▎ 摘　　要

A fluorescent probe was fabricated and applied to determine marbofloxacin. The fluorescent probe integrated nitrogen-doped graphene quantum dots, hydroxylated-halloysite, and magnetite nanoparticles into molecularly imprinted polymer (OH-HNTs@N-GQDs@Fe3O4@MIP). The determination of marbofloxacin was performed by measuring the reduction in the fluorescence emission of the probe when marbofloxacin bound to the recognition sites of the MIP. The intensity of the nanoprobe was quenched linearly from 0.10 to 25.0 mu g L-1 and the limit of detection was 0.03 mu g L-1. The fluorescent nanoprobe was selective for marbofloxacin with did not quenched fluorescence emission by other similar structure compounds. The fabricated magnetic probe was applied to determine marbofloxacin in milk. Good recoveries from 94.2 to 99.6 % were achieved and RSDs were<5 %. The accuracy of the proposed probe was good, and results were in good agreement with results from chromatographic analysis. The developed method exhibited high sensitivity and a fast response. The analysis is simple and cheap to perform, environmentally friendly and can be applied to determine trace contaminants in various food.