The article discusses the synthesis and biological applications of nano-graphene oxide (NGO), which are single-layer graphene oxide sheets with lateral widths of a few nanometers. The researchers developed functionalization chemistry to enhance the solubility and biocompatibility of NGO in biological environments. They achieved size-separated pegylated NGO sheets that are soluble in buffers and serum without agglomeration. These NGO sheets exhibit photoluminescence in the visible and near-infrared (NIR) regions, making them suitable for live cell imaging with minimal background. The intrinsic photoluminescence of NGO is used for NIR imaging. Additionally, the researchers found that simple physisorption via π-stacking can be used to load doxorubicin, a widely used cancer drug, onto NGO functionalized with antibodies for selective killing of cancer cells in vitro. The small size, intrinsic optical properties, large specific surface area, low cost, and useful non-covalent interactions with aromatic drug molecules make NGO a promising material for biological and medical applications.The article discusses the synthesis and biological applications of nano-graphene oxide (NGO), which are single-layer graphene oxide sheets with lateral widths of a few nanometers. The researchers developed functionalization chemistry to enhance the solubility and biocompatibility of NGO in biological environments. They achieved size-separated pegylated NGO sheets that are soluble in buffers and serum without agglomeration. These NGO sheets exhibit photoluminescence in the visible and near-infrared (NIR) regions, making them suitable for live cell imaging with minimal background. The intrinsic photoluminescence of NGO is used for NIR imaging. Additionally, the researchers found that simple physisorption via π-stacking can be used to load doxorubicin, a widely used cancer drug, onto NGO functionalized with antibodies for selective killing of cancer cells in vitro. The small size, intrinsic optical properties, large specific surface area, low cost, and useful non-covalent interactions with aromatic drug molecules make NGO a promising material for biological and medical applications.