Fig. 2

ROS generation by catalytic activities of FeGPNPs. a UV–vis absorbance spectra and color changes of TMB in different reaction systems after 5 min of incubation at 37 °C. 1-TMB; 2-TMB + H₂O₂; 3-FeGPNPs + TMB + H₂O₂. b Time-dependent absorbance changes at 652 nm using different concentrations of FeGPNPs as Fenton catalysts. c Kinetic assay for catalytic activity of FeGPNPs with H₂O₂ substrate. d Degradation of MB triggered by H₂O₂, FeGPNPs, and FeGPNPs + H₂O₂ after 3 h of incubation at 37 °C. e Time-dependent UV–vis spectra of MB degradation caused by FeGPNPs + H₂O₂. f Generation of ·OH by FeGPNPs in presence of 1.0 mM H₂O₂, determined by ESR