Biomedical Instrumentation Section, Materials Physics & Engineering Division, National Physical Laboratory, K. S. Krishnan Marg, New Delhi 110012, India.
Spectrochim Acta A Mol Biomol Spectrosc. 2012 Feb;86:432-6. doi: 10.1016/j.saa.2011.10.063. Epub 2011 Nov 3.
Silica surface-modified NdF(3) core-shell nanoparticles were prepared by sol-gel route. The prepared core-shell nanoparticles were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), UV-vis absorption and photoluminescence (PL) spectroscopy studies. Phase identification of the NdF(3) and silica-coated NdF(3) core-shell nanoparticles which was carried-out by XRD, confirms the formation of a well-crystallized hexagonal phase structure. Due to the silica-surface modification, the nanoparticles were not found to be well-separated (agglomerated) in ethanol solvent as scanned by TEM. The results of the FTIR studies conducted on these core-shell reveal the binding of silica with the NdF(3) nanoparticles. The largest intensity and shape variation were observed in all transitions as compared to non-silica modified NdF(3) nanoparticle spectra, and were attributed to the environment around the Nd(III) ion due to coordination of silica molecule(s). A significant enhancement in the emission intensity was measured in silica surface modified NdF(3) core-shell nanoparticles due to the successful silica coating on the surface of nanoparticles. The results of these studies suggest that these nanoparticles may find potential applications in the areas of bioimaging, protein-labeling, optical biosensors and drug delivery, etc.
采用溶胶-凝胶法制备了表面修饰二氧化硅的 NdF(3)核壳纳米粒子。采用 X 射线衍射（XRD）、透射电子显微镜（TEM）、傅里叶变换红外光谱（FTIR）、紫外-可见吸收和光致发光（PL）光谱研究对所制备的核壳纳米粒子进行了表征。通过 XRD 对 NdF(3)和二氧化硅包覆 NdF(3)核壳纳米粒子的相鉴定，证实了具有良好结晶的六方相结构的形成。由于二氧化硅表面修饰，TEM 扫描未发现纳米粒子在乙醇溶剂中良好分离（团聚）。对这些核壳进行的 FTIR 研究结果表明，二氧化硅与 NdF(3)纳米粒子结合。与未修饰的 NdF(3)纳米粒子的光谱相比，所有跃迁的强度和形状变化最大，这归因于由于二氧化硅分子的配位，Nd(III)离子周围的环境。由于纳米粒子表面成功包覆二氧化硅，在二氧化硅表面修饰的 NdF(3)核壳纳米粒子中测量到发射强度的显著增强。这些研究结果表明，这些纳米粒子可能在生物成像、蛋白质标记、光学生物传感器和药物输送等领域有潜在的应用。
