Polymer Functionalization, Synthesis, Characterization, and Biological Evaluation of Silver Nanoparticles Using Cucurbita Maxima Leaf Extract

Green synthesis of silver nanoparticles (AgNPs) has garnered significant interest due to their distinctive antibacterial properties. This study presents a novel and eco-friendly approach for synthesizing AgNPs by employing fresh Cucurbita maxima leaf extract as a reducing agent to convert 1 mM AgNO₃ solution into AgNPs. The resulting AgNPs exhibited an average particle size of 4.62 ± 0.97 nm and were further functionalized with polyvinyl pyrrolidone (PVP) to enhance biological activities.

The synthesized PVP-functionalized AgNPs (PVP-b-AgNPs) were thoroughly characterized using high-resolution transmission electron microscopy (HR-TEM), X-ray diffraction (XRD), UV–visible spectroscopy, and Fourier-transform infrared spectroscopy (FTIR). HR-TEM analysis revealed the spherical shape and uniform dispersion of PVP-b-AgNPs.

The antibacterial activity of PVP-b-AgNPs was assessed against various bacterial strains. Additionally, the samples were evaluated for their antioxidant activity using established techniques. The biosynthesized b-AgNPs and PVP-b-AgNPs displayed excellent antioxidant activity, with percentages of 72.80% and 78.50%, respectively, in the H₂O₂ scavenging assay. In the antibacterial evaluation, PVP-b-AgNPs demonstrated superior inhibitory effects against Staphylococcus aureus compared to other bacterial strains. When compared to PVP and b-AgNPs, the synthesized PVP-b-AgNPs exhibited enhanced inhibitory potential against bacterial strains such as Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus at lower doses.

The findings suggest that the environmentally friendly synthesis of PVP-b-AgNPs holds promise for potential applications in the development of therapeutic biomedical sectors as an improved alternative to antibacterial agent. Furthermore, the synthesized AgNPs have potential utility in nanomedicine for encapsulating bioactive compounds.