
Nanoparticles
A nanoparticle is a microscopic particle with at least one dimension less than 100 nm. Nanoparticle research is an area of intense scientific research, due to a wide variety of potential applications in biomedical, optical, and electronic fields. The properties of many conventional materials change when formed from nanoparticles. This is typically because nanoparticles have a greater surface area per weight than larger particles which causes them to be more receptive to some other molecules.

Gold nanoparticle = yellow; molecules of the anti-cancer drug Taxol = white and red.

Stealth Coating (minimizes opsonization in biological applications) = blue; antibody conjugates (provides molecular specificity for targeting cells) = purple and red.

Schematic of a nanoparticle loaded with a drug in the core (purple) and a specific dye marker at the surface of the particle (blue dots).

Structure of the nanoparticles containing exactly 25 silver atoms (purple, green) and surrounding stabilizing components.

Gold atoms = magenta; sulfur atoms = yellow; carbon atoms = gray; hydrogen atoms = white.

Semiconductor nanoparticle (quantum dot) of lead sulfide with complete passivation by oleic acid, oleyl amine and hydroxyl ligands.

Palladium nanoparticle = blue; aluminum atoms= pink; oxygen atoms = red; hydrogen atoms =white; carbon atom = green.

Theranostic (having both a therapeutic and diagnostic function) nanoparticles (hydrophobic segments are visualized in green and hydrophilic segments in blue).

Illustration showing gold nanoparticle-protein conjugation.