Cationic β-cyclodextrin-modified hybrid magnetic microspheres as chiral selectors for selective chiral absorption of dansyl amino acids

Abstract

Chirally selective functionalized magnetic microspheres show great potential in enantiomeric separations. In this study, a novel class of chiral magnetic selectors was developed by immobilization of vinylimidazolium-β-cyclodextrin chloride (VIMCD-Cl) on 3-methacryloxypropyltrimethoxysilane-modified iron oxide magnetic microspheres through a radical polymerization. The prepared chiral materials have regular three-dimensional core–shell architectures with an average particle size of about 580 nm and a high magnetization saturation of about 51 emu g⁻¹. Fourier transform-infrared spectra (FT-IR), thermogravimetric analysis (TGA) and elemental analysis confirmed that VIMCD-Cl was successfully polymerized on the surface of the magnetic microspheres. The prepared functional magnetic materials were then applied in the selective chiral absorption of three dansyl amino acids using microbatch technology. The results indicated that VIMCD-Cl immobilized magnetic microspheres (VIMCD-MNPs) possessed good enantioselectivities toward the three dansyl amino acids, and showed stronger interactions with the L-enantiomers during the chiral adsorption process. Furthermore, these functionalized chiral magnetic materials possess an excellent recyclability and can be used as effective chiral magnetic selectors for chiral separations.