Sustainable plant mediated synthesis of cobalt oxide nanoparticles using Uraria picta extract with enhanced biological activity

The present study demonstrates a sustainable phytogenic route for the synthesis of cobalt oxide nanoparticles (CoO NPs) utilizing Uraria picta (Jacq.) DC. plant extract as a natural reducing and stabilizing agent. The whole plant was collected, shade-dried, powdered, and processed to obtain an aqueous extract, which was subsequently reacted with cobalt chloride hexahydrate stock solution, leading to the formation of CoO NPs via a green synthesis pathway. The appearance of a distinct color change confirmed nanoparticle formation. The resulting material was centrifuged, filtered, dried, and calcined to obtain blackish-violet CoO NPs. Comprehensive characterization of the biosynthesized nanoparticles was performed using UV-Vis spectroscopy, FTIR, XRD, EDS, SEM, and TEM analyses, confirming their structural, morphological, and elemental properties. Furthermore, the synthesized CoO NPs exhibited significant antioxidant potential and antibacterial activity against selected bacterial strains. This eco-friendly and cost-effective green synthesis approach not only avoids hazardous chemicals but also provides a promising strategy for the development of nanomaterials with potential biological and environmental applications.