Novel PEI-AuNPs-MnIIIPPIX nanocomposite with enhanced peroxidase-like catalytic activity in aqueous media

Mn porphyrin provides a possibility to constitute the novel mimic catalyst with peroxidase-like activity. A simple method for preparing a novel catalyst PEI-AuNPs-MnIIIPPIX, used in aqueous media, was presented in this paper. The covalent anchoring of MnIIIPPIX and PEI were verified, meanwhile gold nanoparticles with the diameter less than 10 nm were dispersed uniformly and stably. The remarkable peroxidase-like catalytic activity of PEI-AuNPs-MnIIIPPIX was displayed in the oxidative degradation of azo dye acid orange 7 (AO7) as the model reaction in the presence of trace of H2O2. The synergistic effects of PEI-AuNPs and MnIIIPPIX on the enhancement of catalytic activity were observed at pH 2.0. Possible pathways involving in the formation of active radicals are proposed. The construction of PEI-AuNPs-MnIIIPPIX nanocomposite offers a new insight into the application of Mn porphyrin upon activation of H2O2, which have potential applications in many fields.