Toxicological properties of two fluorescent carbon quantum dots with onion ring morphology and their usefulness as bioimaging agents

In the present work, two carbon quantum dots with onion ring morphology, C-NOR and C-NOR(Eu) with an average size of 40 nm differing in the absence or presence of Eu3+ as Lewis acids during their preparation were synthesized and fully characterized by several techniques. These nanoparticles can be internalized into human HeLa and Hep3B carcinoma cells where they exhibit interesting photoluminescent properties, in the same manner as in solution, confirming their utility as bioimaging agents. To address this possibility, a complete in vitro toxicological study has been performed here. Viability, proliferation, apoptosis and oxidative stress assessments upon limited or continuous exposure were…