Phytochemical-mediated production of Nd ₂ O ₃ nanoparticles using <i>Indigofera tinctoria</i> and their biochemical properties

Green synthesis has gained significant attention as an environmentally benign approach due to its ability to minimize waste, byproducts, and pollution, and utilize nontoxic solvents. This method employs biomass-derived reducing agents for metal salts, where phytochemicals act as in-situ reducing and capping agents, stabilizing the synthesized nanoparticles. Such biomolecules not only prevent nanoparticle agglomeration and lower toxicity but also enhance antibacterial activity, often resulting in synergistic effects. In this study, eco-friendly synthesis of neodymium oxide (Nd2O3) nanoparticles using Indigofera tinctoria leaf extract as a natural reducing and stabilizing agent is presented. This phytochemical-mediated route offers a sustainable alternative to conventional chemical synthesis methods and demonstrates potential for green-nanomaterial production. The biosynthesized Nd2O3 nanoparticles were characterized using FTIR spectroscopy to identify functional groups, XRD analysis to determine crystal structure and phase purity, and FESEM coupled with EDX analysis to examine surface morphology and elemental composition. Antibacterial activity was evaluated against four bacterial strains, revealing notable bactericidal properties. The nanoparticles exhibited moderate inhibition against Gram-positive bacteria (Staphylococcus aureus and Bacillus subtilis) and stronger activity against Gram-negative bacteria (Escherichia coli and Klebsiella pneumoniae). The antibacterial mechanism may involve cell-wall disruption, reactive oxygen species generation, or interference with intracellular components. Antioxidant scavenging activity increased significantly with concentration.