Green Synthesis and Bioactive Potential of Silver Nanoparticles: Antimicrobial and Anticancer Evaluation

The current work describes the green synthesis and characterization of silver nanoparticles (AgNPs) and their assessment with antimicrobial, bioassay, and anticancer properties. UV-vis spectroscopy was used to verify the formation of nanoparticles by a distinct plasmon resonance point at 440 nm, which corresponds to the average plasmon resonance of silver nanoparticles (400-460 nm). FTIR analysis identified the presence of functional groups of hydroxyl, carbonyl and ether/ alcohol, which is the evidence of the use of phytochemicals in stabilizing the nanoparticles. SEM-imaging revealed spherical-to-quasi-spherical sized AgNPs with diameter between 52 and 84 nm, with low agglomeration and uniform distribution reflecting stability and biomedical application. Antibacterial tests revealed strong anti-microbial effects against Staphylococcus aureus, Bacillus subtilis, Escherichia coli and Klebsiella pneumoniae with an anti-microbial zone of 14-26 mm, which were more potent against antibiotics. Antifungal testing showed activity against Aspergillus flavus, but only slight inhibition of Aspergillus terreus and Aspergillus niger. The presence of dose-dependent cytotoxicity was shown in studies on bioassay against K. pneumoniae, where cell death was up to 73.61 per cent at the highest concentrations. Evaluation of anticancer activity with MCF-7 breast cancer cell line demonstrated that there was minimum concentration-dependent cell viability reduction, and the greatest reduction (21.8% viability) was at 2 µL concentration. In general, the prepared silver nanoparticles have positive multifunctional bioactivities, suggesting their potential in therapeutic and biomedical applications. Keywords: Silver nanoparticles, Green synthesis, Antibacterial activity, Bioassay, MCF-7 cell line