| dc.description.abstract | The development of eco-friendly and sustainable methods to synthesize silver
nanoparticles (AgNPs) is a rapid field in nanotechnology due to its eco-friendly
nature. In this study, five varieties of Annona leaves (Annona muricata, Annona
reticulata, Annona squamosa green, Annona squamosa red, and Annona glabra) were
used to synthesize AgNPs and the photocatalytic, antioxidant, and antimicrobial
properties were investigated. One mL of AgNO3 solution was mixed with 9 mL of the
extract. Initially, the formation of AgNPs was observed by a colour change at room
temperature after 24 hours. AgNPs were further confirmed by the UV-Vis
spectroscopy which displayed a plasmon resonance peak between 420-440 nm. The
size and shape of the AgNPs were analyzed by the scanning electron microscope and
the analysis showed that AgNPs are spherical with a size of ≈40 nm. The antioxidant
properties were analyzed by total flavonoid, total phenolic, and total antioxidant
contents. All three antioxidant assays confirmed that the AgNPs have higher
antioxidant activity than their respective water extracts. The photocatalytic activity
of 267 ppm and 4000 ppm Annona squamosa red AgNPs was analyzed using methyl
red under sunlight. The degradation of methyl red was achieved within 75 minutes.
The antibacterial properties of AgNPs and the water extracts were analyzed against
E. coli and S. aureus using the well diffusion method and showed a significant
difference (p= 0.001 and 0.03 respectively) in the zone of inhibition. Therefore, the
results confirmed that the green synthesis AgNPs from five varieties of Annona
plants can be used in a variety of medical applications. | en_US |
