选用2-胺乙基膦酸双官能团小分子作为配体交换剂，采用氯仿/乙醇/水三元混合溶剂体系下的配体交换修饰方法，解决了疏水纳米晶与亲水配体的有效接触反应问题，实现了上转换纳米晶的水溶性以及表面胺基功能化修饰。通过傅里叶变转换红外光谱和热重分析证实了表面配体分子的替换。透射电子显微镜和激光粒度分析结果显示，所得水溶性纳米晶具有粒径均一，水力直径小和分散稳定的特点。样品的发射光谱结果表明，配体交换过程对纳米晶的发光无明显影响，保持了良好的发光性能。通过荧光共聚焦成像技术实现了胺基修饰上转换发光纳米晶对HeLa细胞的光学成像，证实所得纳米晶适合于潜在的生物学应用。%Hydrophobic up-converting rare-earth nanoparticles( UCNPs) were transferred from organic solvent to aqueous solution via a simple surface-ligand exchange procedure. 2-Aminoethyl dihydrogen phosphate ( AEP) molecules were used to replace the original hydrophobic ligands in chloroform, ethanol and water ter-nary mixture solvent at ambient temperature. The ligand exchange process was confirmed by Fourier transform infrared spectra( FTIR) and thermogravimetric analysis( TG) . Investigations by transmission electron micros-copy(TEM), dynamic light scattering ( DLS) and photoluminescence ( PL) spectroscopy show no obvious variations in the morphologies, structure and luminescentproperties of the UCNPs during the ligand exchange process. The fluorescence confocal cell imaging of AEP modified hydrophilic UCNPs confirms that the hydro-philic UCNPs are suitable for potential biological labeling.
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