Antibacterial Effects of Silver Nanoparticle-doped “Black Physician: Tar”

Bilgiç E., Gürkan S., Ak F., Özgen A.

Istanbul Gelisim University Journal of Health Sciences, sa.28, ss.69-78, 2026 (TRDizin)

Özet

Aim: This study evaluated the antibacterial activity of silver nanoparticles (AgNPs) synthesized using Juglans regia (walnut) leaf extract and coated with Cedrus libani tar against Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria.
Method: AgNPs were biosynthesized using walnut leaf extract as the reducing agent and subsequently coated with cedar tar. The antibacterial activities of the individual components (walnut extract and tar), uncoated AgNPs, and tar-coated AgNPs were assessed via standard disc diffusion assays and compared with conventional antibiotics.
Results: Both walnut extract and tar exhibited inherent antibacterial properties, though they were less effective than standard antibiotics. AgNPs synthesized with walnut extract showed enhanced antibacterial activity; incorporation of tar further improved performance, yielding inhibition zones comparable to those produced by antibiotics against both bacterial strains.
Conclusion: Tar coating synergistically enhanced the antibacterial efficacy of biosynthesized AgNPs without requiring higher nanoparticle concentrations. Tar-coated AgNPs synthesized using walnut leaf extract may therefore serve as promising alternative antibacterial agents.

Aim: This study evaluated the antibacterial activity of silver nanoparticles (AgNPs) synthesized using Juglans regia (walnut) leaf extract and coated with Cedrus libani tar against Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria.
Method: AgNPs were biosynthesized using walnut leaf extract as the reducing agent and subsequently coated with cedar tar. The antibacterial activities of the individual components (walnut extract and tar), uncoated AgNPs, and tar-coated AgNPs were assessed via standard disc diffusion assays and compared with conventional antibiotics.
Results: Both walnut extract and tar exhibited inherent antibacterial properties, though they were less effective than standard antibiotics. AgNPs synthesized with walnut extract showed enhanced antibacterial activity; incorporation of tar further improved performance, yielding inhibition zones comparable to those produced by antibiotics against both bacterial strains.
Conclusion: Tar coating synergistically enhanced the antibacterial efficacy of biosynthesized AgNPs without requiring higher nanoparticle concentrations. Tar-coated AgNPs synthesized using walnut leaf extract may therefore serve as promising alternative antibacterial agents.