Comparison of antibacterial and antifungal activities of5-amino-2-mercaptobenzimidazole and functionalized NiOnanoparticles

Abstract

5-Amino-2-mercaptobenzimidazole (AMB), non-functionalized nickel oxide (n-NiO), and functionalized nickel oxide (f-NiO)nanoparticles were studied for antibacterial and antifungal activities, where the functionalization of nickel oxide nanoparticles wascarried out by AMB. The particle sizes of synthesized n-NiO and f-NiO nanoparticles were measured to be 16.07 and 20.86 nm,respectively. The XRD results of n-NiO and f-NiO nanoparticles were in perfect match with the diffraction pattern of NiO publishedin the JCPDS File No. 89-5881, which indicates that there is no effect on the crystal structure due to functionalization. FT-IRspectral studies show that f-NiO nanoparticles effectively bind with AMB by azomethine nitrogen. Furthermore, HR-SEM andEDAX results confirm the surface morphology and functionalization, respectively. The antimicrobial activity of AMB, n-NiO, andf-NiO nanoparticles dispersed in water was investigated. The antibacterial activity was evaluated against the bacteriaStaphylo-coccus aureusandPseudomonas aeruginosa, while the antifungal activity was evaluated against the fungiAspergillus nigerbyusing the agar well-diffusion method. The f-NiO nanoparticles exhibit excellent antibacterial and antifungal activities comparedwith n-NiO nanoparticles and AMB. The increased effect of f-NiO nanoparticles might be due to enhanced dispersibility andinteraction of NiO nanoparticles with membrane and intracellular proteins of bacteria and fungi.