Silver has been known and used as a potent antimicrobial and wound-healing agent since ancient times. Silver compounds have had other ancient applications through which Greeks, Romans, and Egyptians used silver compounds as food and water preservative. Silver and silver-based antimicrobials were put away after the discovery of antibiotics. Meanwhile, with almost a century of application of antibiotics, resistant microbial strains appeared, and antibiotics are going to become less and less effective. Fortunately, our traditional weapon against microorganisms reemerged in a novel form to reclaim again. Silver nanoparticles (AgNPs) are well-known as potent and novel antimicrobial agents. AgNPs would disturb microbial growth by inhibiting phosphate absorption, collapsing the proton motive force, forming complexes with DNA, enzyme inactivation, and inhibiting glucose oxidation. It follows attacking the respiratory chain, changing the permeability and potential of the cell membrane, and inducing bacteria into a viable but non-culturable (VBNC) state and eventually killing them.
