Multifunctional nanoparticles possessing magnetic,long-lived fluorescence and bio-affinity properties for time-resolved fluorescence cell imaging

摘要

Multifunctional nanoparticles possessing magnetic, long-lived fluorescence and bio-affinity properties have been prepared by copolymerization of a conjugate of (3-aminopropyl)triethoxysilane bound to a fluorescent Eu~(3+) complex, 4,4'-bis( 1", 1",1"-trifluoro- 2",4"-butanedion-4"-yl)chlorosulfo-o-terphenyl-Eu~(3+) (APS-BTBCT-Eu~(3+)), free (3-aminopropyl)triethoxysilane (APS) and tetraethyl orthosilicate (TEOS) in the presence of poly(vinylpyrrolidone) (PVP) stabilized magnetic Fe3O4 nanoparticles (~10nm) with aqueous ammonia in ethanol. The nanoparticles were char acterized by transmission electron microscopy (TEM), spectrofluorometry and vibrating sample magnetometry methods. The direct-introduced amino groups on the nanoparticle's surface by using free APS in nanoparticle preparation facilitated the surface modification and bioconjugation of the nanoparticles. The nanoparticle-labeled transferrin was prepared and used for staining the cultured Hela cells. A time-resolved fluorescence imaging technique that can fully eliminate the fast-decaying background noises was developed and used for the fluorescence imaging detection of the cells. A distinct image with the high ratio of signal to noise (S/N) was obtained.