A facile one-pot synthesis of hemin/ZIF-8 composite as mimetic peroxidase

A hemin/ZIF-8 composite has been prepared for the first time by one-pot via chemical bond interactions between ZIF-8 and hemin molecules. TEM, EDX and BET analysis suggest that hemin/ZIF-8 has mesoporous structure and hemin is uniformly distributed in the framework of ZIF-8. FTIR analysis shows that the -COOH groups are combined with metal ion. XRF analysis shows that the loading amount of hemin in the composite is 3.32%. It shows a good peroxidase-like activity for the oxidation of substrate 3,3,5,5-tetramethylbenzidine (TMB) in the presence of H2O2 in aqueous solution. We discover that the imidazole, metal ion and pure ZIF-8 can improve activity of hemin, especially the imidazole. So the microenvironment provided by ZIF-8 plays an important role in improving the catalytic activity.