Biopolymeric Films Impregnated with Ficus carica Leaf Extract-Mediated Silver Nanoparticles and their Antimicrobial Activity  

This study evaluates chitosan- and agar-based composite films containing F. carica ethyl acetate extract-derived AgNPs. This work forms part of our systematic investigation of plant extract-mediated AgNPs; however, unlike our previously reported Centratherum anthelminticum seed-derived AgNPs, the present study employs a distinct plant source, phytochemical profile, nanoparticle characteristics, and antimicrobial response, which differentiates it from our previously published system. AgNP synthesis was optimized using 10 mM AgNO₃ and 500 µg/mL extract at pH 10 and 90°C. The solution-cast control films contained 250 mg polymer and 125 mg glycerol, while the nanocomposite films additionally contained 1 mg AgNPs per film. A dry film with casting density of ~5.91 mg/cm² and AgNP loading of ~15.72 µg/cm² was obtained. The AgNPs had an average particle size of 42.45 nm. Their incorporation was confirmed by FTIR, XRD, and FESEM-EDAX analyses. AgNPs enhanced tensile strength from 19.00 ± 0.62 to 23.08 ± 1.36 MPa for chitosan and from 105.31 ± 1.18 to 113.80 ± 1.35 MPa for agar films. Antibacterial activity against Staphylococcus aureus, Pseudomonas aeruginosa, and Proteus mirabilis was improved. For chitosan films, inhibition diameter increased from 7.67 ± 0.47, 7.67 ± 0.47, and 7.67 ± 0.47 mm for controls to 10.33 ± 0.47, 11.67 ± 0.47, and 9.67 ± 0.47 mm, respectively. For agar films, corresponding increases were from 7.67 ± 0.47, 7.67 ± 0.47, and 7.33 ± 0.47 mm to 12.67 ± 0.47, 18.67 ± 0.47, and 10.33 ± 0.47 mm. No measurable improvement over control values was observed for biopolymer-extract films. F. carica AgNPs show several advantages over C. anthelminticum AgNPs: they require a lower extract concentration (500 vs 1000 µg/mL), produce smaller particles (42.45 vs 46.8 nm), have a more negative zeta potential (−30.2 vs −22.0 mV), and have stronger antibacterial activity against P. aeruginosa (24.50 vs 15.67 mm). F. carica AgNP films also provide higher activity against P. aeruginosa in both chitosan (11.67 vs 9.67 mm) and agar films (18.67 vs 10.67 mm) and comparable activity against S. aureus, highlighting its antimicrobial potential.