RT info:eu-repo/semantics/article T1 Tuning the antioxidant activity of graphene quantum dots: Protective nanomaterials against dye decoloration A1 Ruiz Fernández, Virginia A1 Yate, Luis A1 García, Ignacio A1 Cabañero, Germán A1 Grande, Hans J. K1 Electroquímica K1 Electrochemistry K1 Electrotecnia K1 Electrical engineering AB The antioxidant activity of graphene quantum dots (GQD) with different chemical composition and sp2-hybridized carbon content has been evaluated and compared to that of a standard antioxidant, ascorbic acid. GQD were prepared by top down and bottom up synthetic approaches from three different precursors (carbon black, glucose and pyrene) in order to vary significantly the chemical composition, electron density and sp2-hybridized carbon content. For a given radical, the three types of GQD exhibited very different radical scavenging activity (RSA). Moreover, the RSA varied with the type of free radical and reactive oxygen species (ROS) tested, indicating different radical inhibition mechanisms. Overall, GQD with strong hydrogen donor behavior and large content of sp2–hybridized carbon domains were the most effective radical scavengers. Thus, highly graphitic GQD with abundant edge functional groups produced from pyrene exhibited an extraordinary high antioxidant activity, with inhibition effective concentrations much lower than those of ascorbic acid. The great potential of highly antioxidant GQD as protective films against organic dye decoloration by ROS was demonstrated with two model target molecules, methylene blue and rhodamine B. PB Elsevier SN 0008-6223 YR 2017 FD 2017-05 LK http://hdl.handle.net/10259/10304 UL http://hdl.handle.net/10259/10304 LA spa NO Financial support from the Basque Government under the ELKARTEK Program (ACTIMAT project, grant number KK-2015/00094 and KK-2016/00097) is gratefully acknowledged. DS Repositorio Institucional de la Universidad de Burgos RD 13-mar-2025