A fluorometric and real-time assay for α-glucosidase activity through supramolecular self-assembly and its application for inhibitor screening

- Detection strategy based on suparmolecular self-assembly was designed.
- A sensitive assay for α-glucosidase activity based on β-CD-CQDs was developed.
- The function of the assay to screen inhibitors of α-glucosidase was assessed using acarbose.

A fluorometric biosensor has been developed to sensitively detect α-glucosidase activity and screen α-glucosidase inhibitors based on carbon quantum dots nanoprobe through supramolecular self-assembly. β-Cyclodextrin was covalently bonded to the surface of carbon quantum dots to prepare β-CD-CQDs nanoprobe. The presence of 4-nitrophenol drives self-assembly between β-CD-CQDs nanoprobe and 4-nitrophenol through host-guest recognition. This supramolecular assembly exhibits non-fluorescent nature, which results in strong quenching of the fluorescence of β-CD-CQDs nanoprobe. When 4-nitrophenyl-α-d-glucopyranoside was chosen as the substrate, it would be readily hydrolyzed to 4-nitrophenol in the presence of α-glucosidase. The linear correlation of quenched fluorescence to α-glucosidase level can be used to establish quantitative detection of α-glucosidase activity. The detection limit of this method can be lowered as 0.6 U/L, and possesses excellent sensitivity and selectivity. The function of this method to screen inhibitor of α-glucosidase was also assessed using acarbose as the example, and positive results supported its feasibility to screen potential inhibitors of α-glucosidase. This work proposes a new signal transduction mechanism through supramolecular assembly, and provides a sensitive detection method for α-glucosidase activity.

A fluorometric biosensor has been developed to sensitively detect α-glucosidase activity and screen α-glucosidase inhibitors based on carbon quantum dots nanoprobe through supramolecular self-assembly.98