The novel magnetic adsorbent was prepared by functionalization of magnetic nanoparticles with Poly-gamma-glutamate (PGA), and the sorbent is named as PGA@SiO2@Fe3O4. The composite nanoparticles were further used in retrieval of heavy metal ions such as Pb(II) from the aqueous medium. The preparation of PGA@SiO2@Fe3O4 involves a two-step process: (i) surface modification of Fe3O4 nanoparticles by ethyl orthosilicate (TEOS) to form SiO2@Fe3O4, (ii) surface functionalization of SiO2@Fe3O4 nanoparticles by free radical copolymerization to form a cross-linking magnetic PGA@SiO2@Fe3O4 nanoparticles. The chemical structure of the PGA, Fe3O4, SiO2@Fe3O4, and PGA@SiO2@Fe3O4 was characterized by 1H-NMR, and FTIR. The nano-size and surface morphologies of the adsorbent were analyzed by SEM and DLS. Finally, the adsorbent was used to adsorb Pb (II), and the effects of different factors such as initial concentration, adsorption time, adsorption dosage, pH, and temperature on the adsorbent and adsorption were studied.nbsp