Qian Haisheng, Li Zhengquan, Zhang Yong
Division of Bioengineering, Faculty of Engineering, Blk, E3A-04-15, National University of Singapore, 7 Engineering Drive 1, 117574, Singapore.
Nanotechnology. 2008 Jun 25;19(25):255601. doi: 10.1088/0957-4484/19/25/255601. Epub 2008 May 14.
Compared to conventional down-conversion fluorescent materials, NIR-to-visible up-conversion fluorescent materials which emit visible light upon near-infrared (NIR) excitation are better suited for biodetection/bioimaging due to their advantages such as minimum photo-damage to living organisms, weak background fluorescence, low signal-to-noise ratio and high detection sensitivity. Uniform hexagonal NaYF(4) (β-NaYF(4)) nanocrystals with up-conversion fluorescence were synthesized. Monodisperse polystyrene nanospheres with an average size of 400 nm in diameter, tagged with different color β-NaYF(4) nanocrystals, were prepared using a miniemulsion polymerization method. More than 20 β-NaYF(4) nanocrystals were encapsulated in a single polystyrene nanosphere. The nanospheres emit multicolor NIR-to-visible up-conversion fluorescence upon excitation at a wavelength of 980 nm. The nanospheres could be used for a variety of biological applications which require high-sensitivity detection of biomolecules.
与传统的下转换荧光材料相比，近红外到可见光的上转换荧光材料在近红外（NIR）激发下发出可见光，由于其对生物体的光损伤最小、背景荧光弱、信噪比低和检测灵敏度高等优点，更适合用于生物检测/生物成像。合成了具有上转换荧光的均匀六方相NaYF₄（β-NaYF₄）纳米晶体。采用微乳液聚合方法制备了平均直径为400 nm、标记有不同颜色β-NaYF₄纳米晶体的单分散聚苯乙烯纳米球。单个聚苯乙烯纳米球中封装了20多个β-NaYF₄纳米晶体。这些纳米球在980 nm波长激发下发出多色近红外到可见光的上转换荧光。这些纳米球可用于多种需要高灵敏度检测生物分子的生物应用。
