Fe-Hemin-Metal Organic Frameworks/Three-Dimensional Graphene Composites with Efficient Peroxidase-Like Bioactivity for Real-Time Electrochemical Detection of Extracellular Hydrogen Peroxide

Real-time detection of extracellular hydrogen peroxide is important for dynamic monitoring of diseases and cytopathological research. Here, a novel composite of Fe-hemin-metal organic frameworks/three-dimensional graphene (Fe-hemin MOFs/3DG) was prepared by embedding hemin into amino-contained Fe-MOFs, then decorated with 3DG. The obtained Fe-hemin MOFs/3DG possessed efficient peroxidase-like bioactivity and could serve as an effective catalyst for construction of H2O2 electrochemical sensor. The electrochemical results show that the proposed sensor based on Fe-hemin MOFs/3DG has excellent catalytic activity for H2O2. With a linear range was 10−12080 μM and LOD was 0.34 μM, this sensor showed favorable selectivity, repeatability and stability, which could be used to detect H2O2 in real serum samples. Most importantly, this sensor realized the real-time determination of H2O2 released by A549 cells and possessed good biocompatibility. The outstanding electrochemical performance mainly benefited from the unique porous structure of MOFs, which could effectively protect the active center of hemin, and the introduction of 3DG greatly improved the conductivity of Fe-hemin MOFs. Therefore, the Fe-hemin MOFs/3DG could be a promising probe for real-time dynamic monitoring of H2O2.