Department of Chemistry, Northeastern University, Shenyang 110819, China.
Langmuir. 2011 Dec 6;27(23):14632-7. doi: 10.1021/la204015m. Epub 2011 Nov 9.
This work reports the novel microwave-assisted solvothermal synthesis and structural, topographic, spectroscopic characterization of NaYF(4):Yb,Er upconversion nanoparticles (UCNPs) as well as their application in the labeling of HeLa cells. The nanoparticles were prepared in ethylene glycol, with rare earth acetates as precursor and NH(4)F and NaCl as the fluorine and sodium sources. X-ray diffraction, transmission electron microscopy, and luminescence spectroscopy were applied to characterize the nanoparticles. Experimental results showed that the microwave-assisted solvothermal method is an effective approach to create highly crystalline, strongly luminescent UCNPs at a lower temperature (160 °C) and within a significantly shortened reaction time (only 1 h) compared to the traditional methods. The effect of fluorine source on the optical properties of UCNPs was investigated by using NH(4)F, NH(4)HF(2), NaF, and 1-butyl-3-methylimidazolium tetrafluoroborate (BmimBF(4)) as different fluorine sources; NH(4)F proved to be the best one, making the luminescent intensity increase at least 2 orders of magnitude. The UCNPs with four different colors (green, yellow, orange, and cyan) were successfully obtained. After being modified with amino groups and coupled with CEA-8 antibody, the obtained nanoparticles were successfully applied in the specific fluorescent immunolabeling and imaging of HeLa cells to further verify their function as a marker in immunolabeling.
这项工作报道了新型微波辅助溶剂热合成和结构、形貌、光谱表征的 NaYF(4):Yb,Er 上转换纳米粒子（UCNPs），以及它们在 HeLa 细胞标记中的应用。纳米粒子是在乙二醇中，以稀土醋酸盐为前体，以 NH(4)F 和 NaCl 为氟源和钠源制备的。X 射线衍射、透射电子显微镜和荧光光谱用于表征纳米粒子。实验结果表明，与传统方法相比，微波辅助溶剂热法是一种在较低温度（160°C）和较短反应时间（仅 1 小时）下制备高结晶度、强发光 UCNPs 的有效方法。通过使用 NH(4)F、NH(4)HF(2)、NaF 和 1-丁基-3-甲基咪唑四氟硼酸盐（BmimBF(4))作为不同的氟源，研究了氟源对 UCNPs 光学性质的影响；结果表明，NH(4)F 是最佳的氟源，使发光强度至少增加了 2 个数量级。成功获得了四种不同颜色（绿色、黄色、橙色和青色）的 UCNPs。经过氨基修饰并与 CEA-8 抗体偶联后，所得纳米粒子成功应用于 HeLa 细胞的特异性荧光免疫标记和成像，进一步验证了它们作为免疫标记标志物的功能。
