Amino- and carboxyl-functional groups were covalently
coupled to the surface of silica nanoparticles easily, then SiO2–
COOH nanoparticles self-assembled film were formed on silicon
by amidation successfully. One layer relative close-packed
SiO2–COOH nanoparticles were arranged on silicon wafer.
Compared to the existing methods, it is evident that covalently
bonding of carboxyl groups of silica nanoparticle to aminosilane
groups on silicon is an effective method of bonding silica
nanoparticles. It is envisaged that functionalized nanoparticle
assemblies will serve as a platform for further assembly of
relevant information such as nanoparticle, biomolecule, fluorescence
indicator and so on.