the simple and effective method is formation of amide bonds between peptide and the functional group of nanoparticle. therefore you should optimized the surface of iron oxides by suitable ligand that contains free NH2 or COOH group.

You should optimized the surface of iron oxides by suitable ligand that contains free NH2 or COOH group since formation of amide bonds between peptide and functional group of nanoparticle is a simple and effective method.

Kunal Pal, you simply copied Aahra Karami's answer and re-arranged it. You offered no original thought at all. This helps no one and does nothing positive for whatever reputation you are trying to establish with your cut and paste skills.