Harnessing plant extracts for green nanoparticle synthesis: Toward a sustainable future

Nanotechnology is revolutionizing diverse scientific fields, yet conventional nanoparticle (NP) synthesis remains energy-intensive and environmentally hazardous. This has fuelled a shift toward sustainable, biogenic approaches, with plant-mediated NP synthesis emerging as a promising alternative. Leveraging the rich diversity of plant-derived phytochemicals, such as flavonoids, polyphenols, and alkaloids, this method offers a sustainable, cost-effective and eco-friendly route to nanoparticle production. However, despite its potential, key challenges remain: the incomplete characterization of plant extracts hampers reproducibility, control over NP morphology, and large-scale implementation. While many studies report successful NP synthesis, a precise understanding of the specialized metabolites involved is still lacking. Bridging this knowledge gap is crucial for optimizing NP properties and expanding their biomedical, catalytic, and industrial applications. This review critically examines the role of specialized plant metabolites in NP synthesis, detailing analytical techniques, such as LC-MS, FTIR, and NMR, for their characterization. Scalability remains a key challenge in plant-mediated nanoparticle synthesis, with reproducibility often limited by non-standardized extraction methods. Strategies such as protocol harmonization, the integration of advanced analytical tools, and the application of artificial intelligence (AI) can significantly enhance consistency and predictability. Recent publication trends show growing interest in green synthesis, particularly in applications across healthcare, food nanotechnology, and smart packaging. Addressing current limitations and deepening the understanding of plant-derived metabolites could shift the field from empirical trials to a standardized, scalable, and industrially viable green technology, supporting the development of sustainable materials. • Green synthesis strategies of plant-based nanoparticles are critically reviewed. • Phytochemical roles and mechanisms in nanoparticle synthesis are explored. • Analytical methods for characterizing green nanoparticles are summarized. • Applications of plant-synthesized nanoparticles are briefly highlighted. • Scalable, sustainable nanoformulations from plants are proposed.