Abstract：Glucose oxidase (GOx) is a type of catalytic enzyme which has important value in industrial applications. GOx is capable of catalyzing glucose into gluconic acid with high efficiency and selectivity. However， its actual applications are limited by the poor environmental stability and tedious operating steps of activity determination. In this work， a cross-linkable molecule DAA-Flavin was synthesized， which had similar structure with the cofactor of glucose oxidase (GOx). DAA-Flavin was then copolymerized with main monomer acrylamide (AAm) around GOx surface to fabricate core-shell GOx nanocapsules. The enzyme serving as core was encapsulated in the functional polymer shell， which protected the enzyme from denaturation and improved its environmental stability. Moreover， cofactor-like fluorescent molecules DAA-Flavin distributed in the polymer shell could act as mediators to accept electron given by the enzymatic active center， thus endowing the nanocapsules redox fluorescent property. In the presence of substrate， fluorescence intensity of the nanocapsules was attenuated gradually due to the continuous reduction of DAA-Flavin， and there was a highly linear correlation between the fluorescence decay rate and enzyme activity (R2＞0.990). Furthermore， attenuated fluorescence intensity at reducing state could restore under oxidation condition， making the redox fluorescence reversible. The fabrication of this novel kind of core-shell enzyme nanocapsules enabled the conversion from biochemical signals to photoelectric signals， and endowed the enzymatic activity visual properties.
2024, Vol. 58 
