Surface functionalized magnetic nanoparticles for separation of chiral biomolecules, pharmaceuticals and endocrine disrupting compounds

Abstract

In the past decade, synthesis of nanoparticles has been intensively developed not only for fundamental scientific interest but also for many technological applications. Among the others, magnetic nanoparticles (MNPs) have the advantages of good dispersibility in various solvents, high surface area and strong magnetic responsivity. In this work, magnetic Fe3O4 nanoparticles were synthesized by chemical co-precipitation method and surface of magnetic nanoparticles were functionalized with either carboxymethyl-?-cyclodextrin (CMCD) or amino ?-cyclodextrin (?-CDen) via layer-by-layer methods. Functionalized particles were characterized with FTIR, TEM, XPS, XRD, VSM and TGA etc. Cyclodextrin derivatives were synthesized and applied as chiral selectors because of their favorable properties (stability, low cost, UV transparency, inertness, etc.). Initially, CMCD modified magnetite silica nanoparticles (Fe3O4/SiO2/CMCD MNPs) were used to adsorb single amino acid enantiomers namely D- and L- tryptophan (Trp), D- and L-phenylalanine (Phe) and D- and L-tyrosine (Tyr) from aqueous solution. Chiral separation of racemic aromatic amino acids, DL-tryptophan (Trp), DL- phenylalanine (Phe) and DL- tyrosine (Tyr) were also achieved in this study employing the concept of selective adsorption and mechanism of enantioseparation was explored. Furthermore, sorption separation of ?-blocker, propranolol utilizing Fe3O4/SiO2/CMCD MNPs from aqueous solution was studied in details. Afterwards, amino ?-cyclodextrin (?-CDen) bonded superparamagnetic Fe3O4 nanoparticles with combined effect of inclusion properties of cyclodextrin and magnetic properties of iron oxide were used as potential adsorbent for removal of two pharmaceuticals, carbamazepine (CBZ) and naproxen (NAP) and an endocrine disrupting agent, bisphenol A (BPA) from aqueous solutions. Finally, desorption and regeneration studies were carried out in different conditions. Experimental results show that ?-cyclodextrin derivative conjugated MNPs are promising tool for separation of chiral biomolecules as well as separation/removal of pharmaceuticals, endocrine disrupting compounds and beta-blocking agents from aqueous solution.