Green Synthesis of Metallic Nanoparticles from Quercus Bark Extracts: Characterization and Functional Properties

Area of Science:

• Materials Science
• Nanotechnology
• Biotechnology

Background:

• Oak (Quercus) species offer ecological and medicinal benefits.
• Bark extracts are explored for green synthesis of metallic nanoparticles.
• Silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs) have diverse applications.

Purpose of the Study:

• To synthesize AgNPs and AuNPs using bark extracts from three Quercus species.
• To characterize the synthesized nanoparticles.
• To evaluate the antioxidant, antibacterial, antifungal, and cytotoxic properties of the nanoparticles and extracts.

Main Methods:

• Green synthesis of AgNPs and AuNPs using aqueous Quercus bark extracts.
• Characterization via UV-vis spectroscopy, Transmission Electron Microscopy (TEM), Dynamic Light Scattering (DLS), and Fourier-Transform Infrared Spectroscopy (FTIR).
• Assessment of total phenolic content, individual phenolic compounds (UPLC-PDA), antioxidant activity, antimicrobial activity, and cytotoxicity (HaCaT cell line).

Main Results:

• Rapid synthesis of variously shaped AuNPs (14-24 nm) and AgNPs (45-70 nm) was achieved.
• Raw extracts showed highest antioxidant activity; AgNPs and AuNPs demonstrated moderate activity.
• AgNPs (specifically AgQP) exhibited potent antibacterial and antifungal effects.
• AuNPs were non-cytotoxic, while AgNPs and raw extracts showed cytotoxicity after 48h.

Conclusions:

• Quercus bark extracts are effective for green synthesis of AgNPs and AuNPs.
• Synthesized nanoparticles possess significant bioactivity, particularly antimicrobial properties.
• Further research is needed to balance efficacy with safety, considering cytotoxic effects of AgNPs and extracts.