Surface engineering of carbon dots for highly sensitive -glucosidase assay and inhibition evaluation

Monitoring alpha-glucosidase ( alpha-Glu) activity is of great significance for the early diagnosis of type II diabetes. Here the blue fluorescent carbon dots (CDs) were integrated with two different recognizing molecules, beta-cyclodextrin and phenylboronic acid, for assembling a multifunctional CDs (mCDs) nanoplatform for sensitively analyzing alpha-Glu and its inhibitors. The hydrolyzed product of 4-nitrophenyl- alpha- D glucopyranoside ( alpha-Glu substrate), p -nitrophenol, could efficiently quench the fluorescence of mCDs due to its cooperative molecular recognition with beta-cyclodextrin and phenylboronic acid. The mCDs could be utilized for the detection of alpha-Glu activity with the limit of detection of 0.030 U/L. Moreover, the present alpha-Glu detection platform revealed a high selectivity, and other natural enzymes showed scarcely any effect on the present mCDs system. The proposed method could be facilely used to screen alpha-Glu inhibitors with satisfying performance. The rational mCDs is expected to supplement more comprehensive biosensing platforms for highly sensitive and specific recognition of disease-relevant biomarkers with clinical importance.(c) 2023 Published by Elsevier B.V. on behalf of Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences.