Bioengineered synthesis of phytochemical-adorned green silver oxide (Ag 2 O) 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 Ag 2 O is associated with the use of toxic chemicals and organic solvents. To circumvent this hurdle, herein silver oxide quantum dots (Ag 2 O-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 (∼ 9 nm vs. ∼ 100 nm). Silver and oxygen elements were found in the bio-synthesized Ag 2 O 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 Ag 2 O 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 Ag 2 O-QDs using ultrasonic-irradiation to develop versatile and green biomedical products.