Bioengineered synthesis of phytochemical-adorned green silver oxide (Ag2O) nanoparticles via Mentha pulegium and Ficus carica extracts with high antioxidant, antibacterial, and antifungal activities

Silver oxide nanoparticles have various biomedical and pharmaceutical applications. However, conventional nanofabrication of Ag2O is associated with the use of toxic chemicals and organic solvents. To circumvent this hurdle, herein silver oxide quantum dots (Ag2O-QDs) were synthesized quickly (3 min) via the use of ultrasonic irradiation and plant-extract. Additionally, due to ultrasonic irradiation's effect on cell-wall destruction and augmentation of extraction efficiency, ultrasonic was also used in the preparation of Mentha pulegium and Ficus carica extracts (10 min, r.t) as natural eco-friendly reducing/capping agents. The UV-Vis result indicated a broad absorption peak at 400-500 nm. TEM/SEM analysis showed that ultrasound introduced a uniform spherical particle and significantly reduced particle size compared to the conventional heating method (similar to 9 nm vs. similar to 100 nm). Silver and oxygen elements were found in the bio-synthesized Ag2O by EDS. The FTIR and phenol/flavonoid tests revealed the presence of phenol and flavonoid associated with the nanoparticles. Moreover, nanoparticles exhibited antioxidant/antibacterial/antifungal activities. The MIC and MBC results showed the Ag2O QDs synthesized with M. pulegium extract have the highest antibacterial activity against E. coli (MBC=MIC:15.6 ppm), which were significantly different from uncoated nanoparticles (MBC=MIC:500 ppm). The data reflects the role of phyto-synthesized Ag2O-QDs using ultrasonic-irradiation to develop versatile and green biomedical products.

Automated summary

This study successfully synthesized silver oxide quantum dots using ultrasonic irradiation and plant extract, demonstrating their potential applications in the biomedical field with properties such as antioxidant, antibacterial, and antifungal activities. The method presented in this study can be used to develop eco-friendly silver oxide nanoparticles for various biomedical applications.