ACS Appl. Nano Mater. 2022, 5 (9): 12626–12636

Effects of lateral size, thickness, and stabilizer concentration on the cytotoxicity of defect-free graphene nanosheets: implications for biological applications

Chen-Xia Hu, Oliver Read, Yuyoung Shin, Yingxian Chen, Jingjing Wang, Matthew Boyes, Niting Zeng, Adyasha Panigrahi, Kostas Kostarelos, Igor Larrosa, Sandra Vranic*, Cinzia Casiraghi*

In this work, we apply liquid cascade centrifugation to highly concentrated graphene dispersions produced by liquid-phase exfoliation in water with an insoluble bis-pyrene stabilizer to obtain fractions containing nanosheets with different lateral size distributions. The concentration, stability, size, thickness, and the cytotoxicity profile are studied as a function of the initial stabilizer concentration for each fraction. Our results show that there is a critical initial amount of stabilizer (0.4 mg/mL) above which the dispersions show reduced concentration, stability, and biocompatibility, no matter the lateral size of the flakes.