Enzyme-integrated metal-organic framework platform for cascade detection of α-amylase.

As one of the most important industrial enzymes, α-amylase is widely used in food processing, such as starch sugar and fermentation, bringing high added value to industry of more than a trillion dollars. We developed a multi-enzyme system (Glu&Gox@Cu-MOF-74) prepared by embedding α-glucosidase (Glu) and glucose oxidase (Gox) into the biomimetic metal-organic framework Cu-MOF-74 using in situ encapsulation within 15 min at room temperature for efficient and sensitive detection of α-amylase activity. Benefitting from the remarkable peroxidase-mimicking property and rigid skeleton of Cu-MOF-74, the biocatalytic platform exhibited excellent cascade activity and tolerance in various extremely harsh environments compared to natural enzymes. On this basis, a cascade biocatalytic platform was constructed for the detection of α-amylase activity with wide linear range (5-100 U/L) and low limit of detection (1.45 U/L). The colorimetric cascade scheme is important for the sensitive and selective determination of α-amylase in complex fermentation samples, and the detection time is short (∼0.5 h). This work provides new ideas for the detection of α-amylase based on the cascade amplification method.