Fluorescent carbon nanoparticles synthesized from bovine serum albumin nanoparticles

Fluorescent carbon based-nanoparticles are one of the emerging nanomaterials. Their preparation is relatively simple, rapid and inexpensive, and they are less toxic compared with metal and semiconductor nanoparticles. Here, we report a simple and reliable method to prepare water-soluble fluorescent carbon nanoparticles (FC-NPs) from nanoparticles made from a protein, bovine serum albumin. The obtained mean size of our carbon nanoparticles is between 3.8 and 3.4 nm, and they exhibit its maximum fluorescence emission at 424 and 408 nm respectively (with a reasonable QY of 16.5%) due to the presence of functional groups (NH, NH2, COOH and OH) that contain O and N; the presence of these functional groups was confirmed by FTIR and XPS analysis. The photoluminescent decay lifetime was modeled by a two exponential fit which indicates a contribution from both core and surface states. Also, the preliminary results showed that FC-NPs had a good interaction with HeLa and normal oral epithelial cells; nanoparticles were permeable at the cell membrane and went to the cytosol, and even to the nucleus, in less than 30 min, the fluorescence images of our preliminary results did not show any apparent toxic damage in any of the cell lines.