Evaluation of Antibacterial Efficacy of Green Synthesized Silver Nanoparticles from Moringa Oliefera Aqueous Root Extract

In this Research study, Silver Nanoparticles were green synthesized from Moringa oliefera plant aqueous root extract and different Characterization techniques including UV-Visible, FT-IR, SEM and XRD were all employed to ascertain the absorption peaks, functional group, surface morphology and crystalline size of the nanoparticles respectively. These nanoparticles green synthesized were applied against four different pathogens namely, S. typhi, S. aureus, Bacillus, Strep A. and the investigation showed that the silver nanoparticles synthesized were effective against the selected pathogens. From the UV-Vis spectral analysis, it was observed that highest absorption peaks appeared at 300nm reflecting the surface plasmon resonance of silver Nanoparticles from Moringa oliefera plant aqueous root extract which is characteristic of Silver Nanoparticles. From the FT-IR spectrum of the sample investigated, the peaks 3436.44 cm-1, 1638.75cm-1, 1384.50cm-1, 1090.80cm-1 and 798.08cm-1 were observed where the absorption band at 3436.44 cm-1, corresponds to the stretching due to N-H, while the band at 1638.75cm-1 is associated with C-H stretch of alkane and O-H stretching. The peak at 1384.50cm-1 shows C=C stretching, 1090.80cm-1 reveals the existence of C-H bending and 798.08cm-1 depicted C-O stretching. The SEM analysis revealed the shape of the nanoparticles as being crystalline in nature while XRD result admits that the average size of the green synthesized Ag NPs was 47.54nm using the Scherer’s formula. Augmentin was used as control at concentration of 300μg/L throughout antimicrobial studies. Different concentrations of 100, 200, 300, 400 and 500μg/L of Silver Nanoparticles were tested against each bacterium. It was discovered that with increase in concentrations of Silver Nanoparticles of all the pathogens, there generally appeared to be increase in inhibition zone. At higher concentration of 500μg/L, the zones of inhibition were in the following order; 26.5mm, 19.0mm, 17.5mm, and 17.0mm for S. typhi, Strep. A, S. aureus and Bacillus respectively. Although the green synthesized silver nanoparticles exhibited a good antibacterial activity against gram negative and gram-positive bacteria, for each concentration investigated, S. typhi, demonstrated higher zone of inhibition as opposed to all other bacteria investigated in this research.