Eco-friendly Synthesis, Characterization, and Antimicrobial Study of Mono Metallic Silver Nanoparticles from Khaya senegalensis Aqueous Stem Bark Extract

Healthy Khaya senegalensis stem bark were collected from the Billiri area and were carefully washed under running water, rinsed multiple times with distilled water, and then allowed to dry in the shade to eliminate any remaining moisture. Using a mortar and pestle, the dried materials were ground into a fine powder which was used in making the extract. 10ml of Khaya senegalensis stem bark extract was added to 100ml of 0.01 M aqueous AgNO3 solution. On the hot plate, the mixture was heated to 60°C while being stirred continuously and after some time, AgNPs were formed. The UV analysis showed a maximum absorbance of 2.926 AU at a matching wavelength (λ max) of 400 nm. An OH bond stretching may be the cause of a peak at 1845.08 cm-1. The shoulder peak of aldehydes belongs to the C=O group and is found at 1651.32 cm-1. The peak at 1314.99 cm-1 displays the fingerprint region of functional groups such as carboxylic and alcohol groups. The absorption peak at 1089.75 cm-1 could be the result of the CH2-CH3 bend. The FTIR analysis reveals that the aldehyde (C=O), hydroxyl (OH), and alkane (C-H) are the main agents in the conversion of Ag+ to g0 nanoparticles. The XRD result revealed that, the nanoparticles under study has face-centered cubic (fcc) and spinel-like structures, with biosynthesized AgNPs having an average particle size of 55.4 nm. Silver nanoparticles were tested for their antibacterial properties against two fungi, Candida albicans and A. niger, as well as gram-positive bacteria, K. pneumonia, and B. subtilis. several concentrations of silver nanoparticles were examined (100, 200, 300, 400, and 500 μg/L) against each pathogen.The inhibitory zone grows as silver nanoparticle concentration increases. The zones of inhibition for B. subtilis, K. pneumonia, A. niger, and C. albicans were 14.5 mm, 25.3 mm, 23.5 mm, and 19.5 mm, respectively, at a higher concentration of 500μg/L. Compared to all other pathogens under research, K. pneumonia showed a higher zone of inhibition for each concentration examined. The study's findings therefore showed that silver nanoparticles made from Khaya senegalensis stem bark extract had strong antibacterial activity against the pathogenic microorganisms investigated.