title: Fabrication of triple-layered magnetite/hydrogel/quantum dots via the molecular linkage of bi-functional diamines.
abstract: A multifunctional biomedical agent with magnetism, pH-sensitive, fluorescent properties was fabricated as a triple-layered magnetite/hydrogel/quantum dots. First, core-shell magnetic silica nanospheres (Fe3O4@SiO2) were synthesized via the sol-gel reaction of magnetite clusters with tetraethyl orthosilicate (TEOS), and the resuting magnetic particles were encapsulated with poly(N-isopropylacrylamide-co-acrylic acid) hydrogels through a free radical polymerization. The hydrogel-encapsulated magnetic particles were subsequently anchored by quantum dots (QDs) via the molecular linkage of bi-functional diamines. Diamine molecules effecrively induced the crosslinking between magnetic hydrogels and quantum dots. Among diamine linkers with different chain lengths (C-4, C-8, and C-12), C-8 diamine (1,8-diaminooctane) produced the maximal PL intensity for QD-bound hydrogels, indicating that C-8 diamine was an optimal cross-linker between hydrogels and QDs with surface carboxylic acid groups. The characteristic properties of the multifunctional nanocomposites were analyzed by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), zeta-potential meter, and photoluminescence (PL) spectroscopy.
authors.affiliation: Department of Chemical and Bio Engineering, Kyungwon University, San 65 Bokjeong-Dong, Sujeong-Ku, Seongnam, Gyeonggi-Do 461-701, Republic of Korea.
authors.forename: Sera
authors.initials: S
authors.lastname: Lim
authors.forename: Sangwha
authors.initials: S
authors.lastname: Lee
mesh_terms: D000588:Amines / Q000737:chemistry*; D003460:Crystallization / Q000379:methods*; D052203:Ferrosoferric Oxide / Q000737:chemistry*; D020100:Hydrogels / Q000737:chemistry; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008968:Molecular Conformation; D036103:Nanotechnology / Q000379:methods*; D045663:Quantum Dots; D013499:Surface Properties
chemical_list: D000588:Amines; D020100:Hydrogels; D046911:Macromolecular Substances; D052203:Ferrosoferric Oxide