Phytogenic synthesized selected metal oxides, properties, and biotechnological applications

Plant extract-assisted green synthesis has emerged as a sustainable and reliable alternative to conventional chemical routes for fabricating metal oxides. Phytochemicals such as proteins, amino acids, vitamins, polysaccharides, and organic acids play key roles as reducing, stabilizing, and capping agents, which enable controlled formation of metal oxide nanostructures with enhanced biocompatibility. This review summarizes recent advances in the use of diverse plant extracts for synthesizing selected metal oxides and highlights how variations in extract composition and reaction parameters influence morphological, optical, and functional properties. Key mechanistic insights into the role of phytochemicals are discussed, along with factors affecting reproducibility and scalability. Furthermore, the review outlines emerging biotechnological and biomedical applications where green-synthesized metal oxides show significant promise. By strengthening current progress and identifying critical knowledge gaps, this work provides a foundation for developing more predictable, tunable, and application-specific phytogenic synthesis strategies.