Mutation, morphological and environmental change are the reason for the rise of multi-drug resistant bacteria. Nanoparticles with antibacterial activity have the potential to decrease the evolution of these bacterial species by targeting numerous biomolecules and preventing the formation of resistant strains. Metal-based nanoparticles have antibacterial action mechanisms which include reactive oxygen species production, cation release and membrane interaction. Due to the lack of a sturdy layer of peptidoglycan found in the cell wall, damage caused by physical interactions between itself and the NPs is more severe in Gram-negative bacteria. Another reason for Gram-negative bacteria's vulnerability to NPs is because of the presence of a negative charge which has a greater affinity towards positive ions released by NPs which contributes to the absorption of ions which results in inner cell damage. Iron oxide nanoparticles show enhanced antibacterial activity against gramnegative bacteria. The main mechanism by which these particles showed antibacterial activity is because of oxidative stress generated by ROS. Damage to proteins and DNA in bacteria can be induced by ROS which includes superoxide radicals, hydroxyl radicals, hydrogen peroxide, and singlet oxygen. )