中文摘要：

采用改进的Hummers方法制备了纳米尺度的氧化石墨烯.对氧化石墨烯的表面进行羧基化,并连接上聚乙二醇（PEG）使其在细胞培养液中可溶并能稳定保存.采用透射电镜（TEM）、傅里叶变换红外（FTIR）光谱和zeta电位测量等对修饰后的氧化石墨烯的结构和功能进行了表征.体外细胞实验表明PEG修饰的氧化石墨烯在水中具有良好的可溶性,对A549细胞没有明显的毒性,在生物医药领域具有潜在的应用价值.

英文摘要：

We report on synthesis of nanoscale graphene oxide （NGO） by modified Hummers＇ method. Synthesized NGO particles were surface functionalized by attaching carboxylic acid and polyethylene glycol groups to render them soluble in cell culture medium. The structures and properties of functionalized NGO were characterized by transmission electron microscopy （TEM）, Fourier transform infrared （FTIR） spectroscopy, and zeta potential analyzer. Cell viability studies show that PEG-modified NGO particles are highly soluble and incur almost no cytotoxicity to A549 cells, which suggest a great potential for the use of NGO in various biomedical applications.