Table 1.

Effects of silver ion (Ag⁺) and AgNPs on bacterial cells.

effects	Ag+	AgNPs	comments	ref.
block respiratory enzyme and electron transfer	yes	yes	—	[8,12]
interact with DNA	yes	yes	—	[8]
interact with iron–sulfur groups	no	yes	—	[11]
interact with thiol groups in proteins	yes	no	—	[11]
induce the production of ROS (O2−, H2O2, OH.)	yes	yes	occurs only if free intracellular iron is present.	[11–12]
form a low molecular weight region at the center of the bacteria.	yes	no	—	[8]
electrostatic charge promotes greater interaction	no	yes	—	[8]
pass through biofilms	yes	yes	AgNPs act mainly in the range from 1 to 10 nm attached to the cell membrane surface.	[8,11]
induce the Fenton reaction and consequently kills apoptotic cells	yes	yes	subsequent oxidation of iron by H2O2 generates a hydroxyl radical, a powerful oxidant that attacks adjacent DNA.	[11,72,104–105]
“zombie effect”	yes	yes	after triggering apoptosis, AgNPs and Ag+ interact with the cellular components of the dead bacteria (RNA, polysaccharides, phospholipids, proteins, and DNA) creating new silver nanoparticles capped by the genetic material of the bacteria (AgNPs–bac).	[106]