Enhancing catalytic activity of smart polymer-UiO-66@GOx-HRP through temperature change for colorimetric detection of glucose

Metal-organic frameworks (MOFs) have attracted extensively interests for enzyme immobilization. However, their rigid structures remain a great challenge in improvement the catalytic performance of the carriers due to no nanoconfinement. Herein, carriers based on rigid UiO-66-NH 2 (U) modified with soft smart polymer were designed by surface engineering. A thermo-responsive polymer, poly(N-isopropylacrylamide) (PNP), was synthesized through an in-situ polymerization strategy, which was employed as a “soft tent” on the surface of rigid U. Glucose oxidase (GOx)-horseradish peroxidase (HRP) was chemically bonded on PNP-U using glutaraldehyde as a linker. Benefiting from the nanoconfinement via variation temperatures, PNP-U@GOx-HRP carriers exhibited 2.01-fold catalytic activity ( K cat value) at 37 °C higher than that at 25 °C. Furthermore, a colorimetric method for analysis of glucose in grape samples was developed. This study offers a strategy for construction of “soft tent” smart polymer-MOFs@enzyme carriers, which provides a pivotal nanoconfinement for boosting their catalytic performance, and broadens their applications in bio-molecules sensing.