Preparation of Fluorescent-magnetic Nanocomposites and Surface Modification with Bovine Serum Albumin

摘要

Introduction: Fluorescent and magnetic core/shell nanoparticles have been widely researched in nanobioscience field. Fluorescent-magnetic nanocomposites can be obtained by reverse microemulsion method and the Stober approaches. Fluorescent-magnetic nanocomposites with surface modification have many potential applications. In this study, biology molecule (BSA) was conjugated on the surface of fluorescent-magnetic nanocomposites. The surface functional and biocompatible nanocomposites were successfully synthesized, they could be used for bioanalytical assays and biomedical applications. Materials & Methods:FeCl_3-6H_2O, FeSO_4-7H_2O, tetraethylorthosilicate (TEOS), 3-aminopropyltriethoxysilane (APTES), 1-(3-Dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC), fluorescein isothiocyanate (FITC), CdTe quantum dots (CdTe QDs), bovine serum albumin (BSA). All reagents were analytical grade. Fe_3O_4 were firstly obtained by chemical co-precipitation, and then two kinds of bifunctional nanocomposites (Fe_3O_4@SiO_2@FITC, Fe_3O_4@SiO_2@CdTe) were prepared by the Stober method. BSA was conjugated on the surface of Fe_3O_4@SiO_2@FITC nanoparticles activated by EDC. Results & Discussion: The FTIR and FL show that both Fe_3O_4@SiO_2@CdTe and Fe_3O_4@SiO_2@CdTe retained fluorescence characteristics and magnetic responsibility. The fluorescence of Fe_3O_4@SiO_2@CdTe is different from CdTe, while the fluorescence of Fe_3O_4@SiO_2@FITC did no change significantly compared to FITC, the distinction is due to the different fluorescent mechanisms of QDs and dye. The XPS shows that BSA has successfully grafted on Fe_3O_4@SiO_2@FITC nanoparticles. The nanocomposites conjugated BSA was obtained in this study, the products were detected by FTIR, FL and XPS. The results demonstrate that surface functional and biocompatible nanocomposites were obtained; the nanoparticles with biofunction are expected to have potential application in the bioscience such as luminescence detection, magnetic separation, drug delivery etc.