Synthesis of nanoparticles of transition metals by using medicinal plants has been outstreched in recent years because of the characteristic features which are embodied in the end product. This work is proceded with the aim to synthesize and optimize copper nanoparticles (CuNPs-Pl) using aqueous extract of Polyalthia longifolia leaves (PlL) for characterization and evaluation of antimicrobial and antioxidant potential. The synthesis of CuNPs-Pl was confirmed by visual inspection of the dark brown residues in the reaction flask and via absorption band around 580nm by UV/Visible spectroscopy. Synthesis process was optimized through investigation of environmental variables. FTIR analysis was carried out for both PIL and CuNPs-Pl which identified the presence of alkanes, alcoholic, and aldehydic groups in the PlL and their encapsulation on the copper surface. The synthesized CuNPs-Pl were found to be spherical and rod shaped, and polydispersed when investigated through SEM study. Similarly, these nanoparticles had monoclinic structure and crystalline nature when analyzed by XRD. Moreover, these nanoparticles showed metallic form when EDX examination was done. Further, biological activities were performed. The synthesized nanoparticles showed considerable inhibition zones against Escherichia coli (12mm), Bacillus subtilis (11mm), Aspergillus niger (10mm), and Schyzophyllum commune (16mm) which depicted their powerful antibacterial and antifungal activity. Likewise, CuNPs-Pl were effeciently able to quench free radicals as indicated from the 2, 2-diphenyl-1-picrylhydrazyl (DPPH), hydrogen peroxide (H2O2), and nitric oxide (NO) assays by exhibiting 86.32, 50.45, and 48.23% inhibition respectively. Thus, the contemporary work has substantiated that low cost CuNPs-Pl can be highly proficient alternate or substitute of synthetic formulations.
