| abstract |
A fluorescent nanoparticle comprising: a core, the core comprising a fluorescent silane compound and having a diameter of 25 nm to 200 nm; a silica shell on the core, wherein the silica shell is 25 nm to 800 nm thick and where the silica shell covers 10 to 100 percent of the surface area of the core; and a ligand, the ligand conjugated or coated on the surface of the fluorescent nanoparticle to form a bound fluorescent nanoparticle, the ligand covering 0.1 to 100 percent of the surface area of the core, characterized in that the core comprises organosilane having the general formula R (4-n) SiXn, where X is ethoxy, methoxy or 2-methoxy-ethoxy; R is a monovalent organic radical of 1 to 12 carbon atoms; and n is an integer from 0 to 3, and in which the monovalent organic radical comprises a mercapto functional organic group, and characterized in that the diameter of the fluorescent nanoparticle is from 50 nm to 1000 nm. |