Dendrimer modified magnetic nanoparticles for immobilized BSA: a novel chiral magnetic nano-selector for direct separation of racemates

Abstract

Nanomaterials capable of performing highly efficient chiral separations represent promising materials with potential applications in biomedical research. In this paper, we report the development of a new microwave-assisted method for the preparation of polyamidoamine (PAMAM)-magnetite nanoparticles (PMNPs) and their use in the immobilization of BSA to form Fe₃O₄@SiO₂@PAMAM–BSA (BSA–PMNPs) chiral magnetic nanoparticles. The binding capacity of BSA to PMNPs increases with each generation of growth, which can enhance the chiral discrimination of magnetite prepared in this way. UV-vis spectrophotometry and confocal laser scanning microscopy were used to evaluate the binding capacity of BSA. The activity of the BSA on the PMNPs was tested using an immunoaffinity approach, with the eluent being assayed by sodium dodecyl sulfate polyacrylamide gel electrophoresis. The functional magnetic nanoparticles were then used for the direct separation of chiral amino acids, and could be readily separated from the reaction mixtures via the application of a magnetic field. The separation results indicated that the BSA–PMNPs showed much greater affinities for the (−)-enantiomers than the (+)-enantiomers, and effectively demonstrated the potential utility of this material for chiral separations.