▎ 摘　　要

Based on the static fluorescence quenching effects of benzoquinones on graphene quantum dots (GQDs), a GQDs-based fluorescent probe was established to detect the activity of alkaline phosphatase (ALP). Under the catalytic action of horseradish peroxidase, hydrogen peroxide (H2O2) could generate hydroxyl radicals (center dot OH), and center dot OH oxidized o-dihydroxybenzene to produce o-benzoquinone subsequently, resulting in the fluorescence quenching of GQDs. ALP catalyzed the production of reductive ascorbic acid by ascorbic acid 2-phosphat. Ascorbic acid efficiently removed H2O2 and center dot OH from the solution, leading to the inhibition of the production of o-benzoquinone and the fluorescence recovery of GQDs. Therefore, a highly sensitive determination strategy for ALP activity was established. Under the optimal experimental conditions, the detection limit of ALP activity was 0.084 U/L. This method was used to evaluate ALP activity in human serum samples. Such approach can provide theoretical basis for the diagnosis and treatment of ALP-related diseases.