【摘要】 建立了一个基于磁性荧光双探针基础上的免疫快速检测体系,以实现液相中快速检测食品中2,4-二氯苯氧乙酸(2,4-D)残留.该体系将2,4-D抗体结合Fe3O4@SiO2-NH2得到的复合物作为磁性探针和固相载体,2,4-D-OVA被标记CdTe@SiO2-NH2作为荧光探针以产生荧光信号,通过荧光探针与磁性探针复合物与2,4-D抗体竞争结合实现免疫快速检测.探讨了荧光探针最佳优化条件,在p H值8.2,2,4-D-OVA加入量为500μL,偶联时间为70 min时,偶联得到的荧光信号最强,双探针检测后得到该检测体系最低检测限为3.55×10-8.得到金磁、量子点荧光双探针免疫系统,绘出标准曲线,得到最低检测限达3.55×10-8.该检测体系与传统ELISA方法相比,可以大大缩短检测时间,放大检测信号.更多还原

【Abstract】 A novel immunoassay system based on magnetic-fluorescent probes was established to detect 2. 4-dichlorophenoxyacetic acid( 2,4-D) residue in liquid system in food and agricultural products. The composites of anti-2,4-D antibody bound to Fe3O4@ SiO2-NH2 was employed as the solid phase as well as magnetic probe. The composites composed of 2,4-D-OVA labeled with Cd Te@ SiO2-NH2 as the fluorescent probe was used to produce fluorescent signal. 2,4-D and its fluorescent probe competed binding the antibody on the surface of the magnetic probe. The optimization of 2,4-D-OVA dosage,coupling PH and reaction time in preparing the fluorescent probe were investigated. It showed that in the synthesis of fluorescent probe 8. 2 was the optimal p H,70 min was the optimal coupling time,500 μL amount of 2,4-D-OVA. The standard curve was obtained with the concentration of 2,4-D and the maximum fluorescence intensity. The detection limit of the assay was gotten and it was3. 55 × 10- 8. One reaction step and one washing step were needed. The assay significantly shortened the testing time and amplified the detection signal compared with classic ELISA.更多还原