Phyto-synthesized Zinc Sulfide Nanoparticles from Peels of Banana (Musa paradisiaca), a Promising Antibacterial Agent against Cholera Pathogen

Choleragenic strains of Vibrio cholera (i.e. V. cholera 01 and 0139) pathogen of cholera disease is one major indicator of flooding. Cholera had been an epidemic in Nigeria and its recent resurgent with several cases of fatality is a call for concern. Several treatments regimens are being employed but alternative approach such as nanomedicine using nanoparticles like Zinc sulfide needs more exploration in this regard. This research uses the peels of Musa paradisiaca as reducing, capping and stabilizing agent for the synthesis of Zn Sulfide nanoparticles. Fruits of M. paradisiaca were collected and identified using literature. Fine powder of the peel was made and the aqueous extract was obtained. The green extraction of ZnS NPs was carried out and the resulting ZnS NPs were characterize using XRD and TEM with particles size recorded on FESEM. An in vitro cytotoxicity, MIC tests and antibacterial assay were performed. GZnS NPs formed were spherical and whitish in colour. XRD spectrum of ZnS thin films display three broad peaks at 2θ = 28.69°, 48.23°, and 56.72°, these indicate the formation of the nanostructure. A typical HRTEM image of the green ZnS nanoparticles is displayed while the average size of the particle is 4.92 nm. Trends observed both in the cytotoxicity test and antibacterial assay suggest that increase in concentrations is proportional to increase in toxicity of GZnS nanoparticles. While the former pegged IC50 at values slightly above 400mg/ml, the latter demonstrated high efficacy of the GZnS nanoparticles against V. cholera. The MIC was 6mg/ml, which represents the minimum concentration at which inhibition of V. cholera occurred. This study showed that green zinc sulfide nanoparticles extracted using banana peels are active against V. cholera 0139. The size and characteristics of the GZnS NPs showed that they have a large surface area to foster effective antibacterial activities. These NPs also demonstrated increased antibacterial activities against the test organism with increase in concentrations, and since similar trend was observed in its cytotoxicity there is need for concentration regulation and monitoring while using them in cholera treatment so that consumer safety will be guaranteed.