A novel biosensor based on boronic acid functionalized metal-organic frameworks for the determination of hydrogen peroxide released from living cells

In this work, we report a durable and sensitive H2O2 biosensor based on boronic acid functionalized metal-organic frameworks (denoted as MIL-100(Cr)-B) as an efficient immobilization matrix of horseradish peroxidase (HRP). MIL-100(Cr)-B features a hierarchical porous structure, extremely high surface area, and sufficient recognition sites, which can significantly increase HRP loading and prevent them from leakage and deactivation. The H2O2 biosensor can be easily achieved without any complex processing. Meanwhile, the immobilized HRP exhibited enhanced stability and remarkable catalytic activity towards H2O2 reduction. Under optimal conditions, the biosensor showed a fast response time (less than 4 s) to H2O2 in a wide linear range of 0.5-3000 μM with a low detection limit of 0.1 μM, as well as good anti-interference ability and long-term storage stability. These excellent performances substantially enable the proposed biosensor to be used for the real-time detection of H2O2 released from living cells with satisfactory results, thus showing the potential application in the study of H2O2-involved dynamic pathological and physiological process.