Dear Mohd Hamza, You can incorporate the amine-functionalized graphene into the hydrolyzed TEOS sol during the sol gel process in  a one step hydrolysis. Crosslinking of your amine-functionalized graphene would be achieved during gelation.

Please read the article:

http://www.sciencedirect.com/science/article/pii/S0021979717300176

Thanks for the answer. The modified graphene with dodeclylamine and octadecylamine are hydrophobic. Thus this is why I was asking since the TEOS sol gel system contains many OH group contributed by ethanol and water.

There's a chance that TEOS reacts  with amines and will precipitate silica nano-particles.. better use amino-silanes.