A novel enhanced enrichment glucose oxidase@ZIF-8 biomimetic strategy with 3-mercaptophenylboronic acid for highly efficient catalysis of glucose

Abstract

Herein, a glucose oxidase@ZIF-8 composite (3-MPBA/GOx@ZIF-8) with enhanced enrichment was enabled the rapid encapsulation of glucose oxidase (GOx) into microporous zeolitic imidazolate framework-8 (ZIF-8) for the first time. The 3-MPBA/GOx@ZIF-8 not only has improved affinity and catalytic efficiency to the substrate but also can shorten the formation time. The optimum loading amount of GOx on ZIF-8 was determined to be 470 mg/g. The as-prepared 3-MPBA/GOx@ZIF-8 composite maintained the native conformation of the enzyme and showed excellent bioactivity, even in chemical agents or at high temperature. Furthermore, the 3-MPBA/GOx@ZIF-8 showed satisfactory reusability, preserving almost 80.8 % activity after 7 cycles. The Michaelis constant K_m and specificity constant k_cat/K_m of the 3-MPBA/GOx@ZIF-8 were 0.03 ± 0.02 mM and 63.87 ± 1.96 s^-1 mM^-1, respectively, which were superior to corresponding values of free GOx. Therefore, the 3-MPBA/GOx@ZIF-8 displayed high catalytic efficiency, high loading efficiency and enhanced stability. Moreover, a new type of visual colorimetric sensor for screening of the diabetes was realized through the 3-MPBA/GOx@ZIF-8, which provided a new strategy for the analysis field of glucose.

Keywords: 3-Mercaptophenylboronic acid; Encapsulation; Glucose; Glucose oxidase; ZIF-8.