Highly Efficient Electrochemical Detection of Phenolic Compounds Utilizing Superior Catalytic Activity of Nanohybrids Consisting of Magnetic Nanoparticles and Gold Nanoclusters.

Although Fe3O4 magnetic nanoparticles (MNPs) have gathered particular interest as potent peroxidase mimetics, their practical utility has been critically limited by their low catalytic activity. Here, we have developed a nanohybrid material to significantly enhance the catalytic activity of MNPs by incorporating other enzyme mimetics, gold nanoclusters (AuNCs), through electrostatic attraction. Owing to the synergistic effect of MNPs and AuNCs, the constructed nanohybrid yielded highly enhanced peroxidase-like activity and higher resolution in electrochemical detection of H2O2 than bare MNPs. The nanohybrids were also successfully applied to detecting phenolic compounds including phenol and cresol, producing a concentration-dependent increase of cathodic current. Based on this result, we expect that the nanohybrids consisting of AuNCs and MNPs can serve as potent peroxidase mimetics for environmental monitoring.