Copper nanocomposite decorated two-dimensional metal organic frameworks of metalloporphyrin with peroxidase-mimicking activity

Abstract

Two-dimensional nanosheets of metalloporphyrin are promising in biomimetic catalysis due to the activity of metalloporphyrin and the ultrathin structure with highly accessible active sites. Many efforts have been devoted to incorporate noble metallic nanoparticles with metalloporphyrinic nanosheets to enhance the catalytic performance. In this paper, a hybrid nanosheet with peroxidase-like activity is constructed by growth of non-precious copper nanocomposites onto nanosheets of metal organic framework (MOF) that have tetrakis-(4-carboxyphenyl)-porphyrin iron (FeTCPP) ligands linked by copper clusters, designated as Cu@Cu-FeTCPP. The copper hydroxide-copper oxide (Cu(OH)2-CuO) heterogeneous composites with nanoparticles, nanoneedles and nanorods structures are uniformly distributed on the surface of metalloporphyrinic nanosheets (Cu-FeTCPP). The synthesized Cu@Cu-FeTCPP nanohybrids shows enhanced peroxidase-mimicking catalytic performance compared to the free copper composites, Cu-FeTCPP nanosheets, and their mixture, because of the synergistic effect between nanosheets and copper nanocomposites. Lower Michaelis−Menten constants Km prove the better affinity of the nanohybrids with substrates than Cu-FeTCPP MOFs, even than HRP. Based on the high peroxidase-like catalytic activity, Cu@Cu-FeTCPP nanohybrids are successfully applied to decolorization of Congo Red and detection of glucose with high efficiency and high sensitivity.