improve foliar retention, photostability and pest control under laboratory and greenhouse conditions, and that nanosensors can reach very low detection limits in prepared samples. Evidence becomes considerably weaker at field scale. Aggregate efficacy gains are moderate and vary with the comparator chosen, replicated multi-season field trials are scarce, and environmental benefits are inconsistent because nanoformulations may change sorption, degradation, mobility and non-target toxicity in either direction. Sensor studies rarely report inter-laboratory reproducibility, matrix-matched validation or comparison with accepted chromatographic methods, and the specificity of enzyme-inhibition formats is limited. Plant-embedded and wearable sensors are mechanistically promising but have not yet been connected to validated decision rules for pesticide application. Regulatory frameworks, life-cycle accounting and cost evidence remain underdeveloped. The review concludes that nano-enabled crop protection is a credible but conditional technology family whose sustainability benefits depend on design choices, comparators and deployment context rather than on nanoscale properties alone. Priorities include standardised field trials with appropriate commercial comparators, nano-specific fate and ecotoxicity testing, validation of sensors against reference methods in real agricultural matrices, and pilot studies that link sensing to application decisions and measure net reductions in pesticide load.