title: Preparation and time-gated luminescence bioimaging applications of long wavelength-excited silica-encapsulated europium nanoparticles.
abstract: Silica-encapsulated luminescent lanthanide nanoparticles have shown great potential as biolabels for various time-gated luminescence bio-detections in recent years. The main problem of these nano-biolabels is their short excitation wavelengths within the UV region. In this work, a new type of silica-encapsulated luminescent europium nanoparticle, with a wide excitation range from UV to visible light in aqueous solutions, has been prepared using a conjugate of (3-isocyanatopropyl)triethoxysilane bound to a visible light-excited Eu(3+) complex, 2,6-bis(1',1',1',2',2',3',3'-heptafluoro-4',6'-hexanedion-6'-yl)-dibenzothiophene-Eu(3+)-2-(N,N-diethylanilin-4-yl)-4,6-bis(pyrazol-1-yl)-1,3,5-triazine (IPTES-BHHD-Eu(3+)-BPT conjugate), as a functionalized precursor. The nanoparticles, which are prepared by the copolymerization of the IPTES-BHHD-Eu(3+)-BPT conjugate, tetraethyl orthosilicate and (3-aminopropyl)triethoxysilane in a water-in-oil reverse microemulsion consisting of Triton X-100, n-octanol, cyclohexane and water in the presence of aqueous ammonia, are monodisperse, spherical and uniform in size. Their diameter is 42 ± 3 nm and they are strongly luminescent with a wide excitation range from UV to ∼475 nm and a long luminescence lifetime of 346 μs. The nanoparticles were successfully used for streptavidin labeling and the time-gated luminescence imaging detection of two environmental pathogens, cryptosporidium muris and cryptosporidium parvium, in water samples. The results demonstrated the practical utility of the new nanoparticles as visible light-excited biolabels for time-gated luminescence bioassay applications.
authors.affiliation: State Key Laboratory of Fine Chemicals, School of Chemistry, Dalian University of Technology, Dalian 116024, People's Republic of China.
authors.forename: Lu
authors.initials: L
authors.lastname: Tian
authors.forename: Zhichao
authors.initials: Z
authors.lastname: Dai
authors.forename: Lin
authors.initials: L
authors.lastname: Zhang
authors.forename: Ruoyu
authors.initials: R
authors.lastname: Zhang
authors.forename: Zhiqiang
authors.initials: Z
authors.lastname: Ye
authors.forename: Jing
authors.initials: J
authors.lastname: Wu
authors.forename: Dayong
authors.initials: D
authors.lastname: Jin
authors.forename: Jingli
authors.initials: J
authors.lastname: Yuan
mesh_terms: D003458:Cryptosporidium / Q000302:isolation & purification; D016785:Cryptosporidium parvum / Q000302:isolation & purification; D005063:Europium / Q000737:chemistry*; D008027:Light; D008163:Luminescent Measurements; D053758:Nanoparticles / Q000737:chemistry*; D012821:Silanes / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry*; D019809:Streptavidin / Q000737:chemistry / Q000378:metabolism; D013997:Time Factors; D014466:Ultraviolet Rays
chemical_list: C492426:(3-isocyanatopropyl) triethoxysilane; D012821:Silanes; D005063:Europium; D012822:Silicon Dioxide; D019809:Streptavidin