Table 3.

Examples of heavy metals with antimicrobial properties

Metal cations	Activity towards microorganism	References
Cadmium, Cd2+	Reacts with sulphdryl groups on various intracellular proteins	140
Copper, Cu2+	Membrane‐bound copper ions may undergo Cu(I) to Cu(II) redox cycle, catalysing formation of highly toxic hydroperoxide radicals (R‐OOH)	58, 141, 142
Cobalt, Co2+	Competes with zinc for the active site of urease, thus inhibiting growth of Helicobacter pylori	143
Silver, Ag+	Interacts with intracellular components to suppress expression of enzymes and proteins essential for ATP production and condenses DNA, thus impairing replication	73
Zinc, Zn2+	Inhibits nutrient uptake, acid production and glycolysis in oral pathogens and rhinoviral replication. Interferes with proton transfer	65, 144, 145