NaYF_4:Er^(3+),Yb^(3+)UCNPs为供体的均相荧光分析  

Homogeneous Phase Fluorescence Assay Based on NaYF_4:Er^(3+),Yb^(3+) UCNPs as Donors

作　　者：宋凯[1,2] 张庆彬[2] 赵军伟[2] 孔祥贵[2] 

机构地区：[1]长春师范学院生命科学学院,吉林长春130032 [2]中国科学院长春光学精密机械与物理研究所激发态重点实验室,吉林长春130033

出　　处：《光谱学与光谱分析》2013年第4期1005-1008,共4页Spectroscopy and Spectral Analysis

基　　金：国家自然科学基金项目(10904142;11204021;11204122);吉科教项目(2010-227);长春师范学院自科项目(2010-002)资助

摘　　要：在基于荧光共振能量传递(FRET)的均相分析中,小尺寸的上转换发光纳米晶(UCNPs)用作供体被认为有很大的优势。通过配体交换的方式制备了大小约12nm、表面带有氨基的水溶性NaYF4∶Er3+,Yb3+UCNPs。傅里叶变换红外光谱证明配体交换成功;扫描电镜表明UCNPs的形貌和尺寸没有改变;圆二色光谱表征亲合素偶联UCNPs前后二级结构变化较小。以亲合素化的NaYF4∶Er3+,Yb3+UCNPs为供体;受体为生物素标记的藻红蛋白。通过亲合素—生物素系统拉近供体和受体,引发共振能量传递。当体系中加入自由的生物素分子,它们竞争地与UCNPs表面的亲合素结合,抑制能量传递过程,从而荧光光谱发生变化。根据这种光谱变化与加入生物素量之间的关系,对其进行定量检测,获得了纳摩尔级的检测限。Upconversion nanoparticles（UCNPs） of small size have great potential in homogeneous assay based on fluorescence resonance energy transfer（FRET）.A novel approach of surface ligand-exchange for preparing water-soluble and amido-functionalized NaYF4∶Er3＋,Yb3＋ UCNPs with 12 nm was developed.The ligand exchange process was confirmed by Fourier transform infrared spectra.Investigations by scan electron microscopy showed no obvious variations in the size and shape of the UCNPs.The circular dichroism characterization demonstrates that the secondary structure of the avidin remains largely intact after the conjugation.Avidin-biotin served as a bridge to make the short enough distance for FRET between the acceptor biotinylated R-phycoerythrin and the donors avidin-conjugated UCNPs.When the free biotins were added into this system,they competitively combined with avidin on the UCNPs surface and impede the FRET to triggered fluorescence changes.According to the relationship between this change and the addition of the amount of biotin,such FRET-based approach can reach a limit of detection in the nanomolar concentration range.

关 键 词：上转换纳米晶 荧光共振能量传递 均相荧光分析 

分 类 号：O472.3[理学—半导体物理]