What is the difference between gold colloids and gold nanoparticles?

Answer 1

Gold colloids have multiple definitions. They have been used for many years as a dietary supplement (see http://www.purestcolloids.com). Gold colloids provide the body with minerals to maintain optimum health. They have been used for many years as a therapeutic for Arthritis. They have also been used in lateral flow applications such as in pregnancy tests (see http://www.bbigold.com). Gold nanoparticles, on the other hand, must possess properties that are specific for Nanotechnology applications. Sample nanotechnology applications include Resonance Light Scattering (RLS), Surface Enhanced Raman (SERS), in-vivo photothermal cancer therapy, imaging, and diagnostics. These applications demand monodispersity in size and shape with highly reactive surfaces because these applications depend on the quality of the individual nanoparticles, not just the properties of the nanoparticles in bulk. This is the definition of nanotechnology. In order to make gold nanoparticles suitable for these applications, the gold nanoparticles must have the following characteristics: 1. Provide rod shapes for in vivo applications. 2. Spherical gold nanoparticles that are not manufactured using thiol or citrate chemistry which result in unreactive, polydisperse gold nanoparticles. 3. Conjugations that are based on solid, covalent bonds, not adsorption which can results in lost conjugations. For gold nanoparticles see Nanopartz at http://www.nanopartz.com.