Pro for nano offers silver nanoparticles (also called nano silver or colloidal silver). Silver nanoparticles are suspended in a carrier liquid and are supplied as a concentrated solution. Silver nanoparticles are available in two sizes: smaller particles - 15-20 nm and bigger particles - 35-40 nm. This product can be used to treat textiles, plastic, ceramic and metal surfaces. It works by releasing silver ions that inhibit growth of bacteria, fungi, yeast and viruses.