Effect of silver nanoparticles on biofilm surface

Biofilm form thick polysaccharide layers that protect the organisms from the immune system and antibiotics. As a result, chronic infections are often hard to treat. Much research has been conducted to find out ways to counteract the biofilm. In this report, the optimal biofilm growth conditions of Escherichia coli (E. coli) and Pseudomonas aeruginosa (P. aeruginosa) were investigated. The in-vitro antimicrobial activity of silver nanoparticles was also tested against fully developed biofilm. The results indicated that concentrations of 5120µg/mL for exposure of 48hrs yield the best result in treating E. coli biofilms as bactericide. “Pits” were found in the bacteria cell wall and increased permeability of more silver nanoparticles. Higher concentrations and longer exposure of the silver nanoparticles gave better killing. This simple and cost-effective manner may be suitable for formation of similar types of bactericidal materials in future.Bachelor of Engineering (Chemical and Biomolecular Engineering