title: Synthesis of porous upconverting luminescence α-NaYF4:Ln(3+) microspheres and their potential applications as carriers.
abstract: The present work reports a self-sacrificing template strategy to synthesize porous α-NaYF4 microspheres via the reaction of as-prepared Y(OH)CO3·H2O@SiO2 with NH4F and NaNO3 solutions. XRD, SEM, TEM and N2 adsorption-desorption measurements were used to characterize the resulting product. The surface SiO2 shell was shown to play a vital role in size and shape control and porosity formation. A possible reaction mechanism was explored in terms of a surface-protected etching and ion-exchange reaction process. To explore their application potential, the storage and release behavior of Rhodamine 640 dye in the porous α-NaYF4 microspheres was investigated, showing a relatively high loading efficiency and a sustained release ratio. Under near-infrared (NIR) irradiation, porous α-NaYF4 microspheres doped with lanthanide ions showed typical upconverting luminescence characteristics that can convert NIR photons to ultraviolet/visible photons. The above features and properties indicate that our present porous upconverting luminescence particles are promising in biological applications as luminescence imaging agents and drug carriers.
authors.affiliation: State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, Changchun 130012, People's Republic of China. whdi@jlu.edu.cn wpqin@jlu.edu.cn.
authors.forename: Changjian
authors.initials: C
authors.lastname: Lv
authors.forename: Weihua
authors.initials: W
authors.lastname: Di
authors.forename: Zhihe
authors.initials: Z
authors.lastname: Liu
authors.forename: Kezhi
authors.initials: K
authors.lastname: Zheng
authors.forename: Weiping
authors.initials: W
authors.lastname: Qin