INTRACELLULAR IMAGING APPLICATIONS OF RARE EARTH DOPED MULTIFUNCTIONAL METAL OXYSULPHIDE NANOMATERIALS
Julio Avalos, Ajith Kumar, L. Chris Mimun, Francisco Pedraza III, Dhiraj Sardar.
The University of Texas at San Antonio, San Antonio, TX.
Nanomaterials with multiple imaging features have drawn a lot of attention in the medical industry, where there is always a high demand for contrast agents to provide more information about intracellular level mechanisms. Rare-earth doped inorganic nanophosphors are the best choice for these applications due to several advantages including excellent optical properties, size, composition control, etc. In this work, we present a series of rare-earth doped metal oxysulphide hosts, M2O2S:Re (M = Gd,Y, Re=Yb,Er,Eu), as an alternate host with fluorescence efficiency equal or even higher than that of halides. Nanoparticles with sizes ranging from 20 - 200 nm were synthesized by thermal decomposition and homogeneous precipitation and were characterized by various techniques including X-ray diffraction, electron microscopy, optical absorption, and emission and magnetization experiments. Confocal imaging was done to confirm the internalization of the nanoparticles inside the cells. In vitro and in vivo animal imaging experiments show possible applications of this material in infrared optical imaging applications. Furthermore, magnetic imaging experiments show that the proposed material can also be used as a magnetic contrast agent in magnetic imaging applications. We conclude that the proposed material could find potential applications as a multimodal contrast agent in biomedical imaging. [This research was funded by the National Science Foundation Partnerships for Research and Education in Materials (NSF-PREM) grant N0-DMR-0934218 and by NIH/NIGMS MARC U*STAR GM07717.]