▎ 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.