International Science Community Association Research Journal of Recent Sciences 15 4 2026 10 2 Green Synthesis and Characterization of Silver and Copper Nanoparticles 12 19 EN M Kushalatha 1 Biochemistry department, Maharani Lakshmi Ammanni College for Women Autonomous, Bangalore, India H R Umesh 2 Biochemistry department, Maharani Lakshmi Ammanni College for Women Autonomous, Bangalore, India B S Jyothsna 1 Department of Botany, Government Science College, N.T. Road, Bangalore-01, Karnataka, India S Deepashree Chaitra 2 Department of Botany, Government Science College, N.T. Road, Bangalore-01, Karnataka, India B. Kavitha 1 Department of Microbiology, Nrupathunga University, Bengaluru, Karnataka, India Kumar M. B. Bindu 2 Department of Microbiology, Nrupathunga University, Bengaluru, Karnataka, India G. Priya 3 Department of Microbiology, Nrupathunga University, Bengaluru, Karnataka, India B. Mamatha 4 Department of Microbiology, Nrupathunga University, Bengaluru, Karnataka, India > Research Paper 2026 4 11 2026 10 2 The growing incidence of microbial contamination and the rise of antibiotic resistance have accelerated the need for effective and environmental friendly antimicrobial solutions. Silver and copper nanoparticles have emerged as promising candidates in nanomedicine due to their broad-spectrum antimicrobial activity. In this study, these nanoparticles were synthesized using a green approach with medicinal plants (Calotropis gigantea and Leucasaspera) and spices (Piper nigrum, Cinnamomum cassia, and Elettaria cardamomum). This plant-based synthesis method provides a cost-effective and eco-friendly alternative to traditional chemical techniques. The formation of nanoparticles was confirmed through UV–Visible spectroscopy. Silver nanoparticles displayed characteristic surface plasmon resonance peaks between 400–450 nm, while copper nanoparticles showed absorbance peaks in the 500–550 nm range, indicating successful synthesis. The antimicrobial activity of the nanoparticles was assessed using the agar disc diffusion method against bacterial strains (Staphylococcus aureus, Bacillussubtilis, Pseudomonas spp. and Salmonella spp.) and fungal species (Penicillium and Alternaria). Both types of nanoparticles exhibited strong antibacterial effects against all tested bacteria at a concentration of 100 μL. Among the fungi, Penicillium species were highly sensitive to the nanoparticles, whereas Alternaria showed limited susceptibility. Of the plant sources used, Leucas aspera, Calotropis gigantea, Piper nigrum, and Cinnamomum cassiawere particularly effective in promoting nanoparticle synthesis with enhanced antimicrobial activity. Our results demonstrate that plant-mediated synthesis of silver and copper nanoparticles is a sustainable and efficient approach for developing antimicrobial agents, with potential applications in nanomedicine, food safety, and biomedical materials. Copyright@ International Science Community Association