title: Highly luminescent Eu3+ chelate nanoparticles prepared by a reprecipitation-encapsulation method.
abstract: Aqueous suspensions of highly luminescent Eu3+ chelate nanoparticles are prepared by a novel reprecipitation-encapsulation method. An alkyl alkoxysilane encapsulation agent is included during the nanoparticle formation process, forming a nanoparticle encapsulation layer that inhibits aggregation as evidenced by UV-vis spectroscopy and atomic force microscopy. In addition, the encapsulated nanoparticles exhibit a small size (10 nm), intense luminescence, and excellent photostability. We estimate that the molar extinction coefficients of the approximately 10 nm particles are approximately 5.0x10(7) M-1 cm-1 with a luminescence quantum yield of 6%, indicating a luminescence brightness many times larger than that of conventional fluorescent dyes and comparable to that of colloidal semiconductor quantum dots. The small size, high brightness, highly red-shifted luminescence, and long luminescence lifetimes of the nanoparticles are of interest for luminescence labeling and sensing applications.
authors.affiliation: Key Laboratory of Luminescence and Optical Information, Ministry of Education, Institute of Optoelectronic Technology, Beijing Jiaotong University, Beijing 100044, China.
authors.forename: Hongshang
authors.initials: H
authors.lastname: Peng
authors.forename: Changfeng
authors.initials: C
authors.lastname: Wu
authors.forename: Yunfei
authors.initials: Y
authors.lastname: Jiang
authors.forename: Shihua
authors.initials: S
authors.lastname: Huang
authors.forename: Jason
authors.initials: J
authors.lastname: McNeill