Abstract:
Silver nanoparticles were synthesized using eco-friendly method with extract
of Carica papaya as reducing and stabilizing agent. The silver precursor used
was silver nitrate solution. A visible colour change from colourless to reddish
brown confirmed the formation of the nanoparticles and the UV-Vis spectroscopy
showed surface plasmon resonance of 435 nm for the silver nanoparticle.
The mean particle size was 250 nm while the polydispersity index was
0.22. The antimicrobial activity of the synthesized nanoparticles was studied
against Pseudomonas aeruginosa, Escherichia coli, Bacillus subtilis and Staphylococcus
aureus. The silver nanoparticles biosynthesized showed satisfactory
antimicrobial activity against the test isolates. Antimicrobial property of
the nanoparticles was similar (P > 0.05). Generally, MIC values of the samples
against the microorganisms tested ranged from 25 - 100 mg/ml. Pseudomonas
aeruginosa was most sensitive while Staphylococcus aureus and Bacillus subtilis
were least sensitive to the silver nanoparticles.
