Colloidal gold is a suspension (or colloid) of sub-micrometre-sized particles of gold in a fluid — usually water. The liquid is usually either an intense red colour (for particles less than 100 nm), or a dirty yellowish colour (for larger particles). Due to the unique optical, electronic, and molecular-recognition properties of gold nanoparticles, they are the subject of substantial research, with applications in a wide variety of areas, including electron microscopy, electronics, nanotechnology, and materials science.
Properties and applications of colloidal gold nanoparticles strongly depend upon their size and shape. For example, rodlike particles have both transverse and longitudinal absorption peak, and anisotropy of the shape affects their self-assembly.
Read more about Colloidal Gold: History, Synthesis, Electron Microscopy
Famous quotes containing the word gold:
“Don different from those regal Dons!
With hearts of gold and lungs of bronze,
Who shout and bang and roar and brawl
The Absolute across the hall,”
—Hilaire Belloc (1870–1953)