▎ 摘　　要

An optosensor based on synthesized magnetic composite sensing probes was designed to detect ultra-trace levels of cefoperazone. The nanocomposite probe integrated porous graphene, quantum dots, magnetite nanoparticles and highly specific polymer. These substances produced an ultra-sensitive, selective and rapid sensor. The fluorescence emission of the nanoprobes was quenched when cefoperazone interacted with the imprinted binding sites. The developed probe exhibited good linearity toward cefoperazone from 0.10 to 25.0 mu g L-1 and the limit of detection was 0.09 mu g L-1. The fabricated magnetic nanocomposite sensor showed good specificity for cefoperazone with an imprinting factor of 7.5 and was not interfered by the analog structures ceftriaxone, cefazolin, cefradine, ceftazidime and cefalexin. The nanocomposite probe successfully detected cefoperazone in milk. Recoveries ranged from 85.3 to 98.3% with RSDs < 6%. Analysis results agreed well with HPLC but the advantages of the optosensor include a simple, rapid procedure, cost-effective equipment and environmental friendliness.