Silver has been used as biocide for medical purposes since the 1930s. Today nanometric size silver particles are used to prevent unpleasant odour caused by bacteria in sport shirts or socks .

Gold nanoparticles ( AuNPs ) present the many advantages of displaying relative biocompatibility, high light absorption and strong optical scattering properties. They are therefore good candidates to be used as probes for cancer imaging .

Membranes for water purification are used in many applications and different types of membranes are being developed at the moment. No membrane can filter and purify water entirely, but improvements using novel kinds of membranes are made.

The filter could be used to recycle sewage on a space station, but the main focus is the use of ultra pure water in the fabrication of semiconductors.