Antimicrobial Evaluation and Characterization of Green Synthesized Silver Nanoparticles Using Annona muricata L. Leaf Extract

Aim: This study was aimed at assessing the antimicrobial activity of green-synthesized nanoparticles from Annona muricata l leaf extract.

Study Design: Plant preparations-Green synthesis of Silver Nanoparticles-Characterization (Ultra Violet-Visible, Fourier Transform-Infrared, Particle size Analysis)- Antimicrobial Evaluation using the clinical isolates.

Place and Duration of Study: Department of Pharmaceutical Chemistry, Madonna University, Elele, Department of Pharmaceutical and Medicinal chemistry, University of Nigeria Nsukka and Department of Microbiology and Biotechnology University of Nigeria, Nsukka between June 2021 to November 2021.

Methodology: Fresh plant leaves were collected, dried and grinded. 20g of the powder was used to generate the extract. 0.1698g of silver was used to produce silver nitrate (AgNO3). 50mls of the extract was mixed with 250mls of AgNO3 and incubated at 270C in the dark.The synthesized silver nitrate was centrifuged for 30minutes at 5000rpm.Green synthesis of silver nanoparticles (AgNPs) was done and the AgNPs produced were characterization using UV-Vis, FT-IR and Particle size analysis. Five clinical isolates were used for antimicrobial evaluation of the green synthesized nanoparticles.

Results: The silvery brown color was observed at 1 hour, indicating the formation of AgNPs. The UV- VIS showed a peak between 370-450nm. The FT-IR results confirmed phytochemicals in Annona muricata l and its roles as a bio-reductant and stabilizer on the surface of silver nanoparticles. The Particle size analysis result indicates an average particle size of 570nm. The results signify that the silver nanoparticles synthesized using the aqueous leaf extract of A. muricata l. were found to have promising antimicrobial activity against both Grampositive and Gram negative bacteria with the minimum inhibitory concentrations ranging from 5µg to 10 µg.

Conclusion: The synthesized silver nanoparticles of Annona muricata leaf extract exhibited an effective antimicrobial activity.