Rational Design of MOF-Based Multifunctional Bio-Nanoreactor for Efficient Detection and Photo-Degradation of...

Food safety have received increasing attention in recent years, and rapid detection and thorough removal of organic contaminants is an important part of food safety control. In this work, a novel multi-functional photo-enzymatic nanoreactor HRP@Fe-NU-1003 is developed through the co-immobilization of horseradish peroxidase (HRP) and FeCl₂ on a photosensitive metal-organic frameworks (MOF) NU-1003. The bio-nanocluster can serve as an efficient biosensor in the detection of chloramphenicol (CAP), with a detection limit of 15.38 pg mL^-1, which is 62 times greater than that of the conventional HRP- enzyme-linked immunosorbent assay method. Besides its detecting capability, the nanoreactor also exhibits high efficiency in the photocatalytic degradation of CAP, which can remove 50 µg mL^-1 of CAP thoroughly within 30 min, and the mineralization efficiency of CAP reaches 61%. In this material, Fe-NU-1003 not only acts as a protecting shell to prevent HRP from deactivation, but improves detecting sensitivity and photocatalytic performance. Mechanism studies show that FeCl₂ enhances its photocatalytic performance through promoting electron (e^-)-hole (h⁺) separation and photocurrent transfer. More importantly, the heterogeneous material possesses high stability and can be recycled at least five rounds while its photocatalytic performance maintained at a high level. This strategy provides a new approach for the detection and degradation of pollutants.