Plant-mediated Synthesis and Characterization of Silver Nanoparticles from Broccoli Stem (Brassica oleracea var. italica) - Antimicrobial Performance

ABSTRACT The development of eco-friendly methods for nanoparticle synthesis has gained significant attention due to increasing environmental and health concerns associated with chemical synthesis. In this present study, silver nanoparticles (AgNPs) were synthesized using aqueous extract of Brassica oleracea (broccoli) stem ,an agricultural waste material ,as a reducing and stabilizing agent. The formation of AgNPs was initially confirmed by a visible color change from pale yellow to dark brown and further characterized using UV-visible spectroscopy ,Fourier transform infrared spectroscopy(FTIR) ,scanning electron microscopy (SEM) , and energy dispersive X-ray spectroscopy (EDX) .The UV-visible spectrum showed a characteristic surface plasmon resonance peak around 460 nm ,indicating successful nanoparticle synthesis. The SEM images show the synthesized silver nanoparticles are predominantly spherical in shape with aggregates.The biosynthesized AgNPs exhibited significant antibacterial activity against both Gram-positive and Gram-negative bacterial strains as demonstrated by agar well diffusion assay .The study highlights the potential of broccoli stem as a cost-effective, sustainable, and green resource for synthesis of biologically active silver nanoparticles with promising antimicrobial applications.