Figure 2.
GO as a hydroxyl-radical scavenger. A: Addition of 100 ppm GO protects phenol red from oxidation by Fenton-generated ·OH over 8 hrs. B: Addition of GO protects the spin-trap DMPO from oxidation by Fenton-generated ·OH detected by EPR spectroscopy. The protective effect is concentration dependent over the range 0.1-90 ppm GO. C: Both phenol red monitoring and EPR were used to test if the GO-mediated protective effect is due to radical scavenging or Fenton suppression by Fe-binding. The protective effect of GO is still present when GO-Fe binding is suppressed by EDTA, confirming the importance of radical scavenging. D: GO also protects DMPO when ·OH is generated sonochemically, in a non-Fenton assay, providing additional evidence for true radical scavenging. All experiments were done in PBS (pH 3.5).
