This study explores the green synthesis of silver (Ag-NPs), copper (Cu-NPs), and silver-copper bimetallic nanoparticles (Ag-Cu Bimetallic NPs) using the leaf extract of Peganum harmala, a sustainable and renewable plant source. This eco-friendly synthesis method avoids hazardous chemicals and minimizes waste, advancing the principles of green nanotechnology. Characterization demonstrated distinct properties
Ag-NPs, Cu-NPs, and Ag-Cu bimetallic NPs exhibited surface plasmon resonance peaks at 425 nm, 555 nm, and 525 nm, respectively, and crystallite sizes of 21.42 nm, 21.40 nm, and 26.29 nm as confirmed by X-ray diffraction. Morphological analysis revealed spherical Ag-NPs, flake-like Cu-NPs, and a mix of cubic and spherical Ag-Cu NPs. Catalytic activity tests showed Ag-Cu bimetallic NPs achieved 95% degradation of methylene blue dye, highlighting their potential in environmental remediation. Antibacterial assays demonstrated that Ag-NPs exhibited the highest inhibition zones against Bacillus subtilis (27.0 mm) and Escherichia coli (27.67 mm), while Cu-NPs were effective against Klebsiella pneumoniae at higher concentrations. Ag-NPs also exhibited significant antifungal activity, particularly against Aspergillus niger (15.00 mm). Antioxidant assays revealed Ag-Cu bimetallic NPs displayed the highest free radical scavenging capacity (59.18%), followed by Ag-NPs (35.41%). Cytotoxicity tests indicated Ag-Cu bimetallic NPs had an IC