Yes Fatemeh

As a beginner its a good question nano chelating is the process which involves the bonding of ions and molecules to metal ions in the nano regime. It involves the formation or presence of two or more separate coordinate bonds between a polydentate (multiple bonded) ligand and a single central atom. Whereas nano coating is simply a coating where there is the chance of nano chelation. 

Depending upon your process of fabrication nanoparticles chelate with amino acids.

in chelating molecules are chemically and internally bond which can go base on a self-assembly method while the coating is an external layer that covers the material in nanoscale might be chemical/physiochemical or physical 

Thanks Sutripto Majumder.

I searched about method of chelating amino acids with nano particle, but I didn't find.

Do you have a method or article about iron chelating with amino acids?

Actually , I have free magnetic Fe3O4 and I want to produce nano iron fertilizer , but I didn't find a method of this . Methods that I found coat nano particles with organic matter like amino acid , but I don't know how is nano particle chelate fertilizer produced .

thanks Amin Shavandi for your help.

Fatemeh

I am sending some paper hope it will help you to clear your doubts. go through the different methods which ever is mentioned.