Background: The present study deals with new microwave assisted green, costeffectiveness,
synthesis of metal nanoparticles using aqueous leaf extracts. The plant extracts with
metal precursors were used to made eco-friendly/ biodegradable metal nanoparticles through
conventional and microwave irradiated methods. The iron and silver nanoparticles are one of them.
Methods: Synthesized AgNPs and FeNPs were primarily characterized by UV-Vis spectrophotometer
and further evaluated with FTIR and Atomic Force Microscopy (AFM) techniques. AgNPs and FeNPs were studied for
antimicrobial activity against various human pathogenic microorganisms E. coli, V. cholerae (Non-0319), Shigella
flexneri (16), Klebsiella pneumoniae (BCH-271), V. Cholerae (Non-0319-CSK 6669), S. pneumoniae, S. aureus, Shigella
dysenteriae using disc diffusion methods.
Results: The synthesized silver nanoparticles using aqueous leaf extracts of P. guajava and Camellia sinensis showed
maximum absorption peak at 420nm and 421nm respectively and iron nanoparticles synthesized using aqueous leaf
extracts of Mangifera indica showed maximum absorption peak at 315nm. The AFM images of sample revealed the
presence of metal nanoparticles and particle size was found as 42nm, synthesized under microwave in presence of plant
extracts (P.guajava). 16nm and 52nm sized nanoparticles were synthesized under conventional methods using aqueous
leaf extract of Camellia sinensis and Mangifera indica. Silver nanoparticles synthesized using aqueous leaf extracts of
Camellia sinensis showed antibacterial activity against various pathogenic microorganisms E. coli (9mm), V. cholerae
(Non-0319) (8mm), Shigella flexneri (16) (8mm), Klebsiella pneumoniae (BCH-271) (10mm), V. Cholerae (Non-0319-
CSK 6669) (9mm), S. pneumoniae (6mm), S. aureus (No), Shigella dysenteriae (No). Silver nanoparticles and iron
nanoparticles synthesized using aqueous leaf extract of P. guajava and Magnifera indica did not show any zone of
inhibition against various pathogenic microorganisms.
Conclusion: Aqueous leaf extracts are useful for the preparation of metal nanoparticles under microwave irradiation and
conventional methods through green processes. The silver nanoparticles synthesized using aqueous leaf extract of
Camellia sinensis showed antibacterial activity against various human pathogenic microorganisms.