Bimetallic metal–organic framework for enzyme immobilization by biomimetic mineralization: Constructing a mimic enzyme and simultaneously immobilizing natural enzymes

An iron-nickel bimetallic metal-organic framework (FeNi-MOF) with inner peroxidase-like activity as a support for enzyme immobilization was synthesized for the first time. And the GOx-mediated synthesis of mimic multienzyme system (GOx/FeNi-MOF) was obtained by a one-step biomimetic mineralization. FeNi-MOF played a dual role of a peroxidase mimic and a protective coating. Therefore, the obtained multienzyme system showed both peroxidase-like activity of FeNi-MOF and the biological activity of natural enzyme. FeNi-MOF acted as a peroxidase mimic, showing a higher affinity for hydrogen peroxide (H2O2). The enhanced catalytic activity of the FeNi-MOF may result from synergistic effect between iron and nickel. In addition, the GOx/FeNi-MOF was selected as a proof of concept and succeeded in a one-step colorimetric detection of glucose by tandem catalysis. A small amount of the product was used for glucose detection, and the detection range was 0.3-35 mM, which indicated that our sensor can meet the clinical needs for diagnose diabetes.