An amino-functionalized monodispersed silica with different particle size of 310–780 nm has been synthesized by direct cocondensation of 3-aminopropyltrimethoxysilane (APTMS), [3-(2-aminoethylamino) propyl] trimethoxysilane (AEAP-TMS), or 3-[2-(2-aminoethylamino)ethylamino] propyltrimethoxysilane (AEAEAPTMS) with tetramethoxysilane [56].