疏水上转换纳米晶的均相体系聚合物包覆及在发光检测中的应用

Surface Coating of Hydrophobic Up-converting Nanoparticles in Homogenous Liquid Phase System and Application in Optical Detection

选用水解的十八碳烯-马来酸酐共聚物(PMAO)为表面修饰分子,发展了一种以疏水纳米粒子吸附表面活性剂十二烷基磺酸钠(Na YF_4-SDS)为中间体的均一液相聚合物包覆纳米粒子方法.该方法解决了油溶性纳米晶与弱极性聚合物分子难以在单一体系下均匀分散的问题,实现了在均一液相体系下对疏水纳米晶的单分散包覆以及表面羧酸官能团修饰.红外光谱与表面Zeta电位测试结果表明纳米晶已被聚合物包覆,粒子表面为强电负性的羧酸基团.电镜结果表明聚合物包覆的上转换纳米晶粒径无明显的变化,具有良好的单分散性.发射光谱表明聚合物包覆前后粒子的发射谱带无显著变化,保持了原油相粒子的发光性能.进一步的特异性识别荧光显微成像实验证实聚合物包覆后的粒子(Na YF_4-PMAO)可用于生物学检测.

NaYF4∶ Yb^3＋,Er^3＋ nanoparticles were successfully surface-coated via a hydrophobic nanoparticles adsorption surfactant intermediate（ Na YF4-SDS） process with hydrolysed poly（ maleic anhydride-alt-1-octadecene） molecules（ PMAO）. This method overcomes the defect that oil-soluble nanocrystals and weak polar polymer molecules could hardly well-disperse in a single system and the surface-coating was realized in homogenous solution system. The surface-coating process was confirmed by Fourier transform infrared spectra（ FTIR） and surface Zeta potential. Investigations by transmission electron microscopy（ TEM） and photoluminescence（ PL） spectroscopy showed no obvious variations in the morphologies and luminescent properties of the nanoparticles during the surface-coating process. The specific molecular recognition capacity of PMAO-coated nanoparticles confirms that hydrophilic NaYF4-PMAO are suitable for potential biological labeling.