Fromnano- +particle.
nanoparticle (pluralnanoparticles)
- Anymicroscopicparticle less than about 100nanometers (nm) in diameter.
2005 February 22, Kenneth Chang, “Tiny Is Beautiful: Translating 'Nano' Into Practical”, inThe New York Times[1],→ISSN:Nanoparticles of various sorts are already found in products like sunscreen, paint and inkjet paper. More exotic varieties offer promise in medicine for sensitive diagnostic tests and novel treatments: the detection of Alzheimer's disease by finding a protein in spinal fluid, for instance, ornanoparticles that heat up and kill cancer cells.
In aerosol science, the term is often reserved for particles less than 50 nm in diameter;ultrafine particle is used for particles less than 100 nm in diameter.
nanoparticle on Wikipedia.Wikipedia