β-Cyclodextrin functionalized persistent luminecence nanoparticle for autofluorescence-free detection of α-glucosidase activity and its inhibitor

The development of simple, selective and sensitive analytical methods to effectively monitor α-glucosidase (α-Glu) and discover its new inhibitors is very critical for the diagnosis and treatment of diabetes. Herein, an autofluorescence-free sensing method based on β-cyclodextrin (β-CD) functionalized persistent luminescence nanoparticle (PLNP) is established for the detection of α-Glu activity and its inhibitor. The p-nitrophenol (PNP) produced by the hydrolysis of substrate p-nitrobenzene-α-D-glucopyranoside (PNPG) by α-Glu in the system can be selectively captured by the β-CD on the nanoprobe to form adducts through the host guest effect between them, resulting in persistent luminescence quenching due to electron transfer (ET) effect. The proposed method provides a good linear relationship within the range of 5–80 U/L and a low detection limit of 0.9 U/L, and can detect α-Glu in human serum with the recovery rate of 95.4–103.3 %. Furthermore, the detection system can measure the inhibitory ability of acarbose with an IC 50 value of 349 μM, proving its good potential for application.